ECN Forum
Posted By: HotLine1 AFCI/GFCI question - 10/29/10 11:55 PM
On a recent final, using a bug-eye tester, the kitchen counter receptacles (GFI devices) tripped the AFCI in 1 SA circuit that also fed the DR.

I am not aware that a bug-eye could trip an AFCI CB.

I had a few jobs that HOs installed AFCI CBs on above ground pools, and testing the pool recept with the bug-eye did not trip the AFCI in those cases.

Could it be the electronics within the GFI device?

Any input gentlemen?
Posted By: KJay Re: AFCI/GFCI question - 10/30/10 01:12 AM
It sounds like the EC wired the kitchen counter outlets from the dining room SABC, which is probably why it is on the AFCI cb.
The thing is, even though IMO, having it wired that way is not good wiring practice because it may likely result in a lot of false trips for the occupants, I can’t think of any code article that would actually forbid it.
Posted By: HotLine1 Re: AFCI/GFCI question - 10/30/10 03:41 AM
Kjay:

Yes, the DR and 1 SABC is one and the same on AFCI CB. I'm interested in if anyone has a clue about tripping the AFCI CB thru a GFI device on that circuit, causing the trip with a 'bug-eye'/'cube' tester.
Posted By: gfretwell Re: AFCI/GFCI question - 10/30/10 06:12 AM
If this tester normally does not trip (5ma) GFCIs and it trips this (30ma) AFCI, I suspect you have 26-28ma of fault current ... or maybe just a shorting fault in that box that any plug might trigger.
Posted By: KJay Re: AFCI/GFCI question - 11/01/10 03:57 PM
Oops. I totally missed on that one.
I found these related FAQ’s on Siemens website. They don’t really offer any definitive answers though.
I’ve had that happen occasionally, but very infrequently, and I’m wondering if it might possibly have something to do with the length of the circuit, among other things.


Should an AFCI breaker trip when using a hand-held tester?
To clarify, these devices are only indicators and not "testers." Please see the attached letter from UL that addresses this issue. Click Here
The hand-held indicators currently on the market, do not generate a genuine arc and, therefore, the only true way to verify the operation of any AFCI (Branch Feeder and Combination Type), regardless of brand, is to use the Push-to-Test button.


Can you use a hand-held GFCI tester to test an AFCI circuit breaker?
No. While some GFCI testers may cause an AFCI to trip, these devices are not testing the arc detection capability of the breaker. AFCIs utilize a differential sensor to detect leakage of current in a circuit. When the GFCI tester creates a leakage of current greater than the threshold level of the AFCI's differential sensor, the device will open. However, this fault detection is not intended to provide personnel protection, as the AFCI trip thresholds for differential current vary by manufacturer but are typically 30mA to 60mA – far above the 5mA level required for personnel protection. In addition, AFCIs do not specifically include grounded neutral protection.


Will an AFCI trip when testing a GFCI receptacle installed on the same circuit?
If a GFCI receptacle is installed on the load side of an AFCI it is possible for both the AFCI and the GFCI to trip on a ground fault if the leakage current exceeds the threshold for both devices. It is also possible for the AFCI to trip and the GFCI to not trip since the two devices could race each other. The functionality of each device should be verified by operation of the Push-to-Test button.
Posted By: HotLine1 Re: AFCI/GFCI question - 11/02/10 02:00 AM
Greg:
The tester is a Ideal cube (bug-eye) with GFCI test button. It does trip 5ma GFCI devices and CBs. I am wondering why it tripped an AFCI. 20 amp circuit thru DR & on to countertop. GFI devices on counter top, duplex TR receptacles in DR. Put tester in GFI device, push button, AFCI trips! Think it's the electronics in the GFI device?

This has not happened in the past; just on this one SFD final.
Posted By: HotLine1 Re: AFCI/GFCI question - 11/02/10 02:02 AM
KJay:
Thanks for the info. I just want Gregs opinion in addition.

Posted By: gfretwell Re: AFCI/GFCI question - 11/02/10 02:24 AM
Is it a Cutler Hammer AFCI? They do make one that trips at 5ma.
© ECN Electrical Forums