attomsriver
Member
- Location
- New Jersey
I have a 2,000 Amp 460 Volt 3 Phase,Square D disconnect switch
Twice it has tripped on a sensed ground fault of
128 Amps
AS a result of this
It was just serviced and calibrated
The tech produced a 128 Amp signal through the current transformer and it tripped at 128 Amps, on the money
He even changed the ground fault relay/ module
No breakers were ever tripped
my question is that we have six Air conditioning units
with the largest compressor at 460 Volt 3Phase, 7 H.P. ,connected to this switch
we megged 3 of the units so far
this includes the 5 H.P. blower motors and the compressors
So far nothing is out of the ordinary
1) Can a 7H.P. compressor cause a 128 Amp difference in phases to trip this ground fault device ?
2) Is it better to connect a ground fault tester to each component on the AC units?
Twice it has tripped on a sensed ground fault of
128 Amps
AS a result of this
It was just serviced and calibrated
The tech produced a 128 Amp signal through the current transformer and it tripped at 128 Amps, on the money
He even changed the ground fault relay/ module
No breakers were ever tripped
my question is that we have six Air conditioning units
with the largest compressor at 460 Volt 3Phase, 7 H.P. ,connected to this switch
we megged 3 of the units so far
this includes the 5 H.P. blower motors and the compressors
So far nothing is out of the ordinary
1) Can a 7H.P. compressor cause a 128 Amp difference in phases to trip this ground fault device ?
2) Is it better to connect a ground fault tester to each component on the AC units?