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Thread: Changing 3 phase electric DB to single phase. (Switchover etc)

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    Changing 3 phase electric DB to single phase. (Switchover etc)

    Short history. Electrical to the house were done in the 'old' days when electricity was still cheap. 3 Phase power were needed for the under tile heating system which has become redundant and VERY expensive to run.

    My first reaction (to myself) was WHY do you want to do it. Wanted to add Solar and/or Generator but cannot afford to add it to everything. I do not want extension cords. The process to switch over must be VERY simple. So my idea was to have options to 'cut and paste'.

    Biggest issue that I've had was to 'split' the neutral (BLACK) wire to be isolated by phase. What a mess, but I've done it and in the process numbered/marked and documented ALL the wires in the DB.

    So now I have 3 Neutral bars (Completely isolated from each other).

    I also now have 3 LIVE wires (completely isolated from each other) going to a) Outside buildings b) Heavy users like geysers, stove, water pump and aircon and c) plugs and lights in the house.

    Attached see the picture of the layout up to the circuit breakers.

    My request to the other DIY guys on the forum.

    What would you do extra (or not do). Any comments (positive or negative) are welcome.

    Thanks
    JanBez
    Attached Files Attached Files

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    Diamond Member Justloadit's Avatar
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    I just went trough a similar exercise about a month ago.

    The easiest, was to strip out all the breakers and marked akk the repective wires for later identification, left the main isolator in the board, as the main cable did not need to be moved.

    Created two lines of breakers, one line for heavy loads which do not require a ELU, geysers(which are on my PV solar geyser system), stove, aircon, and some lights which can be connected to the generator as well though a transfer switch, but not the solar inverter. My generator can power the whole house even if all the loads are on, including geysers and aircon.
    The second line was all the loads that the inverter would power through a ELU. Split the Neutrals in to two bus bars respectively.

    In the same DB, there is a transfer switch, generator/Eskom, and a transfer switch Inverter/Eskom (The reason for this switch is for maintenance purposes or in case the inverter fails or needs to be removed) each Eskom and inverter through a single pole isolator (in case any work required on the respective lines with out affecting the load).
    There is a separate DB for the inverter which has isolators to and from the inverter, and in which I placed the Surge arresters. Recommendations from other installers was to place the surge arresters before the inverter.

    Rewired the loads again to the circuit breakers - neatly. took about a day of work to complete.
    Victor - Knowledge is a blessing or a curse, your current circumstances make you decide!
    Solar pumping, Solar Geyser & Solar Security lighting solutions - www.microsolve.co.za

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    Janbez54 (04-Jul-21)

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    Thanks for the comment / advice. I really appreciate it. The part I am still missing is ....

    In the same DB, ............, and a transfer switch Inverter/Eskom as well as .... There is a separate DB for the inverter which has isolators to and from the inverter,

    Currently I am looking at inverters and size vs price vs specs. Some has 'switchovers', some can solar and grid charge etc. I really do not want to upgrade later. Rather wait, save some more money and then buy.

    The other potential issue that I have is that I want to make sure that my current system ( see attached file in original post) is correct. Do not want to expand on an system that can be done better.

    Thanks

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    Diamond Member Justloadit's Avatar
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    Here are some pics.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	InvSys.jpg 
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ID:	8249   Click image for larger version. 

Name:	Open_DB.jpg 
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ID:	8250  
    Victor - Knowledge is a blessing or a curse, your current circumstances make you decide!
    Solar pumping, Solar Geyser & Solar Security lighting solutions - www.microsolve.co.za

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    Something I have noticed with many inverter installations ... and I see it in these pics.

    The Input/Output wires between the inverter and the trunking ... The inspector I use to test installation regards those wires as exposed wiring ... so to prevent it I have been using 100 mm deep trunking to contain the wires ... It would be interested to hear everyones comment about it ... it pretty much the same a the short piece of wire you see at lighting points.
    Comments are based on opinion...not always facts....that's why people use an alias.

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