Bought an old Class C - Electrical question?
Hi all- A friend of mine and I just bought an old 1978 Dodge Midas Class C motorhome to use on a property she just bought until the home is built. To be honest, the thing is a bit of a mess, but we'r...
Forum Discussion
There are all sorts of variations possible. Not infrequently the converter, DC load panel, and AC load panel are all in one unit. Sometimes DC and AC distribution are combined, with a separate converter. Probably sometimes a converter and DC are combined, with a separate AC panel.
Having some sort of a DC distribution panel is a good idea. Certainly all the DC circuits need to be properly fused somehow or another for safety, and having inline fuses helter-skelter is hard to keep track of and untidy and generally not best practice.
I suspect my motorhome is roughly typical of the usual DC wiring, though there are very many variations. From what I've made out, the house battery positive is connected to a large fuse (I'm guessing maybe 100A or so, I don't know exactly) to protect against a catastrophic short circuit somewhere.
After this large fuse, there are a few things connected by a short bus bar. There's the isolator relay that connects the house battery and the chassis battery together when the engine is running so that the alternator charges the house battery (and also when the emergency start switch is pressed). There's a self-resetting circuit breaker, protecting a wire that goes to the converter output. There's another self-resetting circuit breaker for the wire that goes to the main DC distribution panel (with a "salesman switch" or master shutoff in between). Finally, there's another self-resetting circuit breaker, I assume for circuits that are always powered, at a minimum including the control for the master shutoff switch. (There is, of course, no reason other than convenience why these various self-resetting circuit breakers couldn't be fuses or manual circuit breakers.)
From the DC distribution panel, individual fused circuits go off to all the 12V things throughout the motorhome, as expected. Mine uses the usual blade-type automotive fuses, as do most of the new ones you're likely to find. Marine, RV, or automotive fuse panels would all be more or less suitable; the RV ones mainly offer neat-looking covers and mounting and so forth, but are not unique in terms of functionality.
Having some sort of a DC distribution panel is a good idea. Certainly all the DC circuits need to be properly fused somehow or another for safety, and having inline fuses helter-skelter is hard to keep track of and untidy and generally not best practice.
I suspect my motorhome is roughly typical of the usual DC wiring, though there are very many variations. From what I've made out, the house battery positive is connected to a large fuse (I'm guessing maybe 100A or so, I don't know exactly) to protect against a catastrophic short circuit somewhere.
After this large fuse, there are a few things connected by a short bus bar. There's the isolator relay that connects the house battery and the chassis battery together when the engine is running so that the alternator charges the house battery (and also when the emergency start switch is pressed). There's a self-resetting circuit breaker, protecting a wire that goes to the converter output. There's another self-resetting circuit breaker for the wire that goes to the main DC distribution panel (with a "salesman switch" or master shutoff in between). Finally, there's another self-resetting circuit breaker, I assume for circuits that are always powered, at a minimum including the control for the master shutoff switch. (There is, of course, no reason other than convenience why these various self-resetting circuit breakers couldn't be fuses or manual circuit breakers.)
From the DC distribution panel, individual fused circuits go off to all the 12V things throughout the motorhome, as expected. Mine uses the usual blade-type automotive fuses, as do most of the new ones you're likely to find. Marine, RV, or automotive fuse panels would all be more or less suitable; the RV ones mainly offer neat-looking covers and mounting and so forth, but are not unique in terms of functionality.
