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PowerOptimal Elon® Smart Installation Manual v1.19

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img-003.pngPowerOptimal Elon® Smart Thermostat

Installation Manual

Version number: 1.19img-003.png

Version date: 2025/12/28

Enquiries: [email protected]

Address: 88 12th Avenue

Kleinmond

7195

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

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

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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:

    img-005.pngimg-005.pngElon® Smart User Manual

    www.poweroptimal.com/manuals

    img-006.pngimg-006.pngTraining videos for installers

    www.poweroptimal.com/training

    Table of Contents

    Table of Contents 3

    1. Required tools 5

    2. Basic wiring diagram 6

    3. Solar PV array installation 7

    4. Elon® Smart installation 9

    A. Inserting the Elon Smart unit into the geyser 9

    B. Preparing and wiring the AC disconnect switch to the Elon Smart 9

    C. Preparing and wiring the DC disconnect switch to the Elon Smart Thermostat 13

    D. Final insertion, testing and closing the cover 13

    E. Configuring the Elon Smart Thermostat using the Elon Smart App 14

    F. Applying warning labels and QR code label 17

    Appendix A. List of Alarms and How to Resolve Them 19

    Appendix B. Basic Troubleshooting Guide for Electricians 21

    Appendix C. Solar yield 23

    C1. Solar irradiance levels 23

    C2. Geographic features 24

    C3. Azimuth / horizontal angle 24

    C4. Inclination or tilt angle 24

    C5. Shading 24

    C6. Ambient temperature 25

    C7. Minimum distance from roof edges 25

    Appendix D. Deciding on Size of Solar Array 26

    Appendix E. PV array and geyser (water heater) element matching 30

    Appendix F. Technical Specification Summary: Elon® Smart 31

    Appendix G. Surge Protection Device (SPD) Recommendations 32

    G1. SANS 10142-1 The wiring of premises Part 1: Low-voltage installations 32

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

    Appendix H. IEC/SANS and EMC Test Certificates: Elon® Smart 36

    Appendix I. Warranty 39

    Appendix J. Terminology 40

    Notes 41

    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

    2. Basic wiring diagram

    Note 1: Both AC & 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.pngimg-007.png

    Figure 2.1 Basic wiring diagram for the Elon Smart.

    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

    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

    NB: Refer to Appendices C & 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 & 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.

    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. 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 1/3rd of the way into the pocket (see Figure 4.1). Don’t insert it fully yet.

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

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

      5.

      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.

        6. Strip cord 15 cm to expose live neutral and earth wires.

        7. Strip and crimp O-lug to earth.

        8. Cut live and neutral wires to 8 cm and strip back the insulation by 6 mm.

        9. Thread the cord through the geyser cover.

        10. Connect cord to AC disconnect switch.

        11. 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.pngimg-010.png

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

        img-011.png 

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

          12.

          Insert the Live and Neutral into the screw terminals labelled AC and tighten as per the following steps:

            a.

            The AC screw Terminals are located on the left of the Elon Smart Thermostat (see Figure 4.4).

            img-012.pngimg-012.png

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

              b.

                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.pngimg-013.png

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

                  c.

                    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.

                    d. Insert live (Brown or Red wire) into the right cage clamp marked L.

                    e. Insert neutral (Blue or Black wire) into the left Cage clamp marked N.

                    f. Make sure no strands are folded back when you insert the wires into the cage clamps before tightening.

                    g. 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).

                    h. Tug lightly on both wires to make sure they are tightened sufficiently.

                    img-014.pngimg-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.

                    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.

                    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.

                    E. Configuring the Elon Smart Thermostat using the Elon Smart App

                    1. 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.

                    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:img-015.png

                    For Android: Google Play Store

                    img-015.pngimg-016.png

                    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 Storeimg-016.png

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

                    img-017.pngimg-018.pngimg-019.pngimg-018.pngimg-017.png img-019.png

                    Figure 4.7 Left to Right: Start-up screen Figure 4.8screen, Scanning screen Figure 4.9screen, Thermostat added

                    1. img-020.pngWait for the “App is authenticated” message to appear at the bottom of the screen.
                    2. Tap the img-020.png (+) button on the bottom right to add the Smart thermostat.
                    3. The app will display the scanning screen called “Add Thermostat” (Figure 4.87). 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.pngThe app should take you back to the main screen after the thermostat has been added (Figure 4.97).
                    5. 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 4.108).
                    7. Select “CONNECT”
                    8. The application should display the “Thermostat Settings” screen (Figure 4.118)
                    9. img-022.pngimg-022.pngFirst 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 4.128).

