Electrical issue

[Webz]

Evey now and then, when there is a large electrical load, the ceiling lights will flicker and the voltage will drop to 10.1 volts on the panel in the front overhead cabinet. Then it bounces back to 12.6 volts. During the low voltage, the inverter switches to inverting. When the load drops, the inverter goes back to float charging.
Every month I check the house batteries, clean up the posts and add distilled water as required.
I'm thinking (which gets me in trouble) there's a continuity problem with the battery cables. I've seen cables corrode under the insulation. Would bad battery cables cause the problem I'm having? Or is it something else.
I'm open to any suggestions. TIA

[HarryStone]

When the inverter switches to inverting, it indicates that you lost 120VAC to the inverter, which may explain why the DC system voltage takes a big hit, because the inverter is now providing all your AC requirements. I'd be looking at the ATS for loose connections or damaged contacts, of course only with all the power disconnected.

[swduns]

- Usually the problem turns out to be something other than what you first suspected
- the problem could be an intermittent open in a battery, an intermittent inverter issue, a bad AC circuit breaker, a poor wire termination somewhere, the main 300a fuse breaking down, etc
- So if it were me, I would start at the batteries and check everything on the DC side and start at shore power & check every thing on the AC side
- I agree with the prior post that the AC side might be the source
- regarding under the insulation - on a DC cable under the insulation is just a large wire. unless the wire is broken in two under the insulation, if there were corrosion it shouldn't cause a problem. I've never seen corrosion under the insulation on a wire. It is possible that there could be corrosion at a connection point, for example where a wire is crimped into a lug at the end.
-corrosion = bad connection = heat if you have a bad connection that point should get hot. you could feel the connection points to look for heat.
- I'd look for a loose connection
- it could be the inverter. you could remove and bypass the inverter then send it to the vendors depot, e.g. Xantrex has 4 major depots, I've had them check mine and send it back no charge except shipping
- in industry we survey equipment with a heat gun, if you have a temperature thermometer scanner gun/tool you could scan the breakers and terminations for hot spot.
- the pedestal circuit breaker regularly cause trouble as they are not intended to be switches unless they are bought as SWD switching duty which you rarely see. The internal contacts get pitted and cause a poor connection.
just some thoughts




-

[Skip426]

At 10.1 volts of available power the inverter , shouldn't be trying to invert , it should be giving a low battery warning .
Inverter float charge should be higher than 12.6 volts ; 13>13.2 would be normal.
Have you had your batteries load tested ?
Disconnected them from each other and done a voltage test ?
JMHO:
The condition you describe , sounds more like the inverter's internal charging circuit is shutting down due to an overheat condition ( possibly from trying to charge a bad battery ) then restarting after a cool down period.