# Elon Smart

Documentation for the Elon Smart Series product range, including brochures, specifications, installation manuals, and troubleshooting guides.

# Brochures

# Elon Smart Water Brochure

Download the Elon Smart Water Brochure brochure using the attachment below.

# Kwikot Elon Smart_ Flyer_FA_WEB

Download the Kwikot Elon Smart\_ Flyer\_FA\_WEB brochure using the attachment below.

# Product Specifications

# PowerOptimal Elon® Smart thermostat specification V1.15

 *INTRODUCING THE*

 *PowerOptimal Elon® Smart Thermostat*

***The Elon Smart Thermostat transforms standard electric geysers into smart, solar PV-ready green appliances. Android & iOS apps allow monitoring and management with your smartphone, including water temperature and grid & solar energy use. Real-time monitoring and communication deliver actionable data. Early alerts for leak detection, element failure and other geyser faults reduce cost, damage and inconvenience. Simple installation with plug- and-play solar PV enables cost savings and reduced reliability on fossil fuels, improving quality of life.***

Document Version: 1.15

*SPECIFICATIONS*

<table id="bkmrk-rated-input-voltage2"><tr><td>Rated input voltage

</td><td>230V AC, 230V DC

</td></tr><tr><td>Rated input current

</td><td>18A AC, 15A DC

</td></tr><tr><td>Mains (AC) voltage range

</td><td>230V +10% -15%

</td></tr><tr><td>System power supply

</td><td>Solar PV DC or 230V AC mains

</td></tr><tr><td>Power consumption

</td><td>3W on either AC or DC (solar) power

</td></tr><tr><td>Data retention on device

</td><td>2 weeks for high-resolution server data, 1 year for mobile app data

</td></tr><tr><td>Solar voltage

</td><td>30 – 230 V DC

</td></tr><tr><td>Thermostat

</td><td>Electronic thermostat with 0.5 °C accuracy

</td></tr><tr><td>Safety

</td><td>Electromechanical thermal cutout

</td></tr><tr><td>Reverse polarity protection

</td><td>For solar PV connections

</td></tr><tr><td>Lightning protection

</td><td>8 kA

</td></tr><tr><td>Self-tests

</td><td>Component failure, wiring failure, element failure, insulation failure, hot connection

</td></tr><tr><td>Enclosure ingress protection rating

</td><td>IP40

</td></tr><tr><td>Radiated immunity

</td><td>IEC 61000-4-3 Level 3, 10 V/m

</td></tr><tr><td>Annual energy production compared to inverter-based system

</td><td>&gt; 90% when solar PV array and geyser element are matched correctly

</td></tr><tr><td>Standards conformance

</td><td>SANS 60730-1, SANS 60730-2-9, SANS / EN 301 489-1, SANS / EN 301 489-17, ICASA Type Approval, LoA from NRCS

</td></tr><tr><td>Dimensions &amp; weight

</td><td>23 x 12 x 11 cm, 0.3 kg. Box dimensions: 27.6 x 17.5 x 13.5 cm

</td></tr><tr><td>Patents

</td><td>Granted: ZA2019/02129, GB2583814B, ZA2022/08516, EP 4100979, US 12,122,914, GB2618349, ZA2024/08399, EP4519612

Pending: PCT/ZA2024/050065, CN2023800381161, US 18/861,142, AU2023265634, ZA2023/11726, ZA2024/08845, PCT/ZA2025/050066

</td></tr><tr><td>Registered Designs

</td><td>ZA F2022/00962, F2022/00963

</td></tr><tr><td>Communications link

</td><td>Wi-Fi Client, Wi-Fi Hotspot (2.4 GHz)

</td></tr><tr><td>Measurements

</td><td>AC energy, voltage, current (5%)

DC energy, voltage, current (5%)

Temperature: water &amp; ambient

</td></tr><tr><td>Data logging

</td><td>15-second data retained for 14 days

5-minute data retained for 366 days

</td></tr><tr><td>Other features

</td><td>Mobile app for installers and users

Full installation self-check

Remote firmware upgrades

50 000+ switching operations on thermostat

Cloud backend for remote monitoring &amp; alerts

Estimation of water use

</td></tr><tr><td>Advanced features scheduled for external availability in H2 2026

</td><td>Leak detection (software-based)

Anode condition monitoring

</td></tr></table>

It is important to match the solar PV array and heating elements for maximum power transfer efficiency. Refer to the **table below** for the recommended AC heating element power rating for different solar panel specifications and configurations.

***TABLE 1. GUIDE: PV ARRAY AND GEYSER (WATER HEATER) ELEMENT MATCHING***

<table id="bkmrk-solar-pv-array-size%28"><tr><td>**Solar PV array size**

**(kW<sub>p</sub>)**

</td><td>**Best matching geyser element size**

**(kW)**

</td><td>**2<sup>nd</sup> choice geyser element size\***

**(kW)**

</td><td>**Geyser (water tank) size**

**(litres)**

</td></tr><tr><td>**1 – 1.6**

</td><td>**4**

</td><td>3

</td><td>100 - 200

</td></tr><tr><td>**1.6 – 2**

</td><td>**3**

</td><td>4 or 2

</td><td>100 - 200

</td></tr><tr><td>**2 – 3**

</td><td>**3**

</td><td>4

</td><td>150 – 300

</td></tr></table>

*\* Second choice element size would reduce efficiency by 10 – 20%.*

**DO NOT DEVIATE FROM THE RECOMMENDED MODULE-ELEMENT MATCHING CONFIGURATIONS WITHOUT CONSULTING POWEROPTIMAL.**

**Maximum** **allowed** solar PV array specifications at Standard Test Conditions (**STC**):

 **I<sub>sc</sub> &lt; 15A V<sub>oc</sub> &lt; 230V Power &lt; 3 kW<sub>p</sub>**

Contact PowerOptimal for advice on module-element matching if module properties are significantly different to typical values or for **bifacial, high current or high voltage modules**.

<a id="bkmrk--4"></a>

# Installation & User Manuals

# ELON® SMART – Quick Start User Guide v3

## Elon® Smart Hot Water

Quick Start User Guide

Download the App

Get the Elon Smart app from the Apple App Store (iPhone) or

Google Play Store (Android).

Open the App

Launch the app on your phone.

Add Your Geyser Info

Tap the + button in the app.

Scan the Elon Smart QR code inside your DB board.

→ Your geyser will now appear in the app.

View Your Geyser Info

Tap your geyser in the app to see:

Current water Temperature

Solar and grid energy use

Temperature set points

Android iPhone

Scan QR code to install

Elon Smart App on your phone

## Get Your Elon® Online

Access the Thermostat Settings

In the app, tap the Settings (⚙) button next to your Elon Smart device.

The app will ask to connect to the thermostat’s built-in Wi-Fi hotspot → Tap

## “Connect.“

After connecting, the Thermostat Settings screen will open.

Set Up Wi-Fi for the Thermostat:

Tap “Wi-Fi Hotspot.” The app will search and display nearby Wi-Fi networks.

Select the Wi-Fi network you want the thermostat to use.

Enter the Wi-Fi password.

Tap “Test Connection.”

Check for a Successful Connection:

If the password is correct, the app will return to the Thermostat Settings screen.

Your chosen Wi-Fi network will now be shown with a green Wi-Fi icon → this

means the thermostat is successfully connected to the internet.

## Setting Temperatures &amp; Heating Schedules:

Access the Thermostat Settings

In the app, tap the Settings (⚙) button next to your Elon Smart device.

The app will ask to connect to the thermostat’s built-in Wi-Fi hotspot → Tap

## “Connect.“

After connecting, the Thermostat Settings screen will open.

Set Your Temperatures:

Enter your preferred temperatures for:

Target Solar Temperature (heats with solar power)

Target Grid Temperature (heats with mains electricity)

Recommended settings:

Solar: 65 °C

Grid: 50 °C

Choose a Heating Profile:

Select how your household uses hot water.

→ A good starting point is “Morning and Evening Shower.”

Save Your Settings:

Tap Save. The app will return to the main settings screen with your updated values.

# PowerOptimal Elon® Smart Installation Manual v1.19

![img-001.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/CD3img-001.png)

<a id="bkmrk--2"></a>

<a id="bkmrk--4"></a>

![img-002.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/iR2img-002.png)

![img-003.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/lXaimg-003.png)**PowerOptimal Elon® Smart Thermostat**

**Installation Manual**

Version number: <a id="bkmrk--7"></a>1.19

 Version date: 2025/12/28

Enquiries: <info@poweroptimal.com>

 Address: 88 12<sup>th</sup> Avenue

 Kleinmond

 7195

**Please note:** Always check the Elon Smart website for the latest version of this manual.

<a id="bkmrk--10"></a>Patented: GB2583814, ZA2019/02129, ZA2022/08516, EP4100979,

US 12,112,914, GB2618349, ZA2024/08399

Patents pending: PCT/ZA2024/050065, CH2023800381161, US 18/861,142, EP4519612, AU2023264634, ZA2023/11726, ZA2024/08845

![img-004.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/qQ3img-004.png)

**SAFETY WARNING**

- The Elon® Smart should **only be installed in standard Kwikot electric geysers**. It is NOT compatible with other geyser brands.
- We strongly recommend that the Elon Smart is only installed by a qualified plumber or electrician.
- If you are installing solar PV together with the Elon Smart, we strongly recommend that you use a reputable and experienced solar photovoltaic (PV) system installer to install your solar PV modules, and strictly according to the installation instructions in this installation manual.
- Installers should wear the appropriate safety and personal protective equipment (for example a safety harness and/or fall protection equipment when working at height).
- **The solar PV modules and wiring installation must be signed off by an electrical contractor registered with the Department of Labour** (the so-called “wireman’s licence”) The electrician must provide you with a **supplementary Certificate of Compliance (CoC)** once installation is completed. (A supplementary CoC is not required if only the Elon Smart is installed with no solar PV.)
- **Solar PV modules exposed to the sun are live** (i.e. will produce electricity) and can give an electric shock. Special care should be taken and only trained solar PV installers should install the modules.
- **Do not attempt to** alter or service the electrical installation, or open the Elon® Smart unit or controller for any purpose.
- Use the Elon® Smart **only for its intended purpose**.
- **Always** make sure that every wiring connection is **properly tightened**.
- **Do not earth** either of the solar module wires (but do earth the frames).
- All installation wiring should be at least 2.5mm².
- Avoid coiling, since DC switching can create damaging spikes.
- Keep all wires as short as possible.

