New golf carts service repair shop. The outlets circuits are all fed by GFCI breakers. there are 3 lighting circuits separate from the outlets and in separate conduit. Outlets mainly serve EZGO high frequency battery chargers. Before construction was totally complete the owner brought in some carts to charge. Came in the next morning turned on the lights and every GFCI breaker that had a charger plugged in tripped. Reset breakers and all worked fine. The breakers will trip only after the charger has been plugged in for a few minutes. If you turn on lights then plug in chargers they will not trip. We have been through all termination to clear up crossed neutrals or any other termination issues and all is checked out. Te Utility claims their stuff is OK also. Now, there is the old shop, on a separate service fed from the utility, same chargers, same lights and the only difference is the use of GFCI outlets. The only difference we can establish is the transformer is 60' from the old shop and 220' to the new shop and the utility has a reduced neutral feeding the meter ped. Has anyone ever encountered this before?
tripping GFCI breakers
- Thread starter deltarich
- Start date
- Status
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
Just replying to move post back up in hopes of theories
rippledipple
Member
- Location
- New Jersey
- Occupation
- Electrical contractor
- Occupation
- Licensed Electrician
That exception was removed in '05 or '08. All the other exceptions have been removed and the areas GFI's are required has been expanded.
- Occupation
- Licensed Electrician
I would think if it is not the wiring it's the breakers, if its not the breakers it's the chargers. I don't know why the lights would make a difference.
ramsy
NoFixNoPay Electric
- Location
- LA basin, CA
- Occupation
- Service Electrician 2020 NEC
GFCI breakers may detect momentary imbalance, you can research why later, try a standard breaker with GFCI outlet.
goldstar
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
Fluorescent lighting ? Had a similar problem once. How many light fixtures per circuit ? The situation I had worked fine with one fluorescent. Once we increased to two or more the breaker tripped. Might be some type of electronic noise in the ballasts if that's what you have.
ptonsparky
Tom
- Occupation
- EC - retired
We had a situation where a single floresent fixture would trip a Leviton GFCI device. Changed to a different mfg of GFCI and all was good.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Newer charger designs are sometimes now using PWM outputs, similar to VFDs. The high speed pulses create common mode noise, which if not dealt with circulates in the ground system trying to get back to the source of the noise (the transistors) and gets interpreted by the GFCI as a ground fault. It happens with VFDs too. Some GFCIs do a better job of filtering it out because that noise is at a much much higher frequency than the incoming AC, but it's kind of hit and miss on finding GFCIs that work. We don't see it as much with VFDs because generally they are used on equipment that doesn't need GFCIs, but it is a problem on pool and pond pumps now that VFDs are being added to them.
Shielded Isolation transformers ahead of the units usually does the trick. You can also try adding what are called "common mode chokes" on the DC side of the circuit. Better chargers would (should) include them in the design, but you may have one that doesn't. A call to the charger mfr may be in order and if they don't have them inside, make them recommend one for you.
Shielded Isolation transformers ahead of the units usually does the trick. You can also try adding what are called "common mode chokes" on the DC side of the circuit. Better chargers would (should) include them in the design, but you may have one that doesn't. A call to the charger mfr may be in order and if they don't have them inside, make them recommend one for you.
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