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Thread: 4 pole Main Switch or even isolator

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    4 pole Main Switch or even isolator

    Hello

    So on inverters and all still.

    Can you use a 4 pole CB or a 4 pole Isolator but have it so that the first two poles is line and neutral for the grid and then the second two poles for the inverter line and neutral ?

    I can't think or see anything wrong about it but hoping to find out more.



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    Quote Originally Posted by Dylboy View Post
    Hello

    So on inverters and all still.

    Can you use a 4 pole CB or a 4 pole Isolator but have it so that the first two poles is line and neutral for the grid and then the second two poles for the inverter line and neutral ?

    I can't think or see anything wrong about it but hoping to find out more.



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    Cannot off hand think of a regulation that would prevent you from doing so
    Also cannot think of a reason that you would want to do so

    I would prefer to double units , one for grid and one for inverter output.
    When I install the inverter and battery i am going to want to test that when grid drops that the inverter and batteries maintain the load - I would want the load to stay on .
    Also with a PV inverter I would test that the PV switches off when I lose grid , if it is hybrid I would want to ensure that PV feeds the panels .

    If I have an inverter problem , I may want to leave grid on but drop the load to see if it is an intermittent trip problem that knocks the inverter off

    Basically saying I see reason for 2 x double pole - Struggling to think of a reason I would want 4 pole

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    I also can not think.

    I to have it done often with 4 double poles or 3 if there is space in main DB for a double pole feed to inverter.

    I am thinking 4 pole to use as a main switch. So if their is smoke or something funny the client can hit the main switch of both DBs and it will isolate all power in the enclosures... Albeit it the top of each main switch of course.

    But with it on the double poles etc can be used as you stated above which I do to but thinking just clients know a main switch kills all so thinking to implement it

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    Quote Originally Posted by GCE View Post
    Basically saying I see reason for 2 x double pole - Struggling to think of a reason I would want 4 pole
    Assuming the inverter disconnect is on the load side of the inverter - To have a single switch that disconnects all power to the electrical installation.
    The only live cables would be from the supplier to the disconnector and from the inverter to the disconnector.

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    Quote Originally Posted by Dave A View Post
    Assuming the inverter disconnect is on the load side of the inverter - To have a single switch that disconnects all power to the electrical installation.
    The only live cables would be from the supplier to the disconnector and from the inverter to the disconnector.
    Yes 100% that.

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    Quote Originally Posted by Dave A View Post
    Assuming the inverter disconnect is on the load side of the inverter - To have a single switch that disconnects all power to the electrical installation.
    The only live cables would be from the supplier to the disconnector and from the inverter to the disconnector.
    Think of a generator - You don't disconnect in and out with one 4 pole switch - Is the reason the essential DB needs to have visual indication that power is on . and that the DB is marked sub mains , fed from generator.

    What are you going to do with a 3 phase generator/ hybrid inverter

    I have found that as soon as PV and inverters come into play everybody overthinks it. It is the same principle as a generator or UPS install

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    This isn't my first exposure to the idea of a single main switch for both...

    We came across one installation where the person had used a 3 pole isolator.
    Being one pole short, they had put the supply neutral and the inverter load neutral onto the same pole.
    The owner couldn't understand why we thought this was a problem

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