gfi tripping with no load?

Status
Not open for further replies.
J

journeyman0217

Senior Member
Location
philadelphia,pa
Buddy called me up and said he had a gfi receptacle that was tripping. Said the frig was on the load side of the gfi. He pulled the outlet out and took the load side conductors out and installed them on the line side. He said it worked fine for a day then he came home one day and noticed that the gfi was tripped again. He asked me what the problem could be? I'm not sure what to think because he said he had nothing plugged into the receptacle and everything is hooked to line side. Any ideas? He did say that he replaced the receptacle. I was thinking if there was a problem in the wiring before the gfi could it still trip the gfi even though it is on the line side?
 
G

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Some GFCIs will also trip if they detect a low impedance connection between neutral and EGC on the load side, even if there is no leakage from the ungrounded conductor.
If that part of the circuit is intermittently failing, then you could get a trip from that even with no wires connected to the load side.
Did you disconnect both the hot and the neutral on the load side?
 
J

journeyman0217

Senior Member
Location
philadelphia,pa
This happened to a friend and he called to ask what it would be, I assume he left no wires on the load side. When you say "low impedance between neutral and ground on load side", it will detect even if the "load" is actually tied into the line side?
 
G

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
journeyman0217 said:
This happened to a friend and he called to ask what it would be, I assume he left no wires on the load side. When you say "low impedance between neutral and ground on load side", it will detect even if the "load" is actually tied into the line side?
Click to expand...

AFAIK the extra ground to neutral bond must actually occur between something on the load side neutral terminal and the EGC.
 
J

JFletcher

Senior Member
Location
Williamsburg, VA
If the frig still trips a properly wired new GFCI, I'd say the frig is faulty. Nuisance tripping of older GFCI is uncommon in my experience, most seem to fail to reset. Either way, it's a lot cheaper and easier to replace and older GFCI first before eyeballing a new thousand dollar icebox or tearing into appliance wiring. He may want to check the cord for pinches or mice chew marks which are exposing bare wiring.
 
Little Bill

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
journeyman0217 said:
Buddy called me up and said he had a gfi receptacle that was tripping. Said the frig was on the load side of the gfi. He pulled the outlet out and took the load side conductors out and installed them on the line side. He said it worked fine for a day then he came home one day and noticed that the gfi was tripped again. He asked me what the problem could be? I'm not sure what to think because he said he had nothing plugged into the receptacle and everything is hooked to line side. Any ideas? He did say that he replaced the receptacle. I was thinking if there was a problem in the wiring before the gfi could it still trip the gfi even though it is on the line side?
Click to expand...

Wait....... Are you saying the GFCI has a load side connection and it was changed to the line side and then the fridge is still plugged into the GFCI receptacle?

Or are you saying the fridge was on a receptacle Protected by the GFCI, then was changed to line side?

If the former, then there might be a problem with the fridge.
If the latter, then most likely a bad GFCI.
 
ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
Little Bill said:
Wait....... Are you saying the GFCI has a load side connection and it was changed to the line side and then the fridge is still plugged into the GFCI receptacle?

Or are you saying the fridge was on a receptacle Protected by the GFCI, then was changed to line side?

If the former, then there might be a problem with the fridge.
If the latter, then most likely a bad GFCI.
Click to expand...

My eyes crossed on that description as well.
 
J

journeyman0217

Senior Member
Location
philadelphia,pa
Little Bill said:
Wait....... Are you saying the GFCI has a load side connection and it was changed to the line side and then the fridge is still plugged into the GFCI receptacle?

Or are you saying the fridge was on a receptacle Protected by the GFCI, then was changed to line side?

If the former, then there might be a problem with the fridge.
If the latter, then most likely a bad GFCI.
Click to expand...

Sorry for the confusion, the frig was plugged into a receptacle that was gfi protected, not the actual gfi. And yes when he explained the situation my first response was it was a bad gfi. Then he said he replaced it and it still does it. 2 bad gfi's in a row? I guess it is possible....
 
Electric-Light

Electric-Light

Senior Member
journeyman0217 said:
Buddy called me up and said he had a gfi receptacle that was tripping. Said the frig was on the load side of the gfi. He pulled the outlet out and took the load side conductors out and installed them on the line side. He said it worked fine for a day then he came home one day and noticed that the gfi was tripped again. He asked me what the problem could be? I'm not sure what to think because he said he had nothing plugged into the receptacle and everything is hooked to line side. Any ideas? He did say that he replaced the receptacle. I was thinking if there was a problem in the wiring before the gfi could it still trip the gfi even though it is on the line side?
Click to expand...

how long has it ran trouble free for?
 
Electric-Light

Electric-Light

Senior Member
GoldDigger said:
AFAIK the extra ground to neutral bond must actually occur between something on the load side neutral terminal and the EGC.
Click to expand...

It doesn't have to be ground. It could be to neutral upstream of outlet as well. GFI is a high sensitivity clamp meter around a lamp zip cord. The current loop causes induced current in the clamp meter, but the current in return path is the same as well, but it's in the opposite direction so it cancels out perfectly. The current reading is any current flowing through the conductors that do not cancel out perfectly. A ground to neutral short forms a parallel conductor that is not inside the clamp, so it prevents a perfect cancellation.
 
J

journeyman0217

Senior Member
Location
philadelphia,pa
Electric-Light said:
No, I was asking how long he's had this fridge at this particular place before he started having problems. If it ran fine for months/years and it just started happening, it's likely a legit problem.
Click to expand...

oh, yeah he moved in a year ago and the problem just started to occur. that's why I posted the question on the forum because I think it is something legit and not just a bad gfi...
 
MNSparky

MNSparky

Senior Member
Location
Minneapolis, MN
Occupation
Electrical Contractor - 2023 NEC
ptonsparky said:
Now that he as replaced the GFCI, I'm inclined to think agree with you, unless he goofed up with the replacement.
Click to expand...

Did he put it back together with the line and the load connected or is everything still on the line side? Can you verify its wired correctly?
 
Electric-Light

Electric-Light

Senior Member
Sometimes GFIs trip from old electronic ballasts on line side. They used a hefty choke reactor for power factor correction and kicked back a very brief but high voltage spike. Trip due to inductive surge always happen when the switch is opened. Motors, magnetic ballasts, transformers can cause it. It doesn't happen every time, but when it does, it is always on break and if you can not duplicate this, I would suspect something else.

Any new plug-in load or stuff he installed into the house right before this?
 
Status
Not open for further replies.
Top