                    img-023.pngimg-024.png

                    img-025.pngimg-025.pngimg-024.pngimg-023.png

                    Figure 4.108 Left to right: Network change Figure 4.11change; Settings screen Figure 4.12screen; 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 4.139).
                    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.pngimg-026.pngNext configure the address. 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 4.149). (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 4.159).
                    9. img-027.pngimg-027.pngGo 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.pngimg-028.pngNow set the “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.pngimg-031.pngimg-030.pngimg-029.pngimg-030.png img-031.png

                    Figure 4.139 Left to right: Enter Wi-Fi password Figure 4.14password; Select address Figure 4.15address; Heating settings

                    1. Next you can set the “Heating Profile” according to your preference (see FiguresFigure 4.16 and 4.1710). 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.pngimg-033.pngimg-033.pngimg-032.png

                    Figure 4.1610 Left to right: Heating Profile settings Figure 4.17settings; Select Heating Profile

                    Table 4.1 Heating Profile options

                    Heating Profile option

                    Solar power use

                    Grid power use

                    Comments

                    Grid Only

                    Never

                    Always

                    Select this option if you don’t have any solar panels installed.

                    Solar Only

                    Always

                    Never

                    ONLY use solar power. NEVER use grid power.

                    Morning Shower

                    Always except for 3 am – 5 am

                    3 am – 5 am

                    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.

                    Evening Shower

                    Always except for 5 pm – 7 pm

                    5 pm – 7 pm

                    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.

                    Morning and Evening Shower

                    Always except for 3 am – 5 am & 5 pm – 7 pm

                    3 am – 5 am &

                    5 pm – 7 pm

                    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.

                    Holiday Mode

                    Off

                    Off

                    System switched off completely

                    Custom Profile

                    Whenever not in grid mode

                    Custom

                    Use the Custom Profile option to set your own grid heating timers.

                    img-034.pngimg-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)11).
                      2. img-035.pngIf you have already configured some custom profiles, you can select the custom heating profile you wish to activate (see Figure 4.20)11).
                      3. img-036.pngimg-035.png If you have not configured any custom grid heating profiles yet or want to add a custom profile, tap “New Profile”.
                      4. img-036.png 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)11), give your custom profile a name so you can easily select it in future.
                      6. img-037.pngimg-037.pngYou 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.pngimg-038.pngOnce done with setting up your custom grid heating profile, don’t forget to tap “Save”.

                    img-039.pngimg-040.pngimg-041.pngimg-041.pngimg-040.pngimg-039.png

                    Fig 4.1911 Left to right: Select “Custom Profile” Fig 4.20; Choose a custom profile Fig 4.21profile; 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.pngF. 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.

                    img-042.png

                    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.pngimg-044.pngimg-043.pngimg-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.pngimg-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).

                     

                    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.pngimg-046.png

                    img-047.pngimg-047.png

                    img-048.pngimg-049.pngimg-048.pngimg-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.

                    ID

                    Alarm message

                    How to resolve the alarm

                    0

                    Element Faulty

                    a. Check that the thermostat is inserted correctly.

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

                    1

                    Switch Failed

                    Contact our help chat

                    2

                    DC Disconnect Failed

                    Contact our help chat

                    3

                    No Power on AC Input

                    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.

                    4

                    Measurement Failure

                    Contact our help chat

                    5

                    Disconnected for Safety

                    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). 

                    6

                    Water Temperature Measurement Failure

                    Contact our help chat 

                    7

                    Ambient Temperature Exceeded

                    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.

                    8

                    DC Wiring Insulation Failure

                    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.

                    9

                    Insulation Self-Test Failed

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

                    10

                    AC Wired to DC Input

                    Wire AC to correct input (see Chapter 4).

                    11

                    DC Wired to AC Input

                    Wire DC to correct input (see Chapter 4).

                    12

                    No Power on DC Input

                    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.

                    13

                    DC Input Reversed

                    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).

                    14

                    Hot Connection

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

                    15

                    RTC Failed

                    Contact our help chat

                    16

                    Power Unstable
                    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.

                    17

                    Server Not Available
                    1. img-050.pngCheck 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.

