Two fuses required to de-energize a lighting circuit

[jeff48356]

I was just on a service call the other day to replace a couple of bad receptacles, and discovered that I needed to remove TWO fuses to de-energize the circuit. Yes, fuses, not breakers; the house was built in 1963. And I did recommend a service upgrade and gave them a quote for it. But I was wondering if any of y'all have ever run into this situation before. I have a few times. What steps would you typically take to resolve this issue? I realize if I do a service change and I happen to land those circuits on breakers on opposite legs, they will trip.

 

[Dennis Alwon]

I would just disconnect one fuse and cap off the wire. It appears they just wired a loop circuit

 

[augie47]

I've seen it a few times especially on older installations. Unless the homeowner wants you to troubleshoot the problem and remove the "link", I would do as Dennis suggests.

 

[ptonsparky]

Yes, seen it before. Either cap it or trace it out, but that can of worms may not be one you want to open.

 

[Little Bill]

Possibly one of the circuits is backfed/crossed from another circuit. This happens most times in a light switch box.

 

[readydave8]

Yes usually at light switch, have diagnosed over phone more than once

 

[augie47]

Realize, of course, that once you remove the dual feed they may start blowing the single fuse and it will "be all your fault"..

 

[jeff48356]

This could also be something as simple as the kitchen sink light and garbage disposal being operated off a stack switch, where it had been previously replaced and the homeowner failed to remove the tab between the top and bottom to separate the circuits. That would be the first place I will look if I get the job to do the service upgrade.

 

[junkhound]

Add a yellow dual feed safety placard...

 

[Little Bill]

This could also be something as simple as the kitchen sink light and garbage disposal being operated off a stack switch, where it had been previously replaced and the homeowner failed to remove the tab between the top and bottom to separate the circuits. That would be the first place I will look if I get the job to do the service upgrade.

The two circuits would have to be from the same leg in the panel, otherwise, it would create a dead short.

 

[jeff48356]

The two circuits would have to be from the same leg in the panel, otherwise, it would create a dead short.

Yes, that's what is probably going on; they happen to be on the same leg. I've seen this other times where they were on opposite legs and one of the breakers would keep tripping, and that's what the problem was. All I had to do was break off the tab.