Short on Neutral Bus?

[john1450]

I am in the process of a kitchen remodel. Kitchen appliances and other rooms were on the same circuits, so I’ve split these up and reworked the electrical to put proper appliances on their own circuits. I’m also replacing old Challenger breakers with AFCI/GFCI Eaton breakers.

As I was turning one of the circuits back on, I got a decent pop/spark that appeared to occur at the neutral bus. No evidence of the spark anywhere I can find though. And even more concerning, the breaker (an AFCI breaker) did not trip.

I’ve checked all the circuits for shorts before powering them on and didn’t get any continuity. Any ideas on exactly what would cause this and not cause the breaker to trip? Could a defective breaker cause something like this?

 

[kwired]

Loose connection, either a conductor or a link to other bus sections? If it were a short circuit or ground fault the breaker would likely tripped, if it were just normal load it is similar arc as would occur in a switch carrying same load when you operate said switch.

 

[letgomywago]

Depending on the type of breaker too it may not have GFPE in the arc fault anymore and so it wouldn't trip the arc fault if it's a dirty nuetral and is a return for some odd light fixture or whatever.

 

[john1450]

I checked the connections. Everything is tight. Breaker did not have GFCI. I’m thinking maybe a short in the breaker between the hot and neutral? I didn’t have a spare at the time but I’ll try replacing it and see what happens…

 

[rambojoe]

A spark or flash can appear to be anywhere..
Find the black- then you have your answer...

 

[john1450]

A spark or flash can appear to be anywhere..
Find the black- then you have your answer...

Yeah. I think that’s what I’ve got to do unfortunately, but if the hot and neutral were shorted somewhere, it should have tripped the breaker. That’s the part that really confuses me and makes me question the breaker.

 

[letgomywago]

Was it the breaker pigtail to the bus. If the breaker is in the on position even without having a circuit attached the load of the electronics can get you.