                    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 & 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 (<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.pngimg-052.pngimg-051.pngimg-052.png

                    Figure A1A Left to right: Checking DC voltage Figure A2voltage; Checking AC voltage

                    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)

                    C1. Solar irradiance levels

                    The map below shows the general solar irradiance levels (GHI or Global Horizontal Irradiance) in South Africa[1]:

                    img-053.pngimg-053.png

                    You can expect the following approximate energy generation from solar modules for various locations[2]:

                    Location

                    Electricity generated kWh/kWp per year

                    Bloemfontein

                    2055

                    Cape Town

                    1762

                    Durban

                    1570

                    Johannesburg / Pretoria

                    1871

                    Mbombela

                    1766

                    Port Elizabeth

                    1698

                    Upington

                    2075

                    C2. Geographic features

                    Major geographical features (such as hills or mountains) can reduce the total solar yield.img-054.pngimg-054.png

                    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.

                    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 & Johannesburg are 26º S, Bloemfontein is 29º S, Durban is 30º S and Cape Town & 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.)

                    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).

                    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[3].

                    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.

                    Appendix D. Deciding on Size of Solar Array

                    Terminology used

                    img-055.jpgimg-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[4].

                    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 kWp. Read on for a more detailed guide.

                    Solar PV array size

                    (kWp)

                    Showers per day*

                    50%+ of daily hot water use provided for how many people?

                    How many people off-grid for hot water?

                    Typical number of solar PV modules

                    1 – 1.6

                    		 img-056.pngimg-057.pngimg-058.pngimg-056.pngimg-057.pngimg-058.png img-059.pngimg-060.pngimg-061.pngimg-059.pngimg-060.pngimg-061.png img-062.pngimg-063.pngimg-062.pngimg-063.png

                    2 - 3 modules

                    1.6 - 2

                     

                    img-064.pngimg-065.pngimg-066.pngimg-067.pngimg-068.pngimg-069.pngimg-070.pngimg-064.pngimg-065.pngimg-066.pngimg-067.pngimg-068.pngimg-069.pngimg-070.png                    		 img-071.pngimg-072.pngimg-073.pngimg-074.pngimg-071.pngimg-072.pngimg-073.pngimg-074.png img-075.pngimg-076.pngimg-077.pngimg-075.pngimg-076.pngimg-077.png

                    3 - 4 modules

                    2 - 3

                    		 img-078.pngimg-079.pngimg-080.pngimg-078.pngimg-079.pngimg-080.png

                     

                    img-081.pngimg-082.pngimg-083.pngimg-084.pngimg-085.pngimg-081.pngimg-082.pngimg-083.pngimg-084.pngimg-085.png

                     

                    img-086.pngimg-087.pngimg-088.pngimg-089.pngimg-086.pngimg-087.pngimg-088.pngimg-089.png

                    4 - 5 modules

                    * 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.)

                     

                    Solar + Elon®

                    Annual average litres of water heated per day for X kWp installed solar capacity

                    Location

                    kWh/kWp/yr

                    0.8 kWp

                    1 kWp

                    1.2 kWp

                    1.4 kWp

                    1.6 kWp

                    1.8 kWp

                    2 kWp

                    2.5 kWp

                    3 kWp

                    3.5 kWp

                    Bloemfontein

                    1894

                    80

                    99

                    119

                    139

                    159

                    179

                    199

                    249

                    298

                    348

                    Cape Town

                    1624

                    68

                    85

                    102

                    119

                    136

                    154

                    171

                    213

                    256

                    299

                    Durban

                    1447

                    61

                    76

                    91

                    106

                    122

                    137

                    152

                    190

                    228

                    266

                    Jhb/Pretoria

                    1724

                    72

                    91

                    109

                    127

                    145

                    163

                    181

                    226

                    272

                    317

                    Mbombela

                    1627

                    68

                    85

                    103

                    120

                    137

                    154

                    171

                    214

                    256

                    299

                    Gqeberha (PE)

                    1565

                    66

                    82

                    99

                    115

                    132

                    148

                    164

                    205

                    247

                    288

                    Upington

                    1912

                    80

                    100

                    121

                    141

                    161

                    181

                    201

                    251

                    301

                    352

                    Saldanha

                    1623

                    68

                    85

                    102

                    119

                    136

                    153

                    170

                    213

                    256

                    298

                    Example:

                    For a solar array of 1.2 kWp, an installation in Johannesburg would yield about 1724 kWh/kWp/yr, or 1724 x 1.2 kWp = 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.)

