Confused
Don,
I am not clear on what you are trying to do or maybe we are talking about different things.
Hot Battery Bus.
The ONLY thing on the HOT Battery Bus (on the airliners I flew) was the FIRE BOTTLES, because you never want to switch them off or have them inoperative because they were down stream of a failed switch or solenoid.
Everything else should be the other side of the MASTER SWITCH SOLENOID.
As we don?t normally have Fire Bottles on Rvs, the only thing that will always be live is the cable between the Battery and the MASTER SWITCH SOLENOID. (I suppose you could call that cable, the Hot Battery Bus, but there should be nothing on it, except the Master Switch Solenoid.)
That cable should be short for that reason, as stated by others.
In the event of a fire, selecting the Master Switch OFF, turns off EVERTHING in the aircraft, EXCEPT the cable between the Battery and the Master Switch Solenoid.
So on an RV I don't see why you would have a HOT Battery Bus.
(The above is an Airline Pilots perspective, not and electrical engineers.)
I can't give you an engineer?s perspective as I did not wire my RV, but paid a Pro. to do it. But I can tell you what he did; and he is a disciple of Nuckholls.
It is wired such that with the Master switch OFF, no live wires pass through the Firewall. The wire to the Master Switch is the Solenoid Earth; not the positive.
This is not my forte, so I stand ready to be shot down.
Pete.
PS. Don, ironic surname. Oop! Sorry.