Jul-09-2021 07:47 PM
Jul-10-2021 04:32 PM
BB_TX wrote:DrewE wrote:ktmrfs wrote:
2) A neutral/ground fault. If a GFCI detects ground and neutral legs are connected they trip. Code says ground and neutral can only be bonded at the panel. So for about the last 10 years or more GFCI will trip on this fault.
I believe that's been a part of the code (more specifically, the UL requirements for GFCIs) for something closer to 30 years. I've had a tough time sussing out exactly when the actual requirements came into effect, but it has been decades.
A neutral/ground fault causes a a current imbalance at the outlet due to some of the current that should go thru the neutral pin now goes thru the ground pin leading to that 5 ma or greater hot/neutral difference that causes a trip. That’s where the name ground fault circuit interrupter, GFCI, comes from.
Jul-10-2021 01:42 PM
Jul-10-2021 01:24 PM
Jul-10-2021 01:12 PM
Bud
USAF Retired
Pace Arrow
Jul-10-2021 12:12 PM
wnjj wrote:BB_TX wrote:DrewE wrote:ktmrfs wrote:
2) A neutral/ground fault. If a GFCI detects ground and neutral legs are connected they trip. Code says ground and neutral can only be bonded at the panel. So for about the last 10 years or more GFCI will trip on this fault.
I believe that's been a part of the code (more specifically, the UL requirements for GFCIs) for something closer to 30 years. I've had a tough time sussing out exactly when the actual requirements came into effect, but it has been decades.
A neutral/ground fault causes a a current imbalance at the outlet due to some of the current that should go thru the neutral pin now goes thru the ground pin leading to that 5 ma or greater hot/neutral difference that causes a trip.
They will trip even with nothing plugged into the receptacle. The GFCI device itself attempts to inject current into the neutral wire and if it flows around the neutral/ground loop it trips the hot/neutral mismatch detector you are referring to. So it really is a separate feature.
Jul-10-2021 10:11 AM
BB_TX wrote:DrewE wrote:ktmrfs wrote:
2) A neutral/ground fault. If a GFCI detects ground and neutral legs are connected they trip. Code says ground and neutral can only be bonded at the panel. So for about the last 10 years or more GFCI will trip on this fault.
I believe that's been a part of the code (more specifically, the UL requirements for GFCIs) for something closer to 30 years. I've had a tough time sussing out exactly when the actual requirements came into effect, but it has been decades.
A neutral/ground fault causes a a current imbalance at the outlet due to some of the current that should go thru the neutral pin now goes thru the ground pin leading to that 5 ma or greater hot/neutral difference that causes a trip.
Jul-10-2021 10:09 AM
DrewE wrote:ktmrfs wrote:
2) A neutral/ground fault. If a GFCI detects ground and neutral legs are connected they trip. Code says ground and neutral can only be bonded at the panel. So for about the last 10 years or more GFCI will trip on this fault.
I believe that's been a part of the code (more specifically, the UL requirements for GFCIs) for something closer to 30 years. I've had a tough time sussing out exactly when the actual requirements came into effect, but it has been decades.
Jul-10-2021 10:07 AM
Jul-10-2021 08:15 AM
Bud
USAF Retired
Pace Arrow
Jul-10-2021 08:06 AM
ktmrfs wrote:
2) A neutral/ground fault. If a GFCI detects ground and neutral legs are connected they trip. Code says ground and neutral can only be bonded at the panel. So for about the last 10 years or more GFCI will trip on this fault.
Jul-10-2021 07:48 AM
BB_TX wrote:
I think you mean GFCI outlets. I haven't heard of any TTs having GFCI breakers installed.
GFCI outlets trip on a very small imbalance (as little as 5 ma) in current between the hot pin and the neutral pin. They don't trip on overcurrent or voltage surge.
Jul-10-2021 07:44 AM
Jul-10-2021 07:05 AM
Jul-10-2021 05:38 AM
Bud
USAF Retired
Pace Arrow