Strange fused panel behavior - seeking comments

[JeffreyG]

I'm doing a bit more work tidying up the wiring in my E-19, adding a ground bus and adding some buck regulators on sensitive electronics.


The first thing I was doing this morning was just tracing the various circuits. So I turned everything on an started pulling the 12V fuses to see what was on each circuit. So I was puzzled when pulling every fuse one by one never killed the lights or the Maxxfan.


So I finally got it. If I pull both of the top two 15A fuses, the lights and fan go off. But if one fuse is installed in either slot, they all work. That seems.....unusual to me. Can anyone comment on wiring run in such a fashion?


I guess I'm not understanding the wiring and also a bit worried that the circuit would have to pull 30A to melt both breakers.

[MVA]

Jeffery,

As you probably already unfortunately figured out, it appears that there is some type of wiring short between the two different circuits. It may not help, but I did the same exercise as you started. The attached chart is our 12 VDC circuits. I added fuses to positions 5 & 6 for additional equipment post-delivery on our E19.

--Steve

[wackyburggeezer]

It sounds like both load sides of the two fuses are connected somewhere in the trailer. If you were to have a fault that exceeded 15 amps, first one would blow, and then the other. Have fun troubleshooting this one!

[Brian B-P]

Originally Posted by MVA

As you probably already unfortunately figured out, it appears that there is some type of wiring short between the two different circuits.

That would be it. Some idiot presumably made a chain of devices which goes in a complete loop from one fuse panel position to the other.

I worked with someone who was a qualified electrician, and he described a similar situation with 120 V AC circuits in a house where he had been talked into helping the homeowner (his neighbor) add a light fixture. Of course then he had to put hours more effort into tracing out the circuits and correcting them, since he couldn't leave it in good conscience, even though he didn't create the problem wasn't even being paid for his work. He used the experience as an example of why he avoids getting anywhere near the garbage that passes for wiring in other people's houses... especially those that amateurs have modified. I would approach any RV as possibly being like an amateur basement renovation.

[Rossue]

Oddly, am having a similar situation at home now. Did a kitchen remodel ten years ago and had some circuits moved inside to a sub panel to power a 50 amp & 30 amp breaker for an induction cooktop and electric wall oven. Another 30 amp plus four 20 amp breakers were also put into the sub panel.

This is all in a small laundry room. While we were away( stuff always seems to happen then- am I right?) a small hand blender was plugged into a power strip that had both washer/dryer plugged in. At startup of the little hand held mixer ther was an arc and all power(ceiling light plus two pair of 120v plugs were dead.

Two 15 amp breakers tripped. If one is thrown back open it stays, however when throwing the other one the first one trips & vice-versa.