Voltage readings today....
- Thread starter Mule
- Start date
- Status
- Location
- Massachusetts
Real example, we had a customer with a 208Y/120 4000 amp service, they added a lot of 480 volt refrigeration equipment, I have no idea why not 208.
Anyway we installed two large 208 delta to 480 delta transformers. To leave them ungrounded delta would require fault indication. Fine but no one would be there to fix it if there was a indicator. It will at some point become an accidentally grounded system.
Strahan
Senior Member
- Location
- Watsontown, PA
No but many ungrounded delta's. And it is amazing we have all the proper fault indicators installed many that are showing faults but try convincing management that this needs taken care of. There reply is well everything is still working fine. Yea I bet these guys are the same guys who keep driving there car when the oil light comes on.:wink:
Someone, your immediate supervisor or the highest authority (electrical superintendent?), whoever it may be, needs to find where the problem is, present this case to the management, and convince them of the problem, what could happen, and what repairs needed. It will only work fine for so long.
Strahan
Senior Member
- Location
- Watsontown, PA
Yes agreed and this is already being addressed with management, but it still bafles me that it takes such a convincing agrument to convince them there is a problem. Once again it leads back to the problem of not having any electrical knowledge at the managment positions yea its crazy.
Cold Fusion
Senior Member
- Location
- way north
All right. Always a good day when I learn something new. I'll have to change my statement from: "I never seen a POCO installed, ungrounded 480V delta." to: "I've never seen a POCO installed ungrounded 480V delta. But I've heard of one. "
I've seen plenty of customer owned 480V ungrounded delta, but never overhead - outdoor. However, I'll bet someone has an example of one of those too.
I think the POCOs don't like them (ungrounded delta, especially outdoor, overhead) because of lightning events destroying the xfm. The lightning arrestors connected to the line side of the main were a clue that it could have been ungrounded delta.
"think" means that I am generally clueless about some (or most) POCO reasoning
cf
We installed a new lighting arrester, and new conductors and raceway from the meter can to the starter cabinet......The lighting arrester was definitely smoked.......However afterwards I checked the line side of the meter socket and found 150k to ground from phases to ground.....opened up B phase at the weather head and the problem appears to be in the service drop and/or the transformer bank, not the riser......called poco....they said "you cant read it to ground, because its not a grounded system" I said "Oh yea?" Something is bleeding through somewhere......
I said "Oh yea?" Something is bleeding through somewhere......Is that 150k as in ohms? Maybe 250.36 applies?
- Status