VintageRacer wrote:
Make sure your sub panel does not have neutral bonded to ground. It must separate neutral and ground, the transfer switch must switch both neutral and hot to the inverter, which must bond neutral and ground. Neutral is always bonded to ground at one point only, and that is the source of the power. Remember that GFCI - ground fault circuit interrupter - is a bit of a misnomer. The device does nothing with ground at all and can be installed in a circuit that does not have ground (such is code-allowed for protecting old 2 conductor wiring in old houses). It does trip if there is any difference between the current flowing in the hot conductor and the current flowing in the neutral conductor. Having neutral bonded in two places can create such a difference.
Brian
Brian, my Todd PS250 ATS in our Beaver Monterey is 17 years old. It still works, but the shore power contactor in it looks slightly off-color (burned?) on the outer plastic. I am considering replacing the PS250 with a manual transfer switch. But the manual transfer switches I've found switch only the hot wires, not the neutral. According to what you've written above, it wouldn't be acceptable if I were to simply connect all of the neutrals together (shore, generator, output). What's the deal here? Why does the neutral have to be switched?
