Wiring Puzzle

[Jim Katen]

OK. I'm stumped. 

A cable enters this panel from the lower left side and exits the panel at the upper left side. 

This cable's black wire runs through the panel uninterrupted. 

This cable's lower white wire lands on a 20-amp breaker. 

This cable's upper white wire lands on the neutral terminal bar. 

Of course, nothing is labeled.

What do you suppose someone was trying to achieve here? 

What do you suppose he did achieve here? 

 

[John Ghent]

Is the red wire lower left fried? And the one above marked Kitchen?

[Marc]

Was there a wall switch nearby?

[Chad Fabry]

I suppose the energized white wire is feeding the bottom cable black wire. The upper white wire is the neutral for the black wire.  I wonder if the ground wire was acting as a neutral for the bottom black load.

The single breaker could control two  loads anywhere in the house from the one location. I can't think of any compelling reason to wire it that way. 

[Jim Katen]

15 hours ago, John Ghent said:

Is the red wire lower left fried? And the one above marked Kitchen?

Yes. In fact it was fizzing the whole time I was trying to figure out everything else. I eventually pulled that breaker, tightened it up, and put it back just because the fizzing noise was bothersome. 

[Jim Katen]

15 hours ago, Marc said:

Was there a wall switch nearby?

It's in a garage with several nearby switches, but nothing out of the ordinary. All of the switches seemed to work fine. 

[Jim Katen]

11 hours ago, Chad Fabry said:

I suppose the energized white wire is feeding the bottom cable black wire. The upper white wire is the neutral for the black wire.  I wonder if the ground wire was acting as a neutral for the bottom black load.

The single breaker could control two  loads anywhere in the house from the one location. I can't think of any compelling reason to wire it that way. 

Possibly. This one just makes my brain hurt. 

[Marc]

7 hours ago, Jim Katen said:

It's in a garage with several nearby switches, but nothing out of the ordinary. All of the switches seemed to work fine. 

It would work fine if the black wire was the return for a switched circuit.  The lower white would be the supply and the upper white delivered a neutral connection to whatever was being switched.

[Chad Fabry]

8 hours ago, Marc said:

It would work fine if the black wire was the return for a switched circuit.  The lower white would be the supply and the upper white delivered a neutral connection to whatever was being switched.

It would. No matter what, it's not the simplest way to accomplish whatever they did.

[Jim Katen]

14 hours ago, Marc said:

It would work fine if the black wire was the return for a switched circuit.  The lower white would be the supply and the upper white delivered a neutral connection to whatever was being switched.

I see how that could work. But if that's what's going on, whoever did it must be cognitively impaired. 

It would also violate 404.2(C) (neutrals have to run to switches)  

[Marc]

49 minutes ago, Jim Katen said:

I see how that could work. But if that's what's going on, whoever did it must be cognitively impaired. 

It would also violate 404.2(C) (neutrals have to run to switches)  

404.2(C) is a new one, right?  Which cycle?

[Jim Katen]

2011. 

As I recall, it was added because of all these "smart" gizmos that might need a neutral at the switch location.