**Refer to the PowerOptimal website for the following:**

<table id="bkmrk-elon%C2%AE-smart-user-man"><tr><td>**![img-005.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/lqvimg-005.png)Elon® Smart User Manual**

</td><td>[**www.poweroptimal.com/manuals**](http://www.poweroptimal.com/manuals)

</td></tr><tr><td>![img-006.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/cmYimg-006.png)**Training videos for installers**

</td><td>[**www.poweroptimal.com/training**](http://www.poweroptimal.com/training)

</td></tr></table>

# <a id="bkmrk--12"></a>Table of Contents

[Table of Contents 3](#bkmrk--12)

[1. Required tools 5](#bkmrk--13)

[2. Basic wiring diagram 6](#bkmrk--14)

[3. Solar PV array installation 7](#bkmrk--18)

[4. Elon® Smart installation 9](#bkmrk--20)

[A. Inserting the Elon Smart unit into the geyser 9](#bkmrk--21)

[B. Preparing and wiring the AC disconnect switch to the Elon Smart 9](#bkmrk--24)

[C. Preparing and wiring the DC disconnect switch to the Elon Smart Thermostat 13](#bkmrk--30)

[D. Final insertion, testing and closing the cover 13](#bkmrk--31)

[E. Configuring the Elon Smart Thermostat using the Elon Smart App 14](#bkmrk--32)

[F. Applying warning labels and QR code label 17](#bkmrk--49)

[Appendix A. List of Alarms and How to Resolve Them 19](#bkmrk--52)

[Appendix B. Basic Troubleshooting Guide for Electricians 21](#bkmrk--57)

[Appendix C. Solar yield 23](#bkmrk--60)

[C1. Solar irradiance levels 23](#bkmrk--61)

[C2. Geographic features 24](#bkmrk--63)

[C3. Azimuth / horizontal angle 24](#bkmrk--64)

[C4. Inclination or tilt angle 24](#bkmrk--65)

[C5. Shading 24](#bkmrk--66)

[C6. Ambient temperature 25](#bkmrk--67)

[C7. Minimum distance from roof edges 25](#bkmrk--68)

[Appendix D. Deciding on Size of Solar Array 26](#bkmrk--69)

[Appendix E. PV array and geyser (water heater) element matching 30](#bkmrk--72)

[Appendix F. Technical Specification Summary: Elon® Smart 31](#bkmrk--73)

[Appendix G. Surge Protection Device (SPD) Recommendations 32](#bkmrk--74)

[G1. SANS 10142-1 The wiring of premises Part 1: Low-voltage installations 32](#bkmrk--75)

[G2. SANS 60364-7-712 (2018) Low Voltage Electrical Installations: Requirements for special installations or locations – Solar photovoltaic (PV) power supply systems 33](#bkmrk--78)

[Appendix H. IEC/SANS and EMC Test Certificates: Elon® Smart 36](#bkmrk--80)

[Appendix I. Warranty 39](#bkmrk--84)

[Appendix J. Terminology 40](#bkmrk--85)

[Notes 41](#bkmrk--86)

# <a id="bkmrk--13"></a>1. Required tools

The following tools are required for the installation. Use insulated tools wherever applicable.

- Solar modules (mounting) - *please refer to solar module / mounting installation instructions – the below is only a guideline*:
    - Cordless screwdriver with bits
    - Drill
    - Set of drill bits (wood, steel, stone)
    - Set of screwdrivers
    - Set of Allen (hex) keys
    - Tape measure
    - Grinder (tile roof installations)
    - Permanent marker
    - Chalk
    - Hammer
- Solar modules (electrical):
    - AC/DC Clamp meter
    - Side-cutting pliers
    - Screwdriver set
    - Crimping tool
    - 4 mm² wire (double insulated) (or other size as determined by solar PV voltage and wire length)
    - Cable ties
- Elon Smart - *the following additional tools*:
    - Insulated No. 2 Phillips or Pozidriv screwdriver
    - Insulated 5mm flat screwdriver
    - Wire Stripper for 1.5 -6mm wire
    - Wire Cutter for 1.5 -6mm wire
    - Cell phone with Elon Smart app installed
    - No. 8 spanner or socket for geyser earth stud

# <a id="bkmrk--14"></a>2. Basic wiring diagram

**Note 1:** Both AC &amp; DC circuit breakers or isolators must be installed **within 1.5m of the geyser** (water heater), line of sight.

**Note 2**: **Surge Protection Device (SPD)** only required in higher lightning strike density areas (such as parts of Gauteng and Mpumalanga), or where the DC cables are long. See **Appendix F**.

![img-007.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Vpgimg-007.png)

**Figure 2.1 Basic wiring diagram for the Elon Smart.**

# <a id="bkmrk--17"></a>

# <a id="bkmrk--18"></a>3. Solar PV array installation

Modules should only be installed by a **trained solar PV installation technician**. Array **position and orientation have a major impact on power production** (see Appendix B).

Review the instructions from your solar PV module supplier / manufacturer on installation.

![img-008.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Fdcimg-008.png)

**Please note:** Your installer should comply with SANS 10142-1 (Standard for low voltage installations) and SANS 60364-7-712 when doing your solar PV installation. If they are not well familiar with these standards, you should look for a different solar PV installer.

SAPVIA (South African Photovoltaic Industry Association) has made available an excellent guide to solar PV installations. See:

[https://pvgreencard.co.za/wp-content/uploads/‌Solar%20PV%20Guidelines‌%20-%20Digital%20Spread%20High-res.pdf](https://pvgreencard.co.za/wp-content/uploads/Solar%20PV%20Guidelines%20-%20Digital%20Spread%20High-res.pdf)

**NB: Refer to Appendices C &amp; D for guidelines on selecting the right size solar PV array for the user requirements, and for correctly matching the solar PV array and the geyser element.**

The below installation steps are a **general guide only** – compliance with the abovementioned standards is **compulsory**.

1. A critical starting point is **safety gear**: ensure that all installers wear a helmet and insulated safety gloves, as well as fall protection safety gear that is securely fixed to anchor points if work will be done on a roof or elevated area.
2. The solar PV array should only consist of one string of 2 to 5 modules in series, or two parallel strings 2 to 5 modules each. **Do not exceed the DC voltage or current ratings of the Elon® Smart (230V DC and 15A DC) under any circumstances**.
3. Attach bracket / mounting structure to roof. Use mounting structure recommended by solar module supplier for roof type and size of solar modules.
4. Fix the solar PV modules to the mounting structure and connect the module cables to each other.
5. If practical, cover the modules to ensure that there is no potential for electric shock whilst installing the system.
6. Ground the mounting structure only.
7. Install the wiring from the solar PV array to the Elon® Smart unit in the ceiling space. Ensure circuit breakers / isolators are in the “Open” position. Installation of a Surge Protective Device (SPD) between the solar PV array and the Elon® Smart is required in high lightning strike areas, such as parts of Gauteng and Mpumalanga. See **Appendix F** for more information.
8. **Last step** is to connect the array to the rest of the wiring, making sure that both the positive and negative wires are fully isolated from ground and keeping circuit breakers / isolators in the “Open” position.

**Note: no separate earth spike** is required for Elon solar PV installations. That is because the Elon never disconnects the AC supply to the house and does not interfere with the existing earthing arrangement.

**Some “DO’s &amp; DON’T’s” when installing solar PV arrays:**

*Your solar PV installer should not make any of these basic mistakes, but they are listed here just in case.*

- DO earth the PV array structure.
- DO isolate the wires from the PV array structure.
- DO twist the DC cables together if practical.
- DON’T use different sizes, types or specifications of modules together in the same string or array.
- DON’T install solar arrays where they will be partially shaded during any season of the year if it can be avoided at all.
- DO install the arrays so that there is space for inspection or maintenance when needed.
- DO use cabling of the correct size for your solar array.
- DON’T install the solar array flush with your rooftop. Use struts / brackets that ensure an unrestricted **air gap of at least 40 mm** between the roof and the modules.
- DON’T walk on the modules.
- DO ensure that connectors are kept clean and away from water.
- DON’T leave exposed modules in short circuit.
- DO ensure that all connectors are securely fastened.
- DON’T exceed the voltage ratings of any components.
- DO properly route and secure all cables.
- DON’T coil cables.

# <a id="bkmrk--20"></a>4. Elon® Smart installation

**A note on poor geyser installations**

*Poor geyser installations can cause excessive heat loss, which increases electricity cost with no benefit. Check for the following:*

- There should be lagging (insulation) installed on *at least* the first meter of the hot water outlet pipe and the cold water inlet pipe.
- If the hot water outlet pipe is routed upwards from the geyser, a U-bend heat trap must be installed, otherwise natural hot water convection (circulation) will cause excessive heat loss from the geyser
- The geyser itself should have good quality insulation. (All new geysers since 2013 have had to comply with more stringent insulation requirements and should have good quality insulation.)
- If there is a solar thermal system still connected to the geyser, it is strongly recommended to uninstall it, or at the very least ensure that there are closed shut-off valves on both entering and exiting pipes.
- If there is a hot water circulation system installed in the house, good insulation along the whole pipe length is critical. Circulation times should also be kept to a minimum.
- It is NOT recommended to use a geyser timer together with the Elon 100 system.

## <a id="bkmrk--21"></a>A. Inserting the Elon Smart unit into the geyser

1. Make sure both the AC and the DC disconnect switches are in the **off** position.
2. Take off geyser cover
3. Take out existing thermostat
4. Insert the Elon Smart Thermostat stem at least 1/3<sup>rd</sup> of the way into the pocket (see **Figure 4.1**). Don’t insert it fully yet.

![img-009.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/f89img-009.png)

**Figure 4.1. STEP 4: Insert the Elon Smart Thermostat stem at least 1/3<sup>rd</sup> of the way into the thermostat pocket. Don’t insert it fully yet.**

## <a id="bkmrk--24"></a>

## B. Preparing and wiring the AC disconnect switch to the Elon Smart

1. Cut a 2.5mm² flexible cord for connecting Elon Smart to the AC disconnect switch (see **Figure 4.2**).
    1. The flexible cord has stranded wire which makes routing under the geyser cover much easier.
    2. It is not recommended to use solid 2.5mm² twin core + earth. If it is used take care, ensure wire lengths and routing do not put undue strain on the wiring causing it to be pulled out of the screw terminals when the geyser cover is put back.
    3. The cord needs an additional 15 cm to route under the geyser cover.
    4. The AC terminals on the Elon Smart can handle 1.5 – 4 mm² flexible cables, but at least 2.5 mm² is recommended.
2. Strip cord 15 cm to expose live neutral and earth wires.
3. Strip and crimp O-lug to earth.
4. Cut live and neutral wires to 8 cm and strip back the insulation by 6 mm.
5. Thread the cord through the geyser cover.
6. Connect cord to AC disconnect switch.
7. Connect the 2 Earth wires (green and yellow) coming out the right side of the Elon Smart and the earth from the AC cord to the geyser earth point (see **Figure 4.3**).

**![img-010.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/2xoimg-010.png)**

**Figure 4.2. STEPS 5 – 8: Preparation of AC cord to wire between AC disconnect switch and the Elon Smart thermostat.**

**Figure 4.3. STEP 11: Connect the two earth wires (green &amp; yellow) from the Elon Smart thermostat and the earth from the AC cord to the geyser earth point.**

1. Insert the Live and Neutral into the screw terminals labelled AC and tighten as per the following steps:
    1. The AC screw Terminals are located on the left of the Elon Smart Thermostat (see **Figure 4.4**).

![img-012.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/UeDimg-012.png)

**Figure 4.4. STEP 12: The AC screw terminals are located on the left of the Elon Smart Thermostat**

- 1. The wires are easier to insert if you rotate the Elon Smart 90° in the geyser socket. This gives a clear view of the screw terminals cage clamp (see **Figure 4.5**).

![img-013.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/nVGimg-013.png)

**Figure 4.5. STEP 12b: Rotate the Elon Smart 90° in the thermostat pocket to make the AC wires easier to insert.**

- 1. **Open the cage clamps fully by screwing counterclockwise before inserting the wires** to make sure the wire is inserted into the cage clamp and not the space below.
    2. Insert live (Brown or Red wire) into the right cage clamp marked **L.**
    3. Insert neutral (Blue or Black wire) into the left Cage clamp marked **N**.
    4. Make sure no strands are folded back when you insert the wires into the cage clamps before tightening.
    5. For 1.5mm² solid core wire, removing the insulation for 12mm, folding back, and squeezing with a set of pliers provides a more secure fit in the cage clamp when tightening (see **Figure 4.6**).
    6. Tug lightly on both wires to make sure they are tightened sufficiently.

