Expanding AC distribution panel

DrewE wrote:

One potential reason you may get different readings of continuity with a multimeter is that you checked with the leads reversed one time and the circuit has a semiconductor of some sort (a diode or transistor) that only conducts in one direction.

I think you're a little bit confused on the AC stuff. There should not be a connection between the AC neutral and chassis ground on the RV with the shore power cord disconnected; they are supposed to be entirely separate on an RV. If you do have a connection, that's a ground fault and should be fixed. When plugged in, you will see continuity there because the AC neutral and ground are bonded together at the main service panel.

I didn't say AC neutral and chassis ground have a full continuity connection "with shore power disconnected". While checking continuity ("with shore power connected") using a DMM the DMM started to beep very rapidly with one probe connected to AC neutral and the other prob connected to DC neg- chassis ground. (same rapid beep with probes in either direction.

One explanation is the DMM (set to ohms/beep) is detecting differences in potential (VOLTAGE) between a current-carrying conductor (NEUTRAL) and a non-current-carrying conductor (GROUND).

I think the only reason I mentioned it is because I added it to my continuity tests of the entire system, (with shore power connected and disconnected) which included disconnection / connection of 12VDC from the batteries. Chassis ground is one commonality between AC and DC however which are essentially separate electrical system types until you convert AC into DC.

It's been a while since i've installed PUD service panels and re-wired an entire RV (removed old alum. 2 wire upgrading the entire RV to copper three wire with hot-neutral-ground.

But I remember grounding using NEC codes which at the time there were differences grounding a RV vs a house. I think NEC has since changed some it's grounding codes for homes.

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DC systems existed prior to AC which has primarily replaced DC due to AC being able to travel cost effectively over longer distances, not requiring larger cabling.

I do remember reading about certain types of high voltage carrying systems DC is preferred over AC. IIRC some types of extremely high voltage system DC is sometimes preferred.

There are very high voltage current carrying systems that are DC. Various factors are involved such as cost, some systems it's more cost effect to use AC while others DC. But I'm not really up on all the details, I would need to find and re-read the article(s) again.

Anyway I'm currently am trying to figure out what size fuses to use and which wires should be together on the same fuse. I have an idea of which size fuse to use but I think I'm going to take a look at my neighbors RV to see what size fuses their RV is using.