I've just finished adding some wiring
that enables me to switch AC power coming to the boat between shore, an inverter
, or a small portable Honda generator
on the aft deck
. The power then goes through the AC panel to the various outlets and AC-powered equipment
as before. Of course, I have to make sure that I don't do something stupid like running the battery charger
from the inverter
or the water
heater from anything but shore power
. This arrangements works well when powering boat AC from shore or the small Honda
, but powering it from the inverter isn't working right and has me baffled.
Here's what happens: After tuning on the inverter, the "reverse polarity" indicator lights up, then if you switch on the main breaker it immediately trips. (Yes, i've checked oll the wiring
to make sure that hot and neutral weren't switched somewhere, and also tried purposely switching hot and neutral to see if it would make a difference - it did not)
Then I took a closer look at the AC panel and found that the main breaker is a 3-pole - 1 for the hot, 1 for the neutral (white), but the third one connects the ground bus-bar (green wires) to the neutral (white). I thought that on a boat, the green and white wires are supposed to remain separated and are only connected at the source - either the marina's distribution panel, or at the genset, etc. I experimented with removing the wire that connects green to white through the main breaker third pole, and then the inverter powers the panel as expected without tripping the breaker, but the reverse polarity indicator still lights up. The reverse polarity indicator is connected between the neutral (white) and the ground (green) bus. Although I could get the panel to work from the inverter by leaving this wire disconnected, I don't want to do that unless I understand why it was there in the first place.
Csn anyone give me some insight into this mystery?