**![img-014.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/6J9img-014.png)**

**Figure 4.6. STEP 12g: for solid core wire, fold back and squeeze the wire with a set of pliers to give the cage clamp a better grip.**

## <a id="bkmrk--30"></a>C. Preparing and wiring the DC disconnect switch to the Elon Smart Thermostat

1. Cut 2 pieces of solar double insulated wire for connecting Elon Smart to DC disconnect switch.
    1. The DC terminals of the Elon Smart can handle 2.5 – 6 mm² flexible cable, but 4mm² or 6mm² double insulated UV protected solar wire is recommended to minimise wiring losses.
    2. 4mm² or 6mm² stranded wire clamps better than 2.5mm² wire in the screw terminals.
    3. Bootlace ferrules can be used but are not required.
2. Connect one end of the wires to the DC disconnect switch.
3. Strip the other end of both wires to 10 mm.
4. Thread wires through geyser cover.
5. Insert the Solar Wires into the screw terminals labelled DC and tighten using a No. 2 Phillips screwdriver.
    1. The DC screw Terminals are located on the right of the device.
    2. **Open the cage clamps fully by screwing counterclockwise before inserting the wires** to make sure the wire is inserted into the cage clamp and not the space below.
    3. The wires are easier to insert if you rotate the Elon Smart 90° or 180° in the geyser socket. This gives a clear view of the screw terminals cage clamp.
    4. Insert **DC +** (positive) into the right cage clamp marked **+**
    5. Insert **DC -** (negative) into the left cage clamp marked **-**
    6. Make sure no strands are folded back when you insert the wires into the cage clamps before tightening.
    7. If the wires are stripped to the required 10mm, the wires can be inserted into the cage clamp up to the insulation before tightening.
    8. If using an electric screwdriver with a torque setting, tighten to 1.2 Nm.
6. Give the wires a light tug to make sure they are tightened securely.

## <a id="bkmrk--31"></a>D. Final insertion, testing and closing the cover

1. Press the Elon Smart thermostat into the Element making sure the blade terminals at the bottom fully engage with the element. It should press in quite firmly.
2. On new geysers with a standard double recess Kwikot end plate the Elon Smart thermostat should fit flush to the plate.
3. Turn on the DC disconnect switch.
4. Verify DC is present on the DC screw terminals (see **Figure A1** in Appendix A).
    1. Take care as the screws of the screw terminals are live;
    2. Verify DC polarity is correct.
5. Turn on the AC disconnect switch.
6. Verify AC is present on the AC screw terminals (see **Figure A2** in Appendix A).
7. Turn off the AC and DC disconnect switches.
8. Scan the QR code of the Elon Smart thermostat with the Elon Smart app before closing the cover.

## <a id="bkmrk--32"></a>E. Configuring the Elon Smart Thermostat using the Elon Smart App

1. <a id="bkmrk--33"></a>**Install the Elon Smart app** on your smart phone by searching for “Elon Smart Water” in the Google Play Store (Android) or Apple App Store (iPhone). Alternatively, scan one of the QR codes provided below using your phone camera.<a id="bkmrk--34"></a>

**NOTE:** if you have already installed the app on a previous occasion, please check that you have the latest version of the app by visiting the app page in your phone’s app store and tapping on “Update” if you don’t have the latest version. For convenience, you can scan one of the below QR codes to go to the app page in your app store.

**Elon Smart App**

**for iPhone:**

**Apple App Store**

**Elon Smart App for Android:**

**Google Play Store**

![img-015.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/WYLimg-015.png)![img-016.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/VNWimg-016.png)

<a id="bkmrk--36"></a>**Scan this QR code with your Android phone Scan this QR code with your iPhone to**

**to install the app from the Google Play Store install the app from the Apple App Store**

1. Once installed the application should display the startup screen (**Figure 4.7**)

![img-017.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/g6gimg-017.png)![img-018.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/NMiimg-018.png) ![img-019.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/DTVimg-019.png)

**Figure 4.7 Start-up screen Figure 4.8 Scanning screen Figure 4.9 Thermostat added**

1. **![img-020.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/boEimg-020.png)**Wait for the “App is authenticated” message to appear at the bottom of the screen.
2. Tap the **(+) button** on the bottom right to add the Smart thermostat.
3. The app will display the scanning screen called “**Add Thermostat**” (**Figure 4.8**). Scan the QR code by placing it horizontal and centred on the screen. (If the code does not want to scan, try moving the phone closer and further from the QR code. Try rotating the phone into landscape mode.)
4. **![img-021.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/i3rimg-021.png)**The app should take you back to the main screen after the thermostat has been added (**Figure 4.9**).
5. <a id="bkmrk--38"></a>Tap the **Settings (gear) button** on the right of the newly added thermostat.
6. The application requests confirmation to switch to the Smart Thermostat’s hotspot (**Figure 4.10**).
7. Select “**CONNECT**”
8. The application should display the “**Thermostat Settings**” screen (**Figure 4.11**)
9. ![img-022.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/wOcimg-022.png)First configure the Wi-Fi network that the unit will use to connect to the server. Tap the “Wi-Fi Hotspot” item .
10. The application searches for the available networks and displays them in a list (**Figure 4.12**).

![img-023.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Iuwimg-023.png)![img-024.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/B7Fimg-024.png)

 ![img-025.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/V8oimg-025.png)

**Figure 4.10 Network change Figure 4.11 Settings screen Figure 4.12 Select Wi-Fi**

1. Tap on the Wi-Fi network you want the Smart Thermostat to use.
2. The application will ask for a password for the network you selected (**Figure 4.13**).
3. Enter the password and tap “**Test Connection**”.
4. If you entered the password correctly the application should take you back to the configuration screen and the network should be green.
5. ![img-026.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/qO5img-026.png)Next configure the address. <a id="bkmrk--41"></a>Tap the “**Installed Adress**” item.
6. The app should connect to the server and obtain a list of addresses corresponding to your GPS co-ordinates (**Figure 4.14**). (You might need to switch on your phone GPS and allow the app to use your location services.)
7. Select the correct address.
8. The app should take you back to the “**Thermostat Settings**” screen (**Figure 4.15**).
9. ![img-027.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/2gKimg-027.png)Go to the top field called “**Thermostat Label**” and enter a new name for the smart thermostat. This will be used to identify this smart thermostat or geyser in your app.
10. ![img-028.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/KL5img-028.png)Now set the <a id="bkmrk--42"></a>“**Target Solar Temperature**” and “**Target Grid Temperature**” set points. It is best for savings and optimal solar power usage to select a lower temperature set point for grid power than for solar power. **65 °C** on **Solar** and **50 °C** on **Grid** are good set points.

**![img-029.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/bpKimg-029.png)**![img-030.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/zJTimg-030.png) ![img-031.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/0z2img-031.png)

**Figure 4.13 Enter Wi-Fi password Figure 4.14 Select address Figure 4.15 Heating settings**

1. Next you can set the “**Heating Profile**” according to your preference (see **Figures 4.16 and 4.17**). Select how the household wishes to use the hot water generated by the Smart thermostat (**Table 4.1**). It is typically best to start with the “**Morning and Evening Shower**” profile.

![img-032.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/0LNimg-032.png)![img-033.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/xm1img-033.png)

**Figure 4.16 Heating Profile settings Figure 4.17 Select Heating Profile**

**Table 4.1 Heating Profile options**

<table id="bkmrk-heating-profile-opti"><tr><td>**Heating Profile option**

</td><td>**Solar power use**

</td><td>**Grid power use**

</td><td>**Comments**

</td></tr><tr><td>**Grid Only**

</td><td>Never

</td><td>Always

</td><td>Select this option if you don’t have any solar panels installed.

</td></tr><tr><td>**Solar Only**

</td><td>Always

</td><td>Never

</td><td>ONLY use solar power. NEVER use grid power.

</td></tr><tr><td>**Morning Shower**

</td><td>Always except for 3 am – 5 am

</td><td>3 am – 5 am

</td><td>Solar power will be used whenever available, and grid power will only be used early in the morning to boost water temperature to the Grid set point if the temperature is lower than that.

</td></tr><tr><td>**Evening Shower**

</td><td>Always except for 5 pm – 7 pm

</td><td>5 pm – 7 pm

</td><td>Solar power will be used whenever available, and grid power will only be used in the late afternoon to boost water temperature to the Grid set point if the temperature is lower than that.

</td></tr><tr><td>**Morning and Evening Shower**

</td><td>Always except for 3 am – 5 am &amp; 5 pm – 7 pm

</td><td>3 am – 5 am &amp;

5 pm – 7 pm

</td><td>Solar power will be used whenever available, and grid power will only be used in the early morning and late afternoon to boost water temperature to the Grid set point if the temperature is lower than that.

</td></tr><tr><td>**Holiday Mode**

</td><td>Off

</td><td>Off

</td><td>System switched off completely

</td></tr><tr><td>**Custom Profile**

</td><td>Whenever not in grid mode

</td><td>Custom

</td><td>Use the Custom Profile option to set your own grid heating timers.

</td></tr></table>

<a id="bkmrk--46"></a>![img-034.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/6vIimg-034.png)

**Figure 4.18 Standard Heating Profiles (solar in orange, grid in blue)**

1. **Custom grid heating profile settings**
    1. If you want to set your own times for when the water should be heated with grid power, select the “**Custom Profile**” heating profile (see Figure 4.19).
    2. ![img-035.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/rVUimg-035.png)If you have already configured some custom profiles, you can select the custom heating profile you wish to activate (see Figure 4.20).
    3. ![img-036.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Dpdimg-036.png)If you have not configured any custom grid heating profiles yet or want to add a custom profile, tap “**New Profile**”.
    4. You can also edit an existing profile by selecting that profile and tapping “**Edit Profile**”.
    5. Once you’re on the custom profile editing screen (see Figure 4.21), give your custom profile a name so you can easily select it in future.
    6. ![img-037.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/CMsimg-037.png)You can add time slots for grid heating for the different days of the week, as well as target water temperatures. Note that you can add multiple time slots in a single custom profile by tapping “**Add Additional Timer**”.
    7. ![img-038.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/x8gimg-038.png)Once done with setting up your custom grid heating profile, don’t forget to tap “**Save**”.

![img-039.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/FqJimg-039.png)![img-040.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/klJimg-040.png)![img-041.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/mKSimg-041.png)

**Fig 4.19 Select “Custom Profile” Fig 4.20 Choose a custom profile Fig 4.21 Set grid time slots**

1. If there are any problems with the installation, an alarm will display below the thermostat settings, indicated by a red exclamation mark (**!**). See Appendix A for a list of alarms and how to resolve them (if needed).
2. Once you have cleared all the issues, then no more alarms will be displayed on the configuration settings screen.

**Please note:** DO NOT install a separate timer on the AC side to try and regulate mains power use. Use only the Elon Smart app to control mains power use. If you install a second timer, it will work at cross-purposes with the Elon and you will reduce performance and hot water availability.

## ![img-042.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Svcimg-042.png)F. How to delete a smart geyser from the app

***To delete a smart geyser from the app, tap and hold on the device that you want to delete on the home screen.***

A prompt will pop up for you to confirm whether you want to delete the device, as shown on the screenshot to the right.