                     

                    Solar + Elon®

                    Number of showers per day (based on annual average) for X kWp installed solar capacity

                    Location

                    kWh/kWp/yr

                    0.8 kWp

                    1 kWp

                    1.2 kWp

                    1.4 kWp

                    1.6 kWp

                    1.8 kWp

                    2 kWp

                    2.5 kWp

                    3 kWp

                    Bloemfontein

                    1894

                    2.4

                    3.0

                    3.6

                    4.2

                    4.8

                    5.4

                    6.0

                    7.5

                    9.0

                    Cape Town

                    1624

                    2.0

                    2.6

                    3.1

                    3.6

                    4.1

                    4.6

                    5.1

                    6.4

                    7.7

                    Durban

                    1447

                    1.8

                    2.3

                    2.7

                    3.2

                    3.6

                    4.1

                    4.6

                    5.7

                    6.8

                    Jhb/Pretoria

                    1724

                    2.2

                    2.7

                    3.3

                    3.8

                    4.3

                    4.9

                    5.4

                    6.8

                    8.2

                    Mbombela

                    1627

                    2.1

                    2.6

                    3.1

                    3.6

                    4.1

                    4.6

                    5.1

                    6.4

                    7.7

                    Gqeberha (PE)

                    1565

                    2.0

                    2.5

                    3.0

                    3.5

                    3.9

                    4.4

                    4.9

                    6.2

                    7.4

                    Upington

                    1912

                    2.4

                    3.0

                    3.6

                    4.2

                    4.8

                    5.4

                    6.0

                    7.5

                    9.0

                    Saldanha

                    1623

                    2.0

                    2.6

                    3.1

                    3.6

                    4.1

                    4.6

                    5.1

                    6.4

                    7.7

                    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 kWp, an installation in Johannesburg would yield about 1724 kWh/kWp/yr, or 1724 x 2.5 kWp = 4 310 kWh/yr. This would be sufficient for about 6 to 7 showers per day.

                    TABLE D3. PERCENTAGE OF ANNUAL HOT WATER REQUIREMENT

                    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.)

                     

                    Solar + Elon®

                    Annual average % of hot water requirement supplied for 2 people each using 80 litres of hot water per day for X kWp installed solar capacity

                    		  

                    Location

                    kWh/kWp/yr

                    0.8 kWp

                    1 kWp

                    1.2 kWp

                    1.4 kWp

                    1.6 kWp

                    1.8 kWp

                    2 kWp

                    2.5 kWp

                    3 kWp

                    Bloemfontein

                    1894

                    50%

                    62%

                    75%

                    87%

                    99%

                    112%

                    124%

                    155%

                    187%

                    Cape Town

                    1624

                    43%

                    53%

                    64%

                    75%

                    85%

                    96%

                    107%

                    133%

                    160%

                    Durban

                    1447

                    38%

                    47%

                    57%

                    66%

                    76%

                    85%

                    95%

                    119%

                    142%

                    Jhb/Pretoria

                    1724

                    45%

                    57%

                    68%

                    79%

                    91%

                    102%

                    113%

                    142%

                    170%

                    Nelspruit

                    1627

                    43%

                    53%

                    64%

                    75%

                    85%

                    96%

                    107%

                    134%

                    160%

                    Gqeberha (PE)

                    1565

                    41%

                    51%

                    62%

                    72%

                    82%

                    92%

                    103%

                    128%

                    154%

                    Upington

                    1912

                    50%

                    63%

                    75%

                    88%

                    100%

                    113%

                    126%

                    157%

                    188%

                    Saldanha

                    1623

                    43%

                    53%

                    64%

                    75%

                    85%

                    96%

                    107%

                    133%

                    160%

                    Examples:

                    An array of 1.2 kWp will provide approximately 64% of the annual hot water requirement for a family of two people in Cape Town.

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

                    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 & high voltage modules.

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

                    Solar PV array size

                    (kWp)

                    Best matching geyser element size

                    (kW)

                    2nd choice geyser element size*

                    (kW)

                    Geyser (water tank) size

                    (litres)

                    1 – 1.6

                    4

                    3

                    100 - 200

                    1.6 – 2

                    3

                    4 or 2

                    100 - 200

                    2 – 3

                    3

                    4

                    150 – 300

                    * 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):

                    Isc < 15A Voc < 230V Power < 3 kWp

                    Appendix F. Technical Specification Summary: Elon® Smart

                    Refer to the PowerOptimal website for the full Technical Specification www.poweroptimal.com/specifications

                    Rated input voltage

                    230V AC, 230V DC

                    Rated input current

                    18A AC, 15A DC

                    Mains (AC) voltage range

                    230V +10% -15%

                    System power supply

                    Solar PV DC or 230V AC mains

                    Power consumption

                    3W on either AC or DC (solar) power

                    Solar voltage

                    30 – 230 V DC

                    Thermostat

                    Electronic thermostat with 0.5 °C accuracy

                    Safety

                    Electromechanical thermal cutout

                    Reverse polarity protection

                    For solar PV connections

                    Lightning protection

                    8 kA

                    Self-tests

                    Component failure, wiring failure, element failure, insulation failure, hot connections

                    Enclosure ingress protection rating

                    IP40

                    Annual energy production compared to inverter-based system

                    > 90% when solar PV array and geyser element are matched correctly

                    Standards conformance

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

                    Dimensions & weight

                    23 x 12 x 11 cm, 0.3 kg. Box dimensions: 27.6 x 17.5 x 13.5 cm.

