Phasing Test & equipment for MV Power system
Phasing Test & equipment for MV Power system
(OP)
We have a 13.8KV MAIN1-TIE-MAIN2 Switchgear Fed from Utility's Two, 20MVA, 115KV/13.8KV Delta-Wye Grounded transformers both fed from single utility 115KV line. Upon fault on one of the transformer 13.8KV Bus to MAIN1 breaker we closed the tie breaker.
Question is when we replace the failed 13.8KV bus duct the plant does not want another outage. A colleague is insisting that we should first open the TIE before closing the MAIN1. He thinks that not knowing if the phasing verification was ever done on the two 13.8 KV buses this would be safest approach. I looked at Hubbell-Chance Phase tester see link. http:// www.hubbel lpowersyst ems.com/li neman/mete rs/digital -phasing-t esters.asp
Which tests the phase sequence on both the Transformer (Line) and Bus (Load) side of MAIN1 breaker. I am not sure if this instrument will also identify A B and C buses on both sides of the breaker Can I also use this equipment to measure phase angles between phase As on Line and Load side of the breaker?
Thanks to all my learned colleague.
Question is when we replace the failed 13.8KV bus duct the plant does not want another outage. A colleague is insisting that we should first open the TIE before closing the MAIN1. He thinks that not knowing if the phasing verification was ever done on the two 13.8 KV buses this would be safest approach. I looked at Hubbell-Chance Phase tester see link. http://
Which tests the phase sequence on both the Transformer (Line) and Bus (Load) side of MAIN1 breaker. I am not sure if this instrument will also identify A B and C buses on both sides of the breaker Can I also use this equipment to measure phase angles between phase As on Line and Load side of the breaker?
Thanks to all my learned colleague.






RE: Phasing Test & equipment for MV Power system
Regards
Marmite
RE: Phasing Test & equipment for MV Power system
You need to get both the phase rotation and the sequence right. Relying on instrumentation alone is dangerous.
Rafiq Bulsara
http://www.srengineersct.com