## <a id="bkmrk--49"></a>

## G. How to view app and device software versions

To see the current version of the app and the current versions of all software on the Elon Smart Thermostat, tap on the hamburger menu ≡ in the top right of the home screen and then tap “**About**”. The left tab shows the mobile phone app version, whilst the right tab shows the device software versions.

![img-043.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/w3Zimg-043.png)![img-044.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/M5Cimg-044.png)

## H. Applying warning labels and QR code label

1. Attach labels included with the Elon Smart (see **Figure 4.16** below):
    1. Attach "Dual Supply" labels (a) to the AC isolator and the DC circuit breaker (or isolator).
    2. Attach "Warning – Photovoltaic Power Source" label (b) to the DC wiring conduit in a clearly visible position.
    3. Attach “Warning – disconnect supply circuits” label (c) to **outside of geyser end cover**.
    4. Attach Elon Smart QR code label (d) to the inside of the house’s DB board.

![img-045.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/gGVimg-045.png)

**Figure 4.16. Labels included with the Elon Smart**

**Final step: hand over the Quick Start User Guide (included in the box) to the household (or leave it in a prominent place for them to find such as the kitchen counter).**

# <a id="bkmrk--52"></a>Appendix A. Basic Troubleshooting for Users, List of Alarms and How to Resolve Them

Here is a flow diagram with basic troubleshooting steps for users. Always check that you have the **latest version of the app** by going to the “Elon Smart Water” app in your app store.

![img-046.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/vY4img-046.png)

![img-047.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Q0rimg-047.png)

![img-048.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/qkzimg-048.png)![img-049.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/hiJimg-049.png)

The Elon Smart has a helpful alarm system that detects and reports common issues. See the below list for the various alarms and how to resolve them.

<table id="bkmrk-idalarm-messagehow-t"><thead><tr><th>**ID**

</th><th>**Alarm message**

</th><th>**How to resolve the alarm**

</th></tr></thead><tbody><tr><td>0

</td><td>Element Faulty

</td><td>a. Check that the thermostat is inserted correctly.

b. If that does not clear the alarm, measure element resistance and replace if necessary.

</td></tr><tr><td>1

</td><td>Switch Failed

</td><td>Contact our help chat

</td></tr><tr><td>2

</td><td>DC Disconnect Failed

</td><td>Contact our help chat

</td></tr><tr><td>3

</td><td>No Power on AC Input

</td><td>This can be due to several reasons:

a. There is no AC power connected to the Elon Smart

b. AC power is off at the circuit breaker in the DB board or at the AC isolator close by the Elon Smart unit.

c. There is a power failure or loadshedding.

d. You have a geyser timer installed.

This alarm won’t prevent the Elon Smart unit from functioning and heating water with solar (DC) power as long as there is solar power available.

You can clear the alarm by switching the AC power on (where applicable), setting the Elon Smart heating policy to *Solar Only* (see Table 4.1) or you can leave it until AC power returns.

</td></tr><tr><td>4

</td><td>Measurement Failure

</td><td>Contact our help chat

</td></tr><tr><td>5

</td><td>Disconnected for Safety

</td><td>When there is a safety-related alarm condition, the Elon Smart will disconnect power from the geyser. To clear this alarm, you need to clear the other safety-related alarm(s).

</td></tr><tr><td>6

</td><td>Water Temperature Measurement Failure

</td><td>Contact our help chat

</td></tr><tr><td>7

</td><td>Ambient Temperature Exceeded

</td><td>a. Check the installation. If the geyser is installed in direct sunlight, see if you can provide shade to the geyser end space area where the Elon Smart is located.

b. Reduce temperature set point by 5 degrees.

c. Wait until temperatures cool down. The Elon Smart will start up again.

d. Contact our help chat if the above doesn’t clear the alarm.

</td></tr><tr><td>8

</td><td>DC Wiring Insulation Failure

</td><td>a. Check solar panels and DC wiring for insulation faults.

b. To operate the Elon Smart whilst the insulation fault has not been located and resolved, you can set the heating profile to *Grid Only* or switch off the DC disconnect switch.

</td></tr><tr><td>9

</td><td>Insulation Self-Test Failed

</td><td>a. Check earth wiring. Make sure both earth straps are connected securely to the geyser earth stud.

</td></tr><tr><td>10

</td><td>AC Wired to DC Input

</td><td>Wire AC to correct input (see Chapter 4).

</td></tr><tr><td>11

</td><td>DC Wired to AC Input

</td><td>Wire DC to correct input (see Chapter 4).

</td></tr><tr><td>12

</td><td>No Power on DC Input

</td><td>This can be due to several reasons:

a. There is no DC power connected to the Elon Smart

b. DC power is off at the DC disconnect switch close by the Elon Smart unit.

c. There is an issue with the DC wiring or solar PV installation.

d. It is extremely dark and overcast during daytime. (The alarm is not active when the sun is less than 15 degrees above the horizon.)

This alarm won’t prevent the Elon Smart unit from functioning and heating water with grid (AC) power as long as there is grid power available.

You can clear the alarm by:

- - 1. switching the DC power on (where applicable);
        2. setting the Elon Smart heating profile to *Grid Only*;
        3. leaving it until DC power returns; or
        4. inspect and fixing the DC wiring and/or solar PV installation.

</td></tr><tr><td>13

</td><td>DC Input Reversed

</td><td>The wiring on the Solar input has been installed incorrectly (in reverse). The DC+ (positive) wire has been connected to the DC- (negative) terminal on the Elon Smart and the DC- (negative) wire has been connected to the DC+ (positive) terminal on the Elon Smart. Swap the DC wires around (see Chapter 4).

</td></tr><tr><td>14

</td><td>Hot Connection

</td><td>Elon Smart not correctly inserted into geyser element. Switch off all power to the Elon Smart and re-seat (reinsert) the Elon Smart.

</td></tr><tr><td>15

</td><td>RTC Failed

</td><td>Contact our help chat

</td></tr><tr><td>16

</td><td>Power Unstable

</td><td>1. If it is intermittent or temporary and occurring during loadshedding or grid power failures, you can ignore this alarm.
2. If the alarm persists whilst grid power is available, check the following:
    1. Check that wiring to Elon Smart is properly connected and not loose.
    2. Check whether geyser circuit breaker in DB or the geyser’s AC isolator are faulty or wiring is not properly connected.
    3. If none of the above are present, then contact our help chat.

</td></tr><tr><td>17

</td><td>Server Not Available

</td><td>1. ![img-050.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/BW9img-050.png)Check that your home Wi-Fi network has internet connectivity.
2. Check the Elon Smart Wi-Fi settings on the thermostat settings screen (access by tapping the gear icon in the app when at home).
3. If your Wi-Fi router is far away from your geyser, the Wi-Fi signal might be too weak. This can be improved with a Wi-Fi extender or signal booster.

If none of the above works, try rebooting your Elon Smart by switching off the geyser circuit breaker on your house DB board at night for 2 minutes.

</td></tr></tbody></table>

# <a id="bkmrk--57"></a>Appendix B. Basic Troubleshooting Guide for Electricians

**NOTE:** This Troubleshooting Guide is intended for electricians and not general users.

**Things to Remember**

- After power up, the unit **runs a self-test that takes about 30 seconds**. Once the self-test passes the unit will engage the correct power source determined by the heating policy. If the water is below the temperature set point for the source (Grid or Solar), it will start heating water. You should hear a click when this happens.
- **Make sure that the wires are connected to the Elon Smart terminals securely** (do a tug test with AC &amp; DC power to the Elon Smart switched off) and check that the terminals have not been damaged (for example by overtightening).
- **If the two earth wires are not connected to the earth stud** the unit will fail the self-test and never start the heating process.
- **Check for any geyser timers** and bypass them completely or set them to “always on”.
- If you are having DC power supply issues, **check if the DC circuit breaker or isolator is faulty** by measuring the voltage across the DC circuit breaker or isolator whilst DC power is being supplied to the element. If there is a voltage drop across the disconnect switch, it is faulty and needs to be replaced. **Also check all DC fuses if installed.**
- **The unit will detect the following installation faults** and display them on the configuration screen. These will stop the unit from connecting power to the element until they are cleared:

1. DC + and DC – are reversed (reversed polarity);
2. The earth straps are not connected to the earth stud;
3. AC is connected to DC input;
4. There is a fault between the solar wiring and earth (insulation failure);
5. Element faulty (this may happen if you insert the unit so only a single spade connector makes contact with the element);
6. Unit component failure.

- **The unit will also warn the installer** if there is:

1. No power on the AC input. The alarm is not shown if heating policy *Solar Only* is selected.
2. No power on the DC input and it is daytime. The alarm is not shown if heating policy *Grid Only* is selected.

- For any Heating policy except *Grid Only*, solar power is normally engaged except for the periods listed in **Table 4.1**.
- If the unit has no grid power and engaging the element causes the DC voltage of the solar panels to drop below the voltage required to power the unit, the unit disconnects the element. If AC power is supplied, then the unit can run down to 0 V on DC. If the unit disconnects the element, it will stay disconnected for 2 minutes before connecting to the element again.
- If the unit is connected to the grid, it may draw a small amount of power (&lt;3W) from the grid even if *Solar Only* heating policy is selected.
- **How to switch on solar power to element**: Select *Solar Only* heating policy on the Thermostat Settings screen.
- **How to switch on mains power to element:** Select *Grid Only* heating policy on the Thermostat Settings screen.

**Troubleshooting Steps**

1. Open the Elon Smart app and go to the **Thermostat Settings** screen. Look at the alarms on the bottom of the screen and follow the instructions.
2. If you cannot access the unit through the application confirm that:
    1. The DC isolator is closed;
    2. The AC isolator is closed.
3. If you still cannot access the unit through the app, remove the geyser pocket cover and:
    1. Visually inspect the wiring ensuring that AC and DC wiring are still inserted into screw terminals;
    2. Check using a voltage meter that DC voltage is present on the DC screw terminals and polarity is not reversed (**Figure A1**);
    3. Check using a voltage meter that AC voltage is present on the AC screw terminals (**Figure A2**).

![img-051.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/zt3img-051.png)![img-052.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/U4zimg-052.png)

 <a id="bkmrk--59"></a>**Figure A1 Checking DC voltage Figure A2 Checking AC voltage**

# <a id="bkmrk--60"></a>Appendix C. Solar yield

**Note:** only basic information is provided here. Your solar PV installation design engineer or technician should advise on the best configuration for your specific location, roof structure, etc.

The yield produced by solar PV modules depends on several factors:

- Solar irradiance levels at your location (which varies with time of day, season and weather conditions)
- Geographic features at your location (e.g. mountains or buildings causing morning or afternoon shade)
- Azimuth and tilt of the modules
- Shading
- Ambient temperature (also influenced by wind)

## <a id="bkmrk--61"></a>C1. Solar irradiance levels

The map below shows the general solar irradiance levels (GHI or Global Horizontal Irradiance) in South Africa<sup><sup>[\[1\]](#bkmrk-crses-%28centre-for-re-1)</sup></sup>:

![img-053.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/oGTimg-053.png)

You can expect the following approximate energy generation from solar modules for various locations<sup><sup>[\[2\]](#bkmrk-urban-energy-support)</sup></sup>:

<table id="bkmrk-locationelectricity-"><tr><td>**Location**

</td><td>**Electricity generated kWh/kWp per year**

</td></tr><tr><td>Bloemfontein

</td><td>2055

</td></tr><tr><td>Cape Town

</td><td>1762

</td></tr><tr><td>Durban

</td><td>1570

</td></tr><tr><td>Johannesburg / Pretoria

</td><td>1871

</td></tr><tr><td>Mbombela

</td><td>1766

</td></tr><tr><td>Port Elizabeth

</td><td>1698

</td></tr><tr><td>Upington

</td><td>2075

</td></tr></table>

## <a id="bkmrk--63"></a>C2. Geographic features 

Major geographical features (such as hills or mountains) can reduce the total solar yield.![img-054.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/sb0img-054.png)

## <a id="bkmrk--64"></a>C3. Azimuth / horizontal angle 

The **azimuth** refers to the horizontal orientation of the modules – in the Southern Hemisphere, by how many degrees they are oriented away from north

**Due north** **is best** in the Southern hemisphere. Modules should preferably not be oriented more than 15º away from due north.

