measuring 460 volt phase balance
measuring 460 volt phase balance
(OP)
I asked that a customer measure voltage and amps for each phase. A reply came back that it is "too dangerous." I do not have any plant control layout yet, but I think it is common to have current sensors on the lower voltage side of some transformers for general control room monitoring. I was thinking if all 3 phases have such measurement points, I could encourage them to get amp readings there.
Any words of advice?
thanks,
Dan T
Any words of advice?
thanks,
Dan T





RE: measuring 460 volt phase balance
Rafiq Bulsara
http://www.srengineersct.com
RE: measuring 460 volt phase balance
If it's a new installation you might also have the option to pull information from an electronic tripping unit if the incomer is an ACB. Not an option with fuses though!
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: measuring 460 volt phase balance
Muthu
www.edison.co.in
RE: measuring 460 volt phase balance
For the higher voltage motors the bus has PT's where we can monitor voltage, and opening the load center cubicle door provides easy access to the CT secondary signals at input to the relays.
For the lower voltage motors, there is no CT or PT so we have to find some place to clamp on to 480vac cable... either in the energized MCC/Load center or in an energized motor term box. None of these is to be taken lightly.
=====================================
Eng-tips forums: The best place on the web for engineering discussions.
RE: measuring 460 volt phase balance
Rafiq Bulsara
http://www.srengineersct.com
RE: measuring 460 volt phase balance
RE: measuring 460 volt phase balance
Certainly I am not privy to with much detail, but comments similar to Thedroids have been repeated by others having far more direct relevant experience than I. Like