vtpower
Electrical
- Jan 8, 2005
- 44
Folks,
I had posted a few weeks ago about a strange phase to phase voltage imbalance measured on the secondary of a three phase 12.47 x 277/480V transformer bank. We recently checked another bank further down the road and have the same issue, 208, 208 and 217. The 480 bank measured 480, 480 and 505.
My new question is, I have been made aware of a practice where the utility will actually roll the primary phases then eventually roll them back (of course watching for rotation on any other three phase banks) and I am curious if anyone has heard of this done for 12KV Distribution? I am willing to try anything at this point because we cannot seem to figure out what is going on.
Thanks in advance for the info.
I had posted a few weeks ago about a strange phase to phase voltage imbalance measured on the secondary of a three phase 12.47 x 277/480V transformer bank. We recently checked another bank further down the road and have the same issue, 208, 208 and 217. The 480 bank measured 480, 480 and 505.
My new question is, I have been made aware of a practice where the utility will actually roll the primary phases then eventually roll them back (of course watching for rotation on any other three phase banks) and I am curious if anyone has heard of this done for 12KV Distribution? I am willing to try anything at this point because we cannot seem to figure out what is going on.
Thanks in advance for the info.