## <a id="bkmrk--65"></a>C4. Inclination or tilt angle 

The **tilt angle** refers to the vertical orientation of the modules – a rough guide is that the modules should be tilted at the site’s latitude. For example, Musina is 22º S, Pretoria &amp; Johannesburg are 26º S, Bloemfontein is 29º S, Durban is 30º S and Cape Town &amp; Gqeberha (Port Elizabeth) are 34º S.

To optimise winter performance, one can add 15º to the tilt angle. (**Note:** as long as you are within about 15º of the optimal latitude, the loss in efficiency is not substantial.)

## <a id="bkmrk--66"></a>C5. Shading

Solar modules lose a lot of efficiency if even a small part of the module is shaded. For example, just 3% shading can cause a 25% loss in power! Shaded cells on a module also causes hotspots, which will reduce module lifetime.

It is thus **important** to place the solar modules on a rooftop area that is **free from shading** for as much as possible of the day (and throughout the year).

## <a id="bkmrk--67"></a>C6. Ambient temperature

Solar PV modules’ performance decreases with increasing temperature. Wind will reduce the temperature of the solar array and will thus improve performance. Thus, it is important to install rooftop solar modules with an air gap of at least 40 mm between the modules and roof<sup><sup>[\[3\]](#bkmrk-d%E2%80%99orazio-m-et-al.-20)</sup></sup>.

## <a id="bkmrk--68"></a>C7. Minimum distance from roof edges

Your solar PV design engineer should prescribe minimum clearance from roof edges that should be maintained for your area based on climatic and wind conditions. Typically, a minimum clearance of 20 to 30 cm should be maintained.

# <a id="bkmrk--69"></a>Appendix D. Deciding on Size of Solar Array

***Terminology used***

![img-055.jpg](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/img-055.jpg)

Solar power is generated by solar **cells**, which are arranged in framed **modules**. The total set of solar PV modules installed is referred to as a solar PV **array<sup><sup>[\[4\]](#bkmrk-image-source%3A-http%3A%2F)</sup></sup>**.

The table below provides a basic guide to selecting the size of the solar PV array based on number of people in the household and/or hot water use. Minimum recommended size is 1 kW<sub>p</sub>. Read on for a more detailed guide.

<table id="bkmrk-solar-pv-array-size%28"><tr><td>**Solar PV array size**

**(kW<sub>p</sub>)**

</td><td>**Showers per day\***

</td><td>**50%+ of daily hot water use provided for how many people?**

</td><td>**How many people off-grid for hot water?**

</td><td>**Typical number of solar PV modules**

</td></tr><tr><td>**1 – 1.6**

</td><td>![img-056.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/8K7img-056.png)![img-057.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/0h7img-057.png)![img-058.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Dd2img-058.png)</td><td>![img-059.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/qcfimg-059.png)![img-060.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/nVPimg-060.png)![img-061.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/t3jimg-061.png)</td><td>![img-062.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/jdQimg-062.png)![img-063.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/38Limg-063.png)</td><td>**2 - 3 modules**

</td></tr><tr><td>**1.6 - 2**

</td><td>![img-064.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/F6Yimg-064.png)![img-065.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/KfHimg-065.png)![img-066.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/KfMimg-066.png)![img-067.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/5h7img-067.png)![img-068.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/tXvimg-068.png)![img-069.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/dOmimg-069.png)![img-070.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/nPMimg-070.png)</td><td>![img-071.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/tMIimg-071.png)![img-072.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/RYTimg-072.png)![img-073.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Uppimg-073.png)![img-074.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/t93img-074.png)</td><td>![img-075.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/pUhimg-075.png)![img-076.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Pznimg-076.png)![img-077.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/KP7img-077.png)</td><td>**3 - 4 modules**

</td></tr><tr><td>**2 - 3**

</td><td>![img-078.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/I3simg-078.png)![img-079.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/syximg-079.png)![img-080.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/RSPimg-080.png)</td><td>![img-081.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/khEimg-081.png)![img-082.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/3f4img-082.png)![img-083.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/iIaimg-083.png)![img-084.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/pw4img-084.png)![img-085.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Hbmimg-085.png)</td><td>![img-086.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/VQMimg-086.png)![img-087.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/EXUimg-087.png)![img-088.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/sVwimg-088.png)![img-089.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/e3fimg-089.png)</td><td>**4 - 5 modules**

</td></tr></table>

\* 6-minute showers at 40 °C with 8 litre/min (low-flow) showerheads

***TABLE D1. ANNUAL AVERAGE LITRES OF WATER HEATED PER DAY***

The below example table indicates the average number of litres of water per day that the system will heat from 15 to 60 °C over a year period for different solar array peak power ratings. (The amount of water heated will vary with weather conditions, by geographic location and by season. Water heated per day will be significantly lower in winter and significantly higher in summer. These numbers indicate heating capacity – i.e. if no hot water is used on a given day, there will be less water heated on that day. This is only an **approximate** guide.)

<table id="bkmrk-%C2%A0solar-%2B-elon%C2%AEannual"><thead><tr><th></th><th colspan="2">**Solar + Elon®**

</th><th colspan="16">**Annual average litres of water heated per day for X kW<sub>p</sub> installed solar capacity**

</th></tr><tr><th>**Location**

</th><th colspan="2">**kWh/kW<sub>p</sub>/yr**

</th><th>**0.8 kW<sub>p</sub>**

</th><th colspan="2">**1 kW<sub>p</sub>**

</th><th colspan="2">**1.2 kW<sub>p</sub>**

</th><th colspan="2">**1.4 kW<sub>p</sub>**

</th><th colspan="2">**1.6 kW<sub>p</sub>**

</th><th colspan="2">**1.8 kW<sub>p</sub>**

</th><th colspan="2">**2 kW<sub>p</sub>**

</th><th>**2.5 kW<sub>p</sub>**

</th><th>**3 kW<sub>p</sub>**

</th><th>**3.5 kW<sub>p</sub>**

</th></tr></thead><tbody><tr><td colspan="2">Bloemfontein

</td><td>1894

</td><td colspan="2">80

</td><td colspan="2">99

</td><td colspan="2">119

</td><td colspan="2">139

</td><td colspan="2">159

</td><td colspan="2">179

</td><td>199

</td><td>249

</td><td>298

</td><td>348

</td></tr><tr><td colspan="2">Cape Town

</td><td>1624

</td><td colspan="2">68

</td><td colspan="2">85

</td><td colspan="2">102

</td><td colspan="2">119

</td><td colspan="2">136

</td><td colspan="2">154

</td><td>171

</td><td>213

</td><td>256

</td><td>299

</td></tr><tr><td colspan="2">Durban

</td><td>1447

</td><td colspan="2">61

</td><td colspan="2">76

</td><td colspan="2">91

</td><td colspan="2">106

</td><td colspan="2">122

</td><td colspan="2">137

</td><td>152

</td><td>190

</td><td>228

</td><td>266

</td></tr><tr><td colspan="2">Jhb/Pretoria

</td><td>1724

</td><td colspan="2">72

</td><td colspan="2">91

</td><td colspan="2">109

</td><td colspan="2">127

</td><td colspan="2">145

</td><td colspan="2">163

</td><td>181

</td><td>226

</td><td>272

</td><td>317

</td></tr><tr><td colspan="2">Mbombela

</td><td>1627

</td><td colspan="2">68

</td><td colspan="2">85

</td><td colspan="2">103

</td><td colspan="2">120

</td><td colspan="2">137

</td><td colspan="2">154

</td><td>171

</td><td>214

</td><td>256

</td><td>299

</td></tr><tr><td colspan="2">Gqeberha (PE)

</td><td>1565

</td><td colspan="2">66

</td><td colspan="2">82

</td><td colspan="2">99

</td><td colspan="2">115

</td><td colspan="2">132

</td><td colspan="2">148

</td><td>164

</td><td>205

</td><td>247

</td><td>288

</td></tr><tr><td colspan="2">Upington

</td><td>1912

</td><td colspan="2">80

</td><td colspan="2">100

</td><td colspan="2">121

</td><td colspan="2">141

</td><td colspan="2">161

</td><td colspan="2">181

</td><td>201

</td><td>251

</td><td>301

</td><td>352

</td></tr><tr><td colspan="2">Saldanha

</td><td>1623

</td><td colspan="2">68

</td><td colspan="2">85

</td><td colspan="2">102

</td><td colspan="2">119

</td><td colspan="2">136

</td><td colspan="2">153

</td><td>170

</td><td>213

</td><td>256

</td><td>298

</td></tr></tbody></table>

**Example:**

For a **solar array of 1.2 kW<sub>p</sub>**, an installation in **Johannesburg** would yield about 1724 kWh/kW<sub>p</sub>/yr, or 1724 x 1.2 kW<sub>p</sub> = **2069 kWh/yr**. This would be sufficient to heat on average **109 litres of water per day**. For a family of 2 each using 80 litres of hot water per day, this would provide about 109 ÷ (80 x 2) or **68% of the annual hot water requirement**.

***TABLE D2. ANNUAL AVERAGE NUMBER OF SHOWERS PER DAY***

The below table indicates the average number of showers per day for which the system will supply hot water over a year period for different solar array peak power ratings. (The amount of water heated will vary with weather conditions, by geographic location and by season. Water heated per day will be significantly lower in winter and significantly higher in summer. These numbers indicate heating capacity – i.e. if no hot water is used on a given day, there will be less water heated on that day. This is only an approximate guide.)

