Battery cut off switch question

Lynnmor wrote:

Bobbo wrote:

Lynnmor wrote:

beemerphile1 wrote:
On a trailer it must be on the positive and the breakaway switch should be wired prior to the disconnect for safety. Sooner or later the trailer will be towed with the disconnect open but the breakaway will still function.

Breakaway switches can malfunction, brake wires can become shorted, keys can be accidentally pulled and there is no fuse, so do you keep a wire cutter right there to quickly disconnect before there is a fire?

Now, you are being silly. Beemerphile1 is spot on. A disconnect switch, which is the subject of this thread, does not protect from any of the things that you mention.

You did not understand, if there is a fault the disconnect switch can be used to quickly remove power. I might be silly but I do have a clue about circuits with no fuses. Wire it any way you like, I don't care.

Actually, I understand fully. If there is a fault, it is unlikely to be while you are standing there to hit the switch. There is a reason why NO manufacturer wires a breakaway switch through a disconnect switch.

Bobbo wrote:

Lynnmor wrote:

beemerphile1 wrote:
On a trailer it must be on the positive and the breakaway switch should be wired prior to the disconnect for safety. Sooner or later the trailer will be towed with the disconnect open but the breakaway will still function.

Breakaway switches can malfunction, brake wires can become shorted, keys can be accidentally pulled and there is no fuse, so do you keep a wire cutter right there to quickly disconnect before there is a fire?

Now, you are being silly. Beemerphile1 is spot on. A disconnect switch, which is the subject of this thread, does not protect from any of the things that you mention.

You did not understand, if there is a fault the disconnect switch can be used to quickly remove power. I might be silly but I do have a clue about circuits with no fuses. Wire it any way you like, I don't care.

Lynnmor wrote:

beemerphile1 wrote:
On a trailer it must be on the positive and the breakaway switch should be wired prior to the disconnect for safety. Sooner or later the trailer will be towed with the disconnect open but the breakaway will still function.

Breakaway switches can malfunction, brake wires can become shorted, keys can be accidentally pulled and there is no fuse, so do you keep a wire cutter right there to quickly disconnect before there is a fire?

Now, you are being silly. Beemerphile1 is spot on. A disconnect switch, which is the subject of this thread, does not protect from any of the things that you mention.

beemerphile1 wrote:
On a trailer it must be on the positive and the breakaway switch should be wired prior to the disconnect for safety. Sooner or later the trailer will be towed with the disconnect open but the breakaway will still function.

Breakaway switches can malfunction, brake wires can become shorted, keys can be accidentally pulled and there is no fuse, so do you keep a wire cutter right there to quickly disconnect before there is a fire?

On a trailer it must be on the positive and the breakaway switch should be wired prior to the disconnect for safety. Sooner or later the trailer will be towed with the disconnect open but the breakaway will still function.

On a MH it is normally in the positive but doesn't really matter.

No ZAP :S

Had my head where the sun doesn't shine .....brain fart!

Car audio shop guy told me the 18 inch rule for the battery fuse on the positive cable (to the amplifier) was in case of a car crash. Don't want a fire. RVs can get in crashes too.

Not having a battery cut off, or fuse, or CB in any main battery cable mite be better, then you don't have to figure it out. Many RVs do not have any protection in any main battery cables, and for good reason,.....being if it is all installed correctly, only a major crash would ever sever a battery cable.
And it doesn't make any sense to have a battery cutoff, and then start bypassing it, for any reason. How many have come back to dead batteries because the battery cutoff was bypassed ? But whatever work for you.

As others have said, close to the battery is only necessary if it is a fuse or breaker also. As long as it is JUST a disconnect switch, anywhere is fine.

Positive or negative wire, either one, is fine with a single exception. Your TT probably has a breakaway brake switch. That should NEVER be disconnected from the battery. Ever. If you disconnect that switch and tow, the emergency brakes for the trailer are non-functional. Since the breakaway brakes usually use the frame ground, disconnecting the negative wire disconnects the breakaway brakes. The usual way around this is to disconnect the positive wire, but wire the breakaway brakes BEFORE the disconnect switch.

Blazing Zippers wrote:
All along, I've been under the impression that a cut off switch should be placed close to the battery and on the positive side of the system. Is this right?

Well.. it should be the first or 2n device "post battery" that is the cable from teh battery should run to either teh Switch or a fuse or breaker first. then the other of those two items.

Positive is traditional. but not necessary.