Arc fault tripping...I'm out of ideas

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crtemp

Senior Member
Location
Wa state
I have a customer that claims that his arc fault breaker trips when he is using his electric range in his kitchen. I have been to the house to troubleshoot this twice all ready. Whenever I go he cannot seem to make the arc-fault trip no matter what he does to the range. I cannot get it to trip either unless I push the test button. The first time I was there I changed out the arc-fault to a new one and it seemed to solve the problem for a month or so. He called back with the same story of the range making it trip. I went back and of course he could not get it to do it. I humored him and change out his range receptacle and made sure all connections were tight and was on my way. Three weeks later guess who's calling. What should I do at this point? Is it impossible for other circuits to effect the arc fault circuit breaker? The only thing on the arc fault breaker are some exterior lights with CFL bulbs and bedroom receptacles. Might be a bathroom exhaust fan too.
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
Is the breaker tripping from a ground fault or arc fault? Siemens, SquareD and Cutler Hammer CH breakers indicate what caused the breaker to trip. Its optional on Cutler Hammer BR's. Newer GE's don't have ground fault protection.
 

crtemp

Senior Member
Location
Wa state
Is the breaker tripping from a ground fault or arc fault? Siemens, SquareD and Cutler Hammer CH breakers indicate what caused the breaker to trip. Its optional on Cutler Hammer BR's. Newer GE's don't have ground fault protection.


I'm not sure. They always reset it before I get there.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I'm not sure. They always reset it before I get there.

Some of the indicating ones will store the cause and allow you to read it out by the proper operation sequence even after it has been initially reset. Check the breaker instructions.

A while back a situation came up in which the ground fault only occurred when somebody touched both the range metal and some other appliance metal which was grounded via an EGC simultaneously.
Does the range connection have a separate EGC and has any possible EGC to neutral jumper inside the range been removed?
You could meter the voltage or current between the range and other nearby metal surfaces to try to track this down.
 
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crtemp

Senior Member
Location
Wa state
Some of the indicating ones will store the cause and allow you to read it out by the proper operation sequence even after it has been initially reset. Check the breaker instructions.

A while back a situation came up in which the ground fault only occurred when somebody touched both the range metal and some other appliance metal which was grounded via an EGC simultaneously.
Does the range connection have a separate EGC and has any possible EGC to neutral jumper inside the range been removed?
You could meter the voltage or current between the range and other nearby metal surfaces to try to track this down.

The house is barely 2 years old. The range is 4 wire. The little jumper in the range has been removed. Can the arc fault breaker sense a ground fault like a gfci does? How could it possibly effect the arc fault load and make it trip?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
The house is barely 2 years old. The range is 4 wire. The little jumper in the range has been removed. Can the arc fault breaker sense a ground fault like a gfci does? How could it possibly effect the arc fault load and make it trip?

Almost all AFCI breakers (but not receptacles) include detection if ground faults (current imbalance) at the 30ma level. That is less sensitive than a pure Class A GFCI at 6ma.

Tapatalk!
 

crtemp

Senior Member
Location
Wa state
Is there an exhaust hood with a fan maybe fed from that bedroom circuit?

The circuit feeds stuff on the complete opposite side of the house from the kitchen. The only thing on it is exterior coach lights, a weatherproof gfi, a bedroom and a hall bathroom with a vanity light and a Panasonic exhaust fan.
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
As Gold said, the breakers have a memory so will still be able to tell you what caused them the trip. What brand and type of breaker is this?

You could try replacing the AFCI with a GFCI for testing purposes. If the homeowner calls and says the GFCI trips you need to look for a ground fault somewhere probably with a Megger. If the GFCI doesn't trip then the fun begins trying to figure out what the AFCI is seeing as a problem.
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
....You could try replacing the AFCI with a GFCI for testing purposes. If the homeowner calls and says the GFCI trips you need to look for a ground fault somewhere probably with a Megger. If the GFCI doesn't trip then the fun begins trying to figure out what the AFCI is seeing as a problem.
That is what I would do. Doing that exact kind of test on a circuit that I knew was clean is what moved me into the AFCI Hater Club.

AFCI's do trip it there is a wiring problem, but they also trip if they don't like the load they are attached to or a load they don't like on a separate circuit but the same phase.
 

LEO2854

Esteemed Member
Location
Ma
The circuit feeds stuff on the complete opposite side of the house from the kitchen. The only thing on it is exterior coach lights, a weatherproof gfi, a bedroom and a hall bathroom with a vanity light and a Panasonic exhaust fan.


