3PH Transformer Open Phase Detection
3PH Transformer Open Phase Detection
(OP)
I need some advice. Looking at a hospital complex with a mix of 3 phase DY, YY, and YD transformers (not sure of the exact numbers of different types of transformers yet).
Hospital has installed wye type voltage magnitude sensors on utility interconnect end to detect single phase loss.
During test of single phase loss (utility pulled open a fuse), backfeed from the hospital complex kept these voltage sensors picked up, so they didn't detect a single phase loss.
My question, does the voltage angle change on the backfeed from the hospital system after a phase loss? Also, could we detect that with a negative sequence voltage element?
Any comments would be appreciated. I'm starting to hear of several cases where the voltage magnitude sensors on UG cable boots have not picked up for a loss of phase.
Hospital has installed wye type voltage magnitude sensors on utility interconnect end to detect single phase loss.
During test of single phase loss (utility pulled open a fuse), backfeed from the hospital complex kept these voltage sensors picked up, so they didn't detect a single phase loss.
My question, does the voltage angle change on the backfeed from the hospital system after a phase loss? Also, could we detect that with a negative sequence voltage element?
Any comments would be appreciated. I'm starting to hear of several cases where the voltage magnitude sensors on UG cable boots have not picked up for a loss of phase.






RE: 3PH Transformer Open Phase Detection
https://
Registration might be required.
RE: 3PH Transformer Open Phase Detection
RE: 3PH Transformer Open Phase Detection
RE: 3PH Transformer Open Phase Detection
RE: 3PH Transformer Open Phase Detection
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: 3PH Transformer Open Phase Detection
RE: 3PH Transformer Open Phase Detection
RE: 3PH Transformer Open Phase Detection
The other 1/4 of the load is stepped down through a DYg transformer to 13.2kV.
The main backup generation is only used in an islanding mode. There are other small gensets, but they are strictly for backup mode.