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GFCI circuit breaker trips after UPS or SurgeArrest

Issue:
GFI circuit breaker trips after UPS or SurgeArrest is connected.

Product Line:
Back-UPS Models ES,CS,NS,XS and RS. Surge Surpressors; All Product Families

Environment:
Surge or Back-UPS plugged in to GFCI outlet.

Cause:
A ground fault interrupter (GFI) is a safety device required by the National
Electrical Code. Its purpose is to avert personal injury.
Some GFI devices are poorly calibrated and trip prematurely.

Resolution:
You can try to replace the GFI device and see if this solves the problem.
Try a different brand if possible. If the outlet is not in a bathroom or kitchen, you can consider changing the circuit to a non-GFI receptacle or breaker. The circuit breaker type GFI devices are generally of higher quality and are recommended as being more immune to this type of problem.

There are thousands of successful installations of UPS and computer equipment with GFIs.



Background:

Ground fault interrupters come in two forms: mounted in a wall receptacle or

mounted in the circuit breaker panel. The ones in the wall receptacles can be

seen in any hotel bathroom and can be identified because they have a small

""reset"" button on them (usually colored red). The ones in the circuit breaker

panel look similar to regular circuit breakers, with the exception that they

too have a small ""reset"" button.



A ground fault interrupter senses any leakage current to ground on the circuit

into which it is connected. Its function is to detect any currents which might

occur as a result of, say dropping a hair dryer into a bathtub. Such currents

could potentially fatally harm someone but not be large enough to trip the

circuit breaker on overcurrent.



GFI devices are typically installed in kitchen and bathroom areas, but

sometimes they are used throughout a facility or home.



UPS systems and computer equipment exhibit leakage currents. These currents

are a natural result of the common mode filters present in computers and UPSs.

These leakage currents may be large enough to ""fool"" the GFI and cause it to

trip. When this happens the UPS will go to battery because the GFI will cut

power to the UPS or computer. The UPS passes the cumulative leakage current of

all of the connected loads back to the GFI device."

 
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