The circuit that is tripping,have you checked each receptacle box for proper splices? same with the light fixtures and the fan. Somewhere you've got a neutral touching and EGC, a loose splice/connection,or the neutrals of two circuits spliced together in a switch box, also look for portable appliances such as space heaters that they could be moving around and plugging it in with the switch on.
 

jap

Senior Member
Occupation
Electrician
Last one I chased ended up being in the Vanity Light. When they chaned the bulb the screwshell twisted and hit the metal housing of the fixture creating a neutral to ground connection.
 

ELA

Senior Member
Occupation
Electrical Test Engineer
Did I miss where you said what the brand of AFCI was?
As has already been stated most include GF protection as well as Arc detection. The idea of substituting a GFCI temporarily to determine if it is the GF portion tripping is a good diagnostic tool.

From what you have described, and the range has to be on for it to occur, it sounds more like it could be noise from the range upsetting the arc detection portion.

The following is assuming you have proven it is not a GF or a valid arc fault.

When you where there testing did you have all the normal loads that are present on the AFCI circuit turned on?
It could be that it takes a certain amount of 60Hz current flowing through the breaker ( >5A ), along with noise generated by the range, in order to cause the trip to occur.

I have been observing reports of AFCI breakers nuisance trip problems for years now. I feel for all the electricians having to attempt to explain to customers why nuisance AFCI issues exist.

If it is a nuisance issue it is likely to require more elaborate test equipment than what the typical electrician has at their disposal.
Using an Oscilloscope a person could determine whether or not the range is putting out electrical noise. Or if noise is present on the AFCI circuit.

If noise was identified then you would need to determine whether the range has a defect causing the noise or if it is EMI from the range electronics that requires filtering.
 

crtemp

Senior Member
Location
Wa state
Did I miss where you said what the brand of AFCI was?
As has already been stated most include GF protection as well as Arc detection. The idea of substituting a GFCI temporarily to determine if it is the GF portion tripping is a good diagnostic tool.

From what you have described, and the range has to be on for it to occur, it sounds more like it could be noise from the range upsetting the arc detection portion.

The following is assuming you have proven it is not a GF or a valid arc fault.

When you where there testing did you have all the normal loads that are present on the AFCI circuit turned on?
It could be that it takes a certain amount of 60Hz current flowing through the breaker ( >5A ), along with noise generated by the range, in order to cause the trip to occur.

I have been observing reports of AFCI breakers nuisance trip problems for years now. I feel for all the electricians having to attempt to explain to customers why nuisance AFCI issues exist.

If it is a nuisance issue it is likely to require more elaborate test equipment than what the typical electrician has at their disposal.
Using an Oscilloscope a person could determine whether or not the range is putting out electrical noise. Or if noise is present on the AFCI circuit.

If noise was identified then you would need to determine whether the range has a defect causing the noise or if it is EMI from the range electronics that requires filtering.

The breaker is a Siemens brand. After talking with the homeowner it sounds like the range might not be causing it. He says its mostly when the hall bath exhaust fan is on while showering. He can't remember if the range has been on every time.

If it was a ground to neutral issue wouldn't it trip immediately?


Sent from my iPhone using Tapatalk
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
The breaker is a Siemens brand. After talking with the homeowner it sounds like the range might not be causing it. He says its mostly when the hall bath exhaust fan is on while showering. He can't remember if the range has been on every time.

If it was a ground to neutral issue wouldn't it trip immediately?


Sent from my iPhone using Tapatalk

Have you thought about a moisture issue in the brushes of the motor?

I noticed that in your first post, you thought there may be a bathroom fan on the AFCI that is tripping. I guess now you know.
 

ELA

Senior Member
Occupation
Electrical Test Engineer
The Siemens brand has LED indicators.
The Siemens site has a diagnostic flow chart based on what the LEDs display.

The GF portion of AFCI's are different from the newer GFCI's which have additional circuitry to specifically check for the Neutral-Ground short ( without the need for load current).

So the AFCI may not trip immediately.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
If the fan has a leakage to ground problem internally and it is on the breaker that trips, the leakage could ramp up as the fan sucks moist air.

Tapatalk!
 

crtemp

Senior Member
Location
Wa state
I'm going on Monday to look at it again. I'll try turning on the shower and fan for awhile and see if that does anything. If it trips it I'll just remove the bathroom from the circuit.
 
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