# Arc fault tripping



## stile (May 22, 2008)

I'm working on a multifamily unit. I'm having a problem with one of the arc faults that go to the heaters. Everytime we turn on a 15 amp breaker on either phase, the arc fault trips. if no other 15 amp breaker is on it works fine. we have changed the arc fault twice and have also changed phases in the panel. I'm pretty much dumbfounded on the problem


----------



## Roger123 (Sep 23, 2007)

Stile,

Need more info., but the actions you are describing are upstream/ahead of the arc fault breaker and should not affect the said arc fault breaker's electronic at all. So, I'm thinking maybe when another breaker in this panel is closed/turn on, it is causing a back feed to the said arc fault breaker thought the neutral connection on the breaker causing an inbalance of current and tripping the ground fault protection electronics of the affected breaker.


----------



## electricalperson (Jan 11, 2008)

Roger123 said:


> Stile,
> 
> Need more info., but the actions you are describing are upstream/ahead of the arc fault breaker and should affect the said arc fault breaker's electronic at all. So, I'm thinking maybe when another breaker in this panel is closed/turn on, it is causing a back feed to the said arc fault breaker thought the neutral connection on the breaker causing an inbalance of current and tripping the ground fault protection electronics of the affected breaker.


i would think thats whats happening also. open up boxes and check for other circuits neutrals tied together with the arc fault neutral. 

ideals suretest circuit analyzer checks for this problem. 

also when all the other circuits are open go to the load side of each breaker when that arc fault is on to see if you are backfeeding it somehow.


----------



## stile (May 22, 2008)

thanks for the input. i won't be back to this job for a couple days, so i won't have any feed back til then, got sent back to rough-ins for about a week


----------