                    Patents

                    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

                    Registered Designs

                    ZA F2022/00962 (granted), F2022/00963 (granted)

                    Communications link

                    Wi-Fi Client, Wi-Fi Hotspot (2.4 GHz)

                    Measurements

                    AC energy, voltage, current (5%)

                    DC energy, voltage, current (5%)

                    Temperature: water & ambient

                    Data logging

                    15-second data retained for 14 days

                    5-minute data retained for 366 days

                    Other features

                    Mobile app for installers and users

                    Full installation self-check

                    Remote firmware upgrades

                    50 000+ switching operations on thermostat

                    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.

                    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.

                    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 & 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.pngimg-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.pngimg-091.png

                    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:

                    Type of installation

                    Individual residential premises

                    Terrestrial production plant

                    Service / Industrial / Agricultural Buildings

                    Lcrit (in meter)

                    115/Ng

                    200/Ng

                    450/Ng

                    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[5].

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

                    City

                    Lightning strike density Ng (strikes/km²/yr)

                    Lcrit (m)

                    Individual residential premises

                    Service / industrial / agricultural buildings

                    Cape Town

                    0.02 to 4

                    29

                    113

                    Stellenbosch

                    0.02 to 4

                    29

                    113

                    Worcester

                    0.02 to 4

                    29

                    113

                    George

                    0.02 to 4

                    29

                    113

                    Saldanha

                    0.02 to 4

                    29

                    113

                    Gqeberha (Port Elizabeth)

                    0.02 to 4

                    29

                    113

                    Buffalo City (East London)

                    4 to 6

                    19

                    75

                    King Williams Town

                    4 to 6

                    19

                    75

                    Beaufort-West

                    4 to 6

                    19

                    75

                    Musina

                    4 to 6

                    19

                    75

                    Britstown

                    6 to 15

                    8

                    30

                    Durban

                    6 to 15

                    8

                    30

                    Upington

                    6 to 15

                    8

                    30

                    Pietermaritzburg

                    15 to 21

                    5

                    21

                    Greytown

                    15 to 21

                    5

                    21

                    Polokwane

                    15 to 21

                    5

                    21

                    Bloemfontein

                    15 to 21

                    5

                    21

                    Queenstown

                    15 to 21

                    5

                    21

                    Vryburg

                    15 to 21

                    5

                    21

                    Mahikeng

                    15 to 21

                    5

                    21

                    Mbombela (Nelspruit)

                    15 to 21

                    5

                    21

                    Kimberley

                    21 to 27

                    4

                    16

                    Pretoria

                    21 to 27

                    4

                    16

                    Vereeniging

                    21 to 27

                    4

                    16

                    Welkom

                    21 to 27

                    4

                    16

                    Johannesburg

                    27 to 33

                    3.5

                    13

                    Ermelo

                    33 to 42

                    2.5

                    10

                    Newcastle

                    33 to 42

                    2.5

                    10

                    img-092.pngimg-092.png

                    From Evert & Gijben (2017).

                    Appendix H. IEC/SANS and EMC Test Certificates: Elon® Smart

                    img-093.pngimg-093.png

                    img-094.pngimg-094.png

                    img-095.pngimg-095.png

                    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/

                    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

                    Impp The solar module current at maximum power point (MPP). Manufacturers usually report two Impp 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.

                    kWp or Wp 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[6]. 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).

                    Vmpp The solar module voltage at maximum power point (MPP). Manufacturers usually report two Vmpp values: one at STC and one at NOCT.

                    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. Last accessed: 07/04/2017. ↑

                    2. Urban Energy Support. Website: http://www.cityenergy.org.za/uploads/resource_274.pdf. Last accessed: 07/04/2017. ↑

                    3. D’Orazio M et al. 2013. Performance assessment of different roof integrated photovoltaic modules under Mediterranean Climate. ↑

                    4. Image source: http://ohioline.osu.edu/factsheet/AEX-652-11. ↑

                    5. Evert CR, Gijben M. 2017. Official South African Lightning Ground Flash Density Map 2006 to 2017. ↑

                    6. Source: http://pveducation.org/pvcdrom/modules/nominal-operating-cell-temperature. ↑

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