One more AFCI question

[RichB]

Hi all and TIA --

I have searched and can't seem to find an answer so here goes--

I was asked to look at a problem in a friends new house(he's building it). He had Journeyman friend of his wire it-- and they don't have an answer either---
Ok problem:

Two bedrooms with the same problem-- Each bedroom on a single circuit--recepts and lighting--1 room has 3 Commercial IEC rated cans and the other has 2--Close the AFCI breaker and all is fine--turn on a light or plug something into the recept and the AFCI trips--does not matter what the load is--anytime it comes under load it trips.

We have hand over handed the runs from panel to the end--nothing is stapled too tight and all connections are good, even megged it out--500Mohms plus(L-N,L-G,N-G, all ends floated and not touching anything). He was using CFLs at first-then went to incandescent--no change

It is a Square D Homeline panel-15A breakers-

Short of buying new breakers-- is there anything I missed?? Got me stumped-

Sorry if this is a bit disjointed but it's 0400 and I have just pulled a double and a half so I am a weee bit tired

As always--Thanks all!!

Rich

 

[augie47]

Silly question, but have you checked to see if the correct branch circuit neutral is connected to the correct AFCI breaker or could they possibly have been switched. On occasion, I have found panels where the electrician (usually homeowner) failed to route the branch circuit neutral through the breaker and the result is the same: breakers trips at application of any load.

 

[Dennis Alwon]

If the circuit trips when a load is connected then there is a neutral and ground switched, or neutrals connected to the wrong place as gus stated. I had this one time and my high school summer helper connected the neutral to the green and the white to the egc on the recep. Circuit was fine until something was connected. You are missing something somewhere.

 

[CONDUIT]

Most likely equipment ground is touching the neutral conductor perhaps in one of the receptacle boxes. It is easy for that to happen when the equipment grounding conductors are bare.

 

[SparkBox]

AFCI Problems

AFCI Problems

Yes Yes Yes to Conduit's reply.
Having more than 400 new homes wired under my belt,
I have found that the bare ground touching the neutrals screws(due to not pushing the ground back far enough) has been the problem 100% of the time.
So there. love ya. mean it.

 

[templdl]

Silly question, but have you checked to see if the correct branch circuit neutral is connected to the correct AFCI breaker or could they possibly have been switched. On occasion, I have found panels where the electrician (usually homeowner) failed to route the branch circuit neutral through the breaker and the result is the same: breakers trips at application of any load.

Are you sure you don't have the 2 ckts wired as a "home run" sharing a neutral? I would also zero in on a neutral problem as augie47 has suggested.

Just for grins disconnect all of the loads and remove light bulbs etc. turn off the breakers for both circuits, remove the neutrals from the AFCI breakers and check the resistance between the neutrals to assure that they are insulated and isolated from one another. Then check check to see if each is insulated and isolated from the neutral/bround bar.
You may have an issue where the neutral may have cone into contact with a EGC which is not very likely given the description you gave of your problem.
If there is no continuity at least you can rull out the posibility of neutral currents straying back to the panel via a different path other than the AFCI resulting in the AFCI tripping on GF.