Wiring the SPD

I have the Baby box breaker box, one 40 amp PV DC breaker and one 100 amp Dc converter breaker; three panels,
How do I wire in the protection device? (Midnight solar SPD)
One wire; green/ground and Neutral wire to frame ground, and one wire; line, to hot on breaker? is that correct?
I do have surge protection for the line voltage power, a 2 pole intermatic.
Instructions are geared to power grid applications as far as I could see.


  • BB.BB. Super Moderators, Administrators Posts: 32,813 admin
    Re: Wiring the SPD

    If I understand your question correctly... Yes, you have it wired correctly.

    You do not need to wire the SPD through a circuit breaker and could wire it directly, for example, to the battery bus:

    It is not required to have a circuit breaker or fuse in series with the SPD. The SPD has its own internal fusing.

    However, I would suggest not wiring directly to the battery bus but behind a DC breaker.

    Note, most breakers do not allow to wires to their single binding screw. You are supposed to use a pig tail and a wire nut to wire load (or solar panel in your case) to the SPD and another short wire from the wire nut to the breaker.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • OzzJimOzzJim Solar Expert Posts: 37
    Re: Wiring the SPD

    Thanks! I appreciate it.
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