Wiring array disconnect

I am mounting a combiner/disconnect on a ground mounted array and a non-fused disconnect on the house(SCHNEIDER ELECTRIC Switch Not Fusible Hd 600-Volt 30-Amp 3-pole Nema-3R HU361RB 600V).  My question is how is that 3 pole disconnect wired?  Positive, negative, and ground connected to each pole so when switch is flipped all three are disconnected?

Comments

  • Dave AngeliniDave Angelini Solar Expert Posts: 3,304 ✭✭✭✭
    Are you in North America? Totally against code to disconnect the ground. Also against code to disconnect the negative conductor.
    Be careful !  Electrocution is never fun!
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  • DaveBDaveB Solar Expert Posts: 46 ✭✭
    The Array is outputting DC, not AC.  Array is also required to have ground so PV panels would still be grounded.  So you are saying there would be only the positive DC wire that needs to be disconnected and the other 2 poles could be used to disconnect 2 other arrays?

  • EstragonEstragon Registered Users Posts: 1,545 ✭✭✭✭
    I'm confused (not unusual). If you connect ground though a 3 conductor disconnect, and flip the switch, how is the array still grounded?

    Assuming a negative ground system, the negative and ground would normally be made somewhere on the house side of the switch. If the switch breaks the negative, how is that held to ground potential? I have the array frame ground separate from the dc negative ground tie, but that's another can of worms.

    Normally, as I understand it, the ground and negative would not be fused, switched, or otherwise have an easy way of disconnecting. Only the positive would have means of disconnection by way of breakers, fuses, or switches. In other words, yes, in a normally wired system, a 3 pole disconnect could be used to interrupt circuits from 3 arrays. The ground and negative should then both be at ground potential on the house side of the switch. Breaking the positive at the switch should put + wire on the house side at close to ground as well.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
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  • EstragonEstragon Registered Users Posts: 1,545 ✭✭✭✭
    A question on that particular switch though, is it rated for DC? DC sustains arcs better than AC, and and AC rated switch operated under load may not fare well.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • DaveBDaveB Solar Expert Posts: 46 ✭✭
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