<table id="bkmrk-%C2%A0solar-%2B-elon%C2%AEnumber"><tr><td></td><td>**Solar + Elon®**

</td><td colspan="9">**Number of showers per day (based on annual average) for X kW<sub>p</sub> installed solar capacity**

</td></tr><tr><td>**Location**

</td><td>**kWh/kW<sub>p</sub>/yr**

</td><td>**0.8 kW<sub>p</sub>**

</td><td>**1 kW<sub>p</sub>**

</td><td>**1.2 kW<sub>p</sub>**

</td><td>**1.4 kW<sub>p</sub>**

</td><td>**1.6 kW<sub>p</sub>**

</td><td>**1.8 kW<sub>p</sub>**

</td><td>**2 kW<sub>p</sub>**

</td><td>**2.5 kW<sub>p</sub>**

</td><td colspan="2">**3 kW<sub>p</sub>**

</td></tr><tr><td>Bloemfontein

</td><td>**1894**

</td><td>**2.4**

</td><td>**3.0**

</td><td>**3.6**

</td><td>**4.2**

</td><td>**4.8**

</td><td>**5.4**

</td><td>**6.0**

</td><td>**7.5**

</td><td colspan="2">**9.0**

</td></tr><tr><td>Cape Town

</td><td>**1624**

</td><td>**2.0**

</td><td>**2.6**

</td><td>**3.1**

</td><td>**3.6**

</td><td>**4.1**

</td><td>**4.6**

</td><td>**5.1**

</td><td>**6.4**

</td><td colspan="2">**7.7**

</td></tr><tr><td>Durban

</td><td>**1447**

</td><td>**1.8**

</td><td>**2.3**

</td><td>**2.7**

</td><td>**3.2**

</td><td>**3.6**

</td><td>**4.1**

</td><td>**4.6**

</td><td>**5.7**

</td><td colspan="2">**6.8**

</td></tr><tr><td>Jhb/Pretoria

</td><td>**1724**

</td><td>**2.2**

</td><td>**2.7**

</td><td>**3.3**

</td><td>**3.8**

</td><td>**4.3**

</td><td>**4.9**

</td><td>**5.4**

</td><td>**6.8**

</td><td colspan="2">**8.2**

</td></tr><tr><td>Mbombela

</td><td>**1627**

</td><td>**2.1**

</td><td>**2.6**

</td><td>**3.1**

</td><td>**3.6**

</td><td>**4.1**

</td><td>**4.6**

</td><td>**5.1**

</td><td>**6.4**

</td><td colspan="2">**7.7**

</td></tr><tr><td>Gqeberha (PE)

</td><td>**1565**

</td><td>**2.0**

</td><td>**2.5**

</td><td>**3.0**

</td><td>**3.5**

</td><td>**3.9**

</td><td>**4.4**

</td><td>**4.9**

</td><td>**6.2**

</td><td colspan="2">**7.4**

</td></tr><tr><td>Upington

</td><td>**1912**

</td><td>**2.4**

</td><td>**3.0**

</td><td>**3.6**

</td><td>**4.2**

</td><td>**4.8**

</td><td>**5.4**

</td><td>**6.0**

</td><td>**7.5**

</td><td colspan="2">**9.0**

</td></tr><tr><td>Saldanha

</td><td>**1623**

</td><td>**2.0**

</td><td>**2.6**

</td><td>**3.1**

</td><td>**3.6**

</td><td>**4.1**

</td><td>**4.6**

</td><td>**5.1**

</td><td>**6.4**

</td><td colspan="2">**7.7**

</td></tr></table>

The table is based on **6-minute** showers at **40 °C** and **8 litres/min** low flow showerheads. Old showerheads can use up to 15 litres/min and would substantially reduce the number of showers.

**Example:**

For a solar PV array of **2.5 kW<sub>p</sub>**, an installation in Johannesburg would yield about 1724 kWh/kW<sub>p</sub>/yr, or 1724 x 2.5 kW<sub>p</sub> = **4 310 kWh/yr**. This would be sufficient for about **6 to 7 showers per day**.

***TABLE D3. PERCENTAGE OF ANNUAL HOT WATER REQUIREMENT***

<a id="bkmrk--71"></a>The below example table indicates what % of the annual hot water requirement will on average be supplied by the system for **2 people each using 80 litres of hot (60 °C) water per day**. (The amount of water heated will vary with weather conditions, by geographic location and by season. Water heated per day will be significantly lower in winter and significantly higher in summer. These numbers indicate heating capacity – i.e. if no hot water is used on a given day, there will be less water heated on that day. This is only an **approximate** guide.)

<table id="bkmrk-solar-%2B-elon%C2%AEannual-"><tr><td></td><td>Solar + Elon®

</td><td colspan="9">**Annual average % of hot water requirement supplied for 2 people each using 80 litres of hot water per day for X kW<sub>p</sub> installed solar capacity**

</td><td></td></tr><tr><td>Location

</td><td>kWh/kW<sub>p</sub>/yr

</td><td>**0.8 kW<sub>p</sub>**

</td><td>**1 kW<sub>p</sub>**

</td><td>**1.2 kW<sub>p</sub>**

</td><td>**1.4 kW<sub>p</sub>**

</td><td>**1.6 kW<sub>p</sub>**

</td><td>**1.8 kW<sub>p</sub>**

</td><td>**2 kW<sub>p</sub>**

</td><td>**2.5 kW<sub>p</sub>**

</td><td>**3 kW<sub>p</sub>**

</td></tr><tr><td>Bloemfontein

</td><td>1894

</td><td>**50%**

</td><td>**62%**

</td><td>**75%**

</td><td>**87%**

</td><td>**99%**

</td><td>**112%**

</td><td>**124%**

</td><td>**155%**

</td><td>**187%**

</td></tr><tr><td>Cape Town

</td><td>1624

</td><td>**43%**

</td><td>**53%**

</td><td>**64%**

</td><td>**75%**

</td><td>**85%**

</td><td>**96%**

</td><td>**107%**

</td><td>**133%**

</td><td>**160%**

</td></tr><tr><td>Durban

</td><td>1447

</td><td>**38%**

</td><td>**47%**

</td><td>**57%**

</td><td>**66%**

</td><td>**76%**

</td><td>**85%**

</td><td>**95%**

</td><td>**119%**

</td><td>**142%**

</td></tr><tr><td>Jhb/Pretoria

</td><td>1724

</td><td>**45%**

</td><td>**57%**

</td><td>**68%**

</td><td>**79%**

</td><td>**91%**

</td><td>**102%**

</td><td>**113%**

</td><td>**142%**

</td><td>**170%**

</td></tr><tr><td>Nelspruit

</td><td>1627

</td><td>**43%**

</td><td>**53%**

</td><td>**64%**

</td><td>**75%**

</td><td>**85%**

</td><td>**96%**

</td><td>**107%**

</td><td>**134%**

</td><td>**160%**

</td></tr><tr><td>Gqeberha (PE)

</td><td>1565

</td><td>**41%**

</td><td>**51%**

</td><td>**62%**

</td><td>**72%**

</td><td>**82%**

</td><td>**92%**

</td><td>**103%**

</td><td>**128%**

</td><td>**154%**

</td></tr><tr><td>Upington

</td><td>1912

</td><td>**50%**

</td><td>**63%**

</td><td>**75%**

</td><td>**88%**

</td><td>**100%**

</td><td>**113%**

</td><td>**126%**

</td><td>**157%**

</td><td>**188%**

</td></tr><tr><td>Saldanha

</td><td>1623

</td><td>**43%**

</td><td>**53%**

</td><td>**64%**

</td><td>**75%**

</td><td>**85%**

</td><td>**96%**

</td><td>**107%**

</td><td>**133%**

</td><td>**160%**

</td></tr></table>

**Examples:**

An array of **1.2 kW<sub>p</sub>** will provide approximately **64%** of the annual hot water requirement for a family of **two people in Cape Town**.

An array of **2 kW<sub>p</sub>** will provide approximately 124% x (2 people / 4 people) = **62%** of the annual hot water requirement for a family of **four people in Bloemfontein**.

# <a id="bkmrk--72"></a>Appendix E. PV array and geyser (water heater) element matching

**It is important to match PV array specifications and heating elements for maximum power transfer efficiency**. See the below table for the recommended heating element power rating for different solar array sizes.

**Contact PowerOptimal** for advice on module-element matching if module properties are significantly different to typical values or **for advice on** **bifacial, high current &amp; high voltage modules**.

***TABLE E1. GUIDE: PV ARRAY AND GEYSER (WATER HEATER) ELEMENT MATCHING***

<table id="bkmrk-solar-pv-array-size%28-1"><tr><td>**Solar PV array size**

**(kW<sub>p</sub>)**

</td><td>**Best matching geyser element size**

**(kW)**

</td><td>**2<sup>nd</sup> choice geyser element size\***

**(kW)**

</td><td>**Geyser (water tank) size**

**(litres)**

</td></tr><tr><td>**1 – 1.6**

</td><td>**4**

</td><td>3

</td><td>100 - 200

</td></tr><tr><td>**1.6 – 2**

</td><td>**3**

</td><td>4 or 2

</td><td>100 - 200

</td></tr><tr><td>**2 – 3**

</td><td>**3**

</td><td>4

</td><td>150 – 300

</td></tr></table>

*\* Second choice element size would reduce efficiency by 10 – 20%.*

**DO NOT DEVIATE FROM THE RECOMMENDED MODULE-ELEMENT MATCHING CONFIGURATIONS WITHOUT CONSULTING POWEROPTIMAL.**

**Maximum** **allowed** solar PV array specifications at Standard Test Conditions (**STC**):

 **I<sub>sc</sub> &lt; 15A V<sub>oc</sub> &lt; 230V Power &lt; 3 kW<sub>p</sub>**

# <a id="bkmrk--73"></a>Appendix F. Technical Specification Summary: Elon® Smart

*Refer to the PowerOptimal website for the full Technical Specification* [www.poweroptimal.com/specifications](http://www.poweroptimal.com/specifications)

<table id="bkmrk-rated-input-voltage2"><tr><td>**Rated input voltage**

</td><td>230V AC, 230V DC

</td></tr><tr><td>**Rated input current**

</td><td>18A AC, 15A DC

</td></tr><tr><td>**Mains (AC) voltage range**

</td><td>230V +10% -15%

</td></tr><tr><td>**System power supply**

</td><td>Solar PV DC or 230V AC mains

</td></tr><tr><td>**Power consumption**

</td><td>3W on either AC or DC (solar) power

</td></tr><tr><td>**Solar voltage**

</td><td>30 – 230 V DC

</td></tr><tr><td>**Thermostat**

</td><td>Electronic thermostat with 0.5 °C accuracy

</td></tr><tr><td>**Safety**

</td><td>Electromechanical thermal cutout

</td></tr><tr><td>**Reverse polarity protection**

</td><td>For solar PV connections

</td></tr><tr><td>**Lightning protection**

</td><td>8 kA

</td></tr><tr><td>**Self-tests**

</td><td>Component failure, wiring failure, element failure, insulation failure, hot connections

</td></tr><tr><td>**Enclosure ingress protection rating**

</td><td>IP40

</td></tr><tr><td>**Annual energy production compared to inverter-based system**

</td><td>&gt; 90% when solar PV array and geyser element are matched correctly

</td></tr><tr><td>**Standards conformance**

</td><td>SANS 60730-1, SANS 60730-2-9, SANS / EN 301 489-1, SANS / EN 301 489-17, ICASA Type Approval, LoA from NRCS

</td></tr><tr><td>**Dimensions &amp; weight**

</td><td>23 x 12 x 11 cm, 0.3 kg. Box dimensions: 27.6 x 17.5 x 13.5 cm.

</td></tr><tr><td>**Patents**

</td><td>Granted: ZA 2019/02129, GB2583814B, ZA 2022/08516, EP 4100979, US 12,122,914, GB2618349

Pending: PCT/ZA2024/050065, GB2618349, ZA2024/08399, CH2023800381161, US 18/861,142, EP23723798.7, AU2023265634, ZA2024/08845

</td></tr><tr><td>**Registered Designs**

</td><td>ZA F2022/00962 (granted), F2022/00963 (granted)

</td></tr><tr><td>**Communications link**

</td><td>Wi-Fi Client, Wi-Fi Hotspot (2.4 GHz)

</td></tr><tr><td>**Measurements**

</td><td>AC energy, voltage, current (5%)

DC energy, voltage, current (5%)

Temperature: water &amp; ambient

</td></tr><tr><td>**Data logging**

</td><td>15-second data retained for 14 days

5-minute data retained for 366 days

</td></tr><tr><td>**Other features**

</td><td>Mobile app for installers and users

Full installation self-check

Remote firmware upgrades

50 000+ switching operations on thermostat

</td></tr></table>

It is important to match modules and heating elements for maximum power transfer efficiency. See the tables in **Appendix E** for the recommended heating element power rating for different solar module specifications and array configurations.

# <a id="bkmrk--74"></a>Appendix G. Surge Protection Device (SPD) Recommendations

This Appendix outlines under which circumstances a Surge Protection Device should be installed as part of a solar PV system installation such as the Elon® Smart.

## <a id="bkmrk--75"></a>G1. SANS 10142-1 The wiring of premises Part 1: Low-voltage installations

**Please note:** compliance with SANS 10142-1 is compulsory for all electrical installations as per the Occupational Health &amp; Safety Act.

**SANS 10142-1 states the following with regards to surge protection:**

***6.7.6 Surge protection***

*6.7.6.1 Surge protective devices (SPDs)* ***may be installed*** *to protect an installation against transient overvoltages and surge currents such as those due to switching operations or those induced by atmospheric discharges (lightning). NOTE A risk assessment may be performed in accordance with annex Q. The Installation of SPDs is necessary where structures are equipped with external lightning protection systems (LPS) as in accordance with SANS 10313.*

As can be seen above, surge protection is optional and based on a risk assessment as per Annex Q.

The risk assessment is as per the following table from SANS 10142-1 (2020):

![img-090.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Zo7img-090.png)

Note that the “Service Line” referred to above is the incoming (AC) line for the house.

Here is a lightning density map for South Africa as provided in SANS 10142-1:

![img-091.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Bgmimg-091.png)

## <a id="bkmrk--78"></a>G2. SANS 60364-7-712 (2018) Low Voltage Electrical Installations: Requirements for special installations or locations – Solar photovoltaic (PV) power supply systems

Section 712.443.5.101 of SANS 60364-7-712 requires a Surge Protection Device to be installed on the DC side of the installation where the length (**L**) of the DC cables (from PV array to Elon® Smart or inverter) exceeds the critical length **Lcrit** as follows:

A Surge Protection Device is required where **L ≥ Lcrit**

The critical length **Lcrit** depends on the type of PV installation and is calculated according to the following table:

<table id="bkmrk-type-of-installation"><tr><td>Type of installation

</td><td>Individual residential premises

</td><td>Terrestrial production plant

</td><td>Service / Industrial / Agricultural Buildings

</td></tr><tr><td>Lcrit (in meter)

</td><td>115/Ng

</td><td>200/Ng

</td><td>450/Ng

</td></tr></table>

where Ng = lightning strike density (number of strikes/km²/yr)

The length of DC cables **L** is the **sum** of:

- distances between the inverter(s) and the junction box(es), while observing that the lengths of cable located in the same conduit are counted only once, and
- distances between the junction box and the connection points of the photovoltaic modules forming the string, observing that the lengths of cable located in the same conduit are counted only once.

For the Elon® Smart, distance **L** is the length of DC cables from PV array to the Elon® Smart.

On the next page is a national lightning ground stroke density map for South Africa<sup><sup>[\[5\]](#bkmrk-evert-cr%2C-gijben-m.-)</sup></sup>.

From this map, the lightning strike density (Ng) range for major cities are as follows:

<table id="bkmrk-citylightning-strike"><thead><tr><th rowspan="2">**City**

</th><th rowspan="2">**Lightning strike density Ng (strikes/km²/yr)**

</th><th colspan="2">**Lcrit (m)**

</th></tr></thead><tbody><tr><td>**Individual residential premises**

</td><td>**Service / industrial / agricultural buildings**

</td></tr><tr><td>Cape Town

</td><td>0.02 to 4

</td><td>29

</td><td>113

</td></tr><tr><td>Stellenbosch

</td><td>0.02 to 4

</td><td>29

</td><td>113

</td></tr><tr><td>Worcester

</td><td>0.02 to 4

</td><td>29

</td><td>113

</td></tr><tr><td>George

</td><td>0.02 to 4

</td><td>29

</td><td>113

</td></tr><tr><td>Saldanha

</td><td>0.02 to 4

</td><td>29

</td><td>113

</td></tr><tr><td>Gqeberha (Port Elizabeth)

</td><td>0.02 to 4

</td><td>29

</td><td>113

</td></tr><tr><td>Buffalo City (East London)

</td><td>4 to 6

</td><td>19

</td><td>75

</td></tr><tr><td>King Williams Town

</td><td>4 to 6

</td><td>19

</td><td>75

</td></tr><tr><td>Beaufort-West

</td><td>4 to 6

</td><td>19

</td><td>75

</td></tr><tr><td>Musina

</td><td>4 to 6

</td><td>19

</td><td>75

</td></tr><tr><td>Britstown

</td><td>6 to 15

</td><td>8

</td><td>30

</td></tr><tr><td>Durban

</td><td>6 to 15

</td><td>8

</td><td>30

</td></tr><tr><td>Upington

</td><td>6 to 15

</td><td>8

</td><td>30

</td></tr><tr><td>Pietermaritzburg

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Greytown

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Polokwane

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Bloemfontein

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Queenstown

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Vryburg

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Mahikeng

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Mbombela (Nelspruit)

</td><td>15 to 21

</td><td>5

</td><td>21

</td></tr><tr><td>Kimberley

</td><td>21 to 27

</td><td>4

</td><td>16

</td></tr><tr><td>Pretoria

</td><td>21 to 27

</td><td>4

</td><td>16

</td></tr><tr><td>Vereeniging

</td><td>21 to 27

</td><td>4

</td><td>16

</td></tr><tr><td>Welkom

</td><td>21 to 27

</td><td>4

</td><td>16

</td></tr><tr><td>Johannesburg

</td><td>27 to 33

</td><td>3.5

</td><td>13

</td></tr><tr><td>Ermelo

</td><td>33 to 42

</td><td>2.5

</td><td>10

</td></tr><tr><td>Newcastle

</td><td>33 to 42

</td><td>2.5

</td><td>10

</td></tr></tbody></table>

![img-092.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/4Swimg-092.png)

From Evert &amp; Gijben (2017).

# <a id="bkmrk--80"></a>Appendix H. IEC/SANS and EMC Test Certificates: Elon® Smart

**![img-093.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Thbimg-093.png)**

**![img-094.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/thjimg-094.png)**

**![img-095.png](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/Benimg-095.png)**

# <a id="bkmrk--84"></a>Appendix I. Warranty

If the PowerOptimal Elon® Smart (“the Product”) is found to be defective, you will be entitled to a repair or replacement within 2 (two) year of the date of delivery of the Product to you. **Please keep your receipt as proof of purchase or register the Elon Smart online.** If you are a consumer as defined in the Consumer Protection Act No. 68 of 2008 (“the CPA”), you will be entitled to such remedies as are made available under the CPA in relation to the return of goods.

PowerOptimal will not have any liability or obligation to you where the Product has been subjected to abuse, misuse, improper use, improper testing, negligence, accident, alteration, tampering or repair by a third party.

To the maximum extent permitted by applicable law, in no event shall PowerOptimal be liable for any special, incidental, indirect, or consequential damages whatsoever, including, without limitation, damages for loss of business profits or business interruption, arising out of the use or inability to use this product.

**Please note that this unit must be installed by an electrical contractor registered with the Department of Labour.** Failure to do so may invalidate this warranty. Please keep the CoC (Certificate of Compliance) issued by the electrical contractor on completion of the installation.

Register your Elon Smart online to get an extended 5-year warranty here:

[https://poweroptimal.com/elon-extended-warranty/](https://poweroptimal.com/elon-extended-warranty/)

# <a id="bkmrk--85"></a>Appendix J. Terminology

AC Alternating Current – an electric current that reverses its direction many times a second at regular intervals, with voltage typically varying in the form of a sine wave.

CoC Certificate of Compliance – to be issued by the electrician installing your Elon® Smart system

CPA Consumer Protection Act No. 68 of 2008

DB Distribution board – the main electrical distribution board / panel in your home, containing circuit breakers and switches.

DC Direct Current – an electric current flowing in one direction only. Solar PV modules produce direct current electricity.

Geyser South African term for a water heater

IEC International Electrotechnical Commission

I<sub>mpp</sub> The solar module current at maximum power point (MPP). Manufacturers usually report two I<sub>mpp</sub> values: one at STC and one at NOCT.

kWh A derived unit of energy equal to 3.6 MJ (megajoules). The amount of energy used by a 1 kW electrical device over a period of 1 hour.

kW<sub>p</sub> or W<sub>p</sub> The peak power rating in kilowatt (kW) or watt (W) of a solar module or array – i.e., the output power achieved under full solar radiation. This is usually reported at STC and NOCT.

MPP Maximum power point. This is the point on a solar cell, module or array’s power or I-V (current-voltage) curve that has the highest power output.

NOCT Nominal Operating Cell Temperature (also sometimes referred to as NMOT or Nominal Module Operating Temperature). This refers to the temperature that open circuited solar PV modules will reach under conditions that more closely match actual field operational conditions than STC. The modules are tested at 800 W/m² simulated solar irradiance, 20 °C ambient temperature, 1 m/s wind velocity and open back side mounting. Depending on the quality of the cell / module design, the NOCT can reach anything from 33 to 58 °C<sup><sup>[\[6\]](#bkmrk-source%3A-http%3A%2F%2Fpvedu)</sup></sup>. Since solar PV cell power output reduces with increase in temperature, a lower NOCT is better.

PV Photovoltaic – referring to the production of electric current at the junction of two materials exposed to light.

SANS South African National Standards

STC Standard Test Conditions for solar cells – 1000 W/m² simulated solar irradiance and 25 °C solar cell temperature, and an air mass 1.5 spectrum (AM1.5).

V<sub>mpp</sub> The solar module voltage at maximum power point (MPP). Manufacturers usually report two V<sub>mpp</sub> values: one at STC and one at NOCT.

## <a id="bkmrk--86"></a>Notes

1. CRSES (Centre for Renewable and Sustainable Energy Studies). Website: [http://www.crses.sun.ac.za/files/research/publications/SolarGIS\_GHI\_South\_Africa\_width15cm\_300dpi.png](http://www.crses.sun.ac.za/files/research/publications/SolarGIS_GHI_South_Africa_width15cm_300dpi.png). Last accessed: 07/04/2017. [↑](#bkmrk-%5B1%5D)
2. Urban Energy Support. Website: [http://www.cityenergy.org.za/uploads/resource\_274.pdf](http://www.cityenergy.org.za/uploads/resource_274.pdf). Last accessed: 07/04/2017. [↑](#bkmrk-%5B2%5D)
3. D’Orazio M *et al*. 2013. Performance assessment of different roof integrated photovoltaic modules under Mediterranean Climate. [↑](#bkmrk-%5B3%5D)
4. Image source: [http://ohioline.osu.edu/factsheet/AEX-652-11](http://ohioline.osu.edu/factsheet/AEX-652-11). [↑](#bkmrk-%5B4%5D)
5. Evert CR, Gijben M. 2017. Official South African Lightning Ground Flash Density Map 2006 to 2017. [↑](#bkmrk-%5B5%5D)
6. Source: [http://pveducation.org/pvcdrom/modules/nominal-operating-cell-temperature](http://pveducation.org/pvcdrom/modules/nominal-operating-cell-temperature). [↑](#bkmrk-%5B6%5D)

# PowerOptimal Elon® Smart User Manual v1.19

![](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-wk6okdva.png)

<a id="bkmrk--2"></a>

<a id="bkmrk--4"></a>

![](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-gzpl8umq.png)

![](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-fugic9lo.png)

# Troubleshooting Guides

# Elon® Smart basic troubleshooting guide and alarms v1.6

## Water temperature is too low

Alarm icon ( ) showing in Elon Smart app

Yes

Contact a technician

Are there any alarms ( ) showing on the status screen?

Check the alarm message on the device status screen.

Water temperature is too high

Wait for 2 hours for hot water

No

Is the smart thermostat set to “Solar Only”?

Contact our help chat

Is water hot?

Resolved

Contact our help chat

Wait until power returns

\*Is geyser circuit breaker on at DB? \*Is the power on?

Press “heat with grid now” button.

Any Yes

\*Is it cloudy?

\* Have you used a lot of hot water?

\* Was there a power failure?

Yes

Wait (water is heating)

No

All No

Reported Issue:

Did the device switch to grid mode?

Is the status “Heating with solar”?

Reduce thermostat setting

Is water still too hot a day later?

Resolved

Contact our help chat

Yes

No

Elon® Smart basic troubleshooting guide

V1.6

How to use this guide

Select your issue in blue

Follow the steps indicated by the blue arrows until you reach a red or green final step.

Can you resolve the alarm yourself?

Resolved

Yes

No

Power source status greyed out

Does that resolve the issue?

Resolved

Contact our help chat

Yes

No

## Tap the Settings button in the app (within Wi-Fi range of your Elon Smart device). Update the Wi-Fi settings and save. Wait 5 minutes.

My Elon Smart status is not updating in the app

Yes

Contact our help chat

Fix your Wi-Fi network

Reported Issue:

Did you change your home Wi-Fi network name or password?

Resolved

Yes

No

No

Are you able to connect to the internet from your phone via the same Wi-Fi network?

Is the status updating now?

No

Yes

\*Is geyser circuit breaker on at DB?

\*Is the power on?

\*Is the sun shining?

Wait until power or sun returns

All Yes

No

Can’t connect to my Elon Smart with my phone (via the Settings button

or the “Thermostat settings” menu item)

Contact our help chat

\*Is geyser circuit breaker on at DB?

\*Is the power on?

\*Is the sun shining?

Wait until power or sun returns and check again

No

Yes

Can you connect now?

Resolved

Close and restart the Elon Smart app and try again.

Can you connect now?

Yes

No

Are you at home and within Wi-Fi range of your Elon Smart?

No

Wait until you get home or move closer to your Elon Smart device

Yes

## My Elon Smart won’t connect to my Wi-Fi network

Yes

Contact our help chat

Reported Issue:

Check your Wi-Fi router security settings (security mode). Is it set to WPA or WPA-PSK security?

Resolved

Yes

No

Can you connect now?

No

Change the security mode to WPA2.

Are you trying to connect to your router’s 5 GHz band? (The 5 GHz band is typically denoted by 5G or 5GHz at the end of the router name – for example “MYROUTER\_5G”)

No

Resolved

Yes

Can you connect now?

Connect to the router’s 2.4 GHz band (this is usually the router name without anything added to the end – for example “MYROUTER”)

Yes

Uninstall and reinstall the app, and reboot the Elon Smart by switching grid power off for 2 min at night.

Can you connect now?

Resolved

Yes

No

Contact our help chat

No

“Unhandled exception querying device” error

5 things to try:

Delete the geyser in the app and rescan the QR code;

Go to config screen and change heating policy;

Uninstall and reinstall the app;

Reboot the home Wi-Fi router

Switch off the geyser circuit breaker at the DB at night time, wait for 2 minutes and switch it on again (this will force the Elon Smart to reboot).

Did this clear the error?

Resolved

Contact our help chat

Yes

No

No

The Elon Smart unit might be out of range of your Wi-Fi network. If you can, reposition your Wi-Fi router closer to your geyser. Otherwise, you might need to get a Wi-Fi extender or booster.

Check that your Wi-Fi router is not set to only the 5 GHz band, but also the 2.4 GHz band.

Yes

Can you see your Wi-Fi network on the list of Wi-Fi networks in the app?

## AC not present alarm

Reported Issue:

For installers: how to configure the Elon Smart when no home Wi-Fi is available

You can configure the Elon Smart by connecting directly to it as follows:

Scan the QR code to add the Elon Smart to the app.

Tap the gear icon on the home screen or select “Thermostat settings” in the menu on the status screen to access the thermostat settings.

Configure the thermostat as described in the installation manual (set name, address, temperature set points, heating profile). Skip the Wi-Fi configuration.

The Elon Smart will function without a Wi-Fi connection after configured, but the status screen in the app will not update.

If you want to see the status screen (graphs and temperature) update, provide a mobile Wi-Fi hotspot on a second phone (not the one that you’re connecting to the Elon Smart with).

No

Resolved

Set heating profile to “Solar Only” to remove alarm

Is AC (grid) power to Elon Smart installed?

Yes

Yes to any question

Resolved

Wait until grid power returns or switch grid power on or set heating profile to “Solar Only”. The Elon Smart will use solar power if available and in solar mode, despite AC not present alarm.

No to all questions

Check the following:

Is there loadshedding?

Is there a power failure?

Is the geyser circuit breaker off at the house DB?

\[For technician:\] Is the AC isolator close by the geyser switched off?

Do you have a geyser timer installed?

Yes

Resolved

Remove all geyser timers (or switch to ‘grid power permanently on’) to avoid clashes with the Elon Smart.

Contact our help chat

Wait for a few hours to see if the alarm clears. If not, contact our Help Chat.

No

# Elon® Smart first line support checklist V1.7

**STEP 1. COLLECT INFORMATION FROM CUSTOMER**

<table id="bkmrk-customer-namecustome"><tr><td>**Customer Name**

</td><td colspan="7"></td></tr><tr><td>**Customer Address**

</td><td colspan="7"></td></tr><tr><td>**Date**

</td><td colspan="2"></td><td colspan="3">**Elon® serial no.**

</td><td colspan="2"></td></tr><tr><td>**What is the issue?**

</td><td colspan="7"></td></tr><tr><td>**How long have you been experiencing this issue?**

</td><td colspan="7"></td></tr><tr><td>**Have you had any power failures recently?**

</td><td colspan="7"></td></tr><tr><td>**Have you used more hot water than usual (such as having guests over), or at a different time than usual?**

</td><td colspan="7"></td></tr><tr><td>**Has the weather been cloudy or rainy in the last day or two?**

</td><td colspan="7"></td></tr><tr><td>**![](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-e9fc2ay9.png)Any alarms? (Indicated with an emphasised red exclamation mark on the home screen and with an alarm message on the status screen)**

</td><td>**Yes**

**🞏**

</td><td colspan="2">**No**

**🞏**

</td><td colspan="2">**Alarm message**

</td><td colspan="2"></td></tr><tr><td>**What heating profile is the Elon Smart thermostat set to?**

</td><td colspan="7"></td></tr><tr><td>**What are the temperature set points?**

</td><td>**Solar**

</td><td colspan="3">**°C**

</td><td colspan="2">**Grid**

</td><td>**°C**

</td></tr><tr><td>**What is the water temperature?**

</td><td colspan="7"></td></tr><tr><td>**Do you have the latest version of the Elon Smart app?**

</td><td colspan="7"></td></tr><tr><td colspan="2">**Position of geyser circuit breaker in DB (distribution board) (X)**

</td><td colspan="2">**On 🞏**

</td><td colspan="2">**Off 🞏**

</td><td colspan="2">**Don’t know 🞏**

</td></tr><tr><td>**Anything else to note?**

</td><td colspan="7"></td></tr></table>

**STEP 2: TROUBLESHOOTING**

**![A diagram of a flowchart

AI-generated content may be incorrect.](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-ryngnvjq.png)**

# PowerOptimal Elon® Smart Troubleshooting Guide for Electricians v1.7

**NOTE:** This Troubleshooting Guide is intended for electricians and not general users. Users should please refer to the User Manual, which can be found at [www.poweroptimal.com/manuals](http://www.poweroptimal.com/manuals). **Always check the PowerOptimal website for the latest version of this guide.**

<table id="bkmrk-unit-no.development-"><tr><td>**Unit no.**

</td><td></td><td colspan="2">**Development name**

</td><td colspan="2"></td><td>**Elon®**

**serial no.**

</td><td></td></tr><tr><td colspan="3">**Date**

</td><td colspan="2"></td><td>**Name: 1<sup>st</sup> level support person**

</td><td colspan="2"></td></tr><tr><td colspan="3">**Unit construction status (Works OR Final Completion)**

</td><td colspan="2"></td><td>**Resident name**

</td><td colspan="2"></td></tr><tr><td colspan="3">**Reported issue (customer)**

</td><td colspan="5"></td></tr><tr><td colspan="3">**Reported issue (Level 1 Support)**

</td><td colspan="5"></td></tr></table>

**Troubleshooting Steps**

<table id="bkmrk-no.actionresultunits"><tr><td>**No.**

</td><td colspan="2">**Action**

</td><td>**Result**

</td><td>**Units**

</td></tr><tr><td>1

</td><td colspan="2">Open the Elon Smart app. (Download the **Elon Smart Water** app from the Google Play or Apple app stores if you don’t have it installed on your phone. Make sure that you have the **latest version** of the app – you can check by searching “Elon Smart Water” in your app store and tapping “Update”.)

</td><td>**🞏**

</td><td></td></tr><tr><td>2

</td><td colspan="2">![](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-mmejiwtz.png)If you don’t have the specific thermostat in your device list, scan its QR code (on the house DB or on the thermostat itself) to add it by tapping the **+** button in the Elon Smart app.

</td><td>**🞏**

</td><td></td></tr><tr><td>3

</td><td colspan="2">![Single gear with solid fill](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-oxukki7g.png)Open the **Thermostat** **Settings** screen by tapping the Settings button

(the gear icon) to the right of the thermostat on the app status screen.

</td><td>**🞏**

</td><td></td></tr><tr><td>4

</td><td colspan="2">Check for any alarms at the bottom of the screen and rectify accordingly (See **list of alarms** at the end of this guide)

</td><td>**🞏**

</td><td></td></tr><tr><td rowspan="2">5

</td><td colspan="2" rowspan="2">If you cannot access the thermostat from the app, confirm that

1. the DC isolator / circuit breaker is closed (on);
2. the AC circuit breaker at DB and AC isolator are closed (on).

</td><td>**🞏**

</td><td>DC closed

</td></tr><tr><td>**🞏**

</td><td>AC closed

</td></tr><tr><td rowspan="3">6

</td><td colspan="2" rowspan="3">If you still cannot access the thermostat from the app, remove the geyser end cover and:

1. Visually inspect the wiring ensuring that AC and DC wiring are still inserted into screw terminals;
2. Check using a voltage meter that DC voltage is present on the DC screw terminals and polarity is not reversed (Figure 1);
3. ![A person connecting a cable to a device
    
    Description automatically generated](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-cypbc9ny.png)Check using a voltage meter that AC voltage is present on the AC screw terminals (Figure 2).

</td><td>**🞏**

</td><td>Wiring correct

</td></tr><tr><td></td><td>V DC &amp; correct polarity

</td></tr><tr><td>![A hand holding a blue box with black and red wires

Description automatically generated](http://docs.poweroptimal.com/uploads/images/gallery/2026-06/embedded-image-s4aldsuz.png)

</td></tr></table>