dch921
Member
- Location
- United States
The place I work we have a pair of 480/208 3 phase transformers delta-wye. These are tied together with a tie switch in case of failure of one of the transformers. Current have loads of 300+ amps on one and 150+ on the other(secondary sides).
We have come to find high current on the main grounds that are bonded to the secondary neutrals.
Transformer 1 has around 40amps on its ground and #2 has 60amps on its ground.
From our main panels on each transformer to the tie switch panel we have around 10 amps on each ground. From the tie switch grounds to each transformer is where we are seeing the high current.
So far have not been able to find any ground fault issues and not even sure how long this have been a problem. Only started looking into it after seeing neutrals that would spark off to ground. Any ideas or help would be great
We have come to find high current on the main grounds that are bonded to the secondary neutrals.
Transformer 1 has around 40amps on its ground and #2 has 60amps on its ground.
From our main panels on each transformer to the tie switch panel we have around 10 amps on each ground. From the tie switch grounds to each transformer is where we are seeing the high current.
So far have not been able to find any ground fault issues and not even sure how long this have been a problem. Only started looking into it after seeing neutrals that would spark off to ground. Any ideas or help would be great