I was putting a battery disconnect on my trailer this afternoon and noticed this:Click For Full-Size ImageI'm not sure what the point of having two circuit breakers in series like this is, especially since the first one connected to the battery (the one at the bottom of the photo) appears to be shorted out. They appear to be the same size breakers. :hThis came from the factory like this unless the dealer did something before delivery. I'm the original owner and it hasn't been in the shop for any type of electrical work since I've owned it. Am I missing something?

Are you certain it is not the larger red wire (on the post with the red jumper and smaller white wire) that goes to the battery?Those breakers should not be in series. Battery should go to both and then each one feed it’s own circuits.Curious why you think the one is “shorted out”. If the breakers are good you will have +12 vdc on both posts at all times except when they trip.

I'd guess they are not the same current rating. The first one is the main one, and there are two higher current circuits connected to its output (via the lower lug of the upper breaker). The second one presumably has a lower rating and is for some other stuff.It may not be the cleanest way of doing things, but it's not entirely senseless in my estimation.

Not in series. Looks ok except the mystery white wire in with the reds at the lower terminal of the upper CB. White is usually neg.

BB_TX wrote:Are you certain it is not the larger red wire (on the post with the red jumper and smaller white wire) that goes to the battery?Those breakers should not be in series. Battery should go to both and then each one feed it’s own circuits.I will double check, but I'm fairly sure the battery the large red wire on the bottom post in the picture. I'm almost certain the large red wire on bottom post of the upper breaker is the main load center inside the trailer.BB_TX wrote:Curious why you think the one is “shorted out”. If the breakers are good you will have +12 vdc on both posts at all times except when they trip.If you look at the full size picture, it's clearer. The ring terminal on the upper post of the bottom breaker is touching the bottom post.

BFL13 wrote:Not in series. Looks ok except the mystery white wire in with the reds at the lower terminal of the upper CB. White is usually neg.As far as I can tell, there is no concept of color code in the RV industry. At least they used red and black for the main battery cables. Every interior wire I've seen has been white, occasionally with a stripe.

12V circuit breakers in series? | Good Sam Community

wa8yxm
Explorer III
Sep 08, 2019
The breaker with just 2 wires is a "MAIN" same as the MAIN on your 120 volt panel. the breaker with several wires hooked to each lug is a "Branch" there are other branch breakers hooked to one of the lugs.
cavie
Explorer
Sep 08, 2019
Not is series. Red wire is hot to battery. I don't think the white wire belongs there.
BB_TX
Nomad
Sep 08, 2019
happy2rv wrote:
...
BB_TX wrote:
Curious why you think the one is “shorted out”. If the breakers are good you will have +12 vdc on both posts at all times except when they trip.

If you look at the full size picture, it's clearer. The ring terminal on the upper post of the bottom breaker is touching the bottom post.

Ahh. I missed that. That bypasses that breaker. If it came new like that then it would not surprise me if they were also wired wrong.
happy2rv
Explorer
Sep 08, 2019
BFL13 wrote:
Not in series. Looks ok except the mystery white wire in with the reds at the lower terminal of the upper CB. White is usually neg.

As far as I can tell, there is no concept of color code in the RV industry. At least they used red and black for the main battery cables. Every interior wire I've seen has been white, occasionally with a stripe.
happy2rv
Explorer
Sep 08, 2019
BB_TX wrote:
Are you certain it is not the larger red wire (on the post with the red jumper and smaller white wire) that goes to the battery?
Those breakers should not be in series. Battery should go to both and then each one feed it’s own circuits.

I will double check, but I'm fairly sure the battery the large red wire on the bottom post in the picture. I'm almost certain the large red wire on bottom post of the upper breaker is the main load center inside the trailer.

BB_TX wrote:
Curious why you think the one is “shorted out”. If the breakers are good you will have +12 vdc on both posts at all times except when they trip.

If you look at the full size picture, it's clearer. The ring terminal on the upper post of the bottom breaker is touching the bottom post.
BFL13
Explorer II
Sep 08, 2019
Not in series. Looks ok except the mystery white wire in with the reds at the lower terminal of the upper CB. White is usually neg.
DrewE
Explorer II
Sep 08, 2019
I'd guess they are not the same current rating. The first one is the main one, and there are two higher current circuits connected to its output (via the lower lug of the upper breaker). The second one presumably has a lower rating and is for some other stuff.

It may not be the cleanest way of doing things, but it's not entirely senseless in my estimation.
BB_TX
Nomad
Sep 08, 2019
Are you certain it is not the larger red wire (on the post with the red jumper and smaller white wire) that goes to the battery?
Those breakers should not be in series. Battery should go to both and then each one feed it’s own circuits.
Curious why you think the one is “shorted out”. If the breakers are good you will have +12 vdc on both posts at all times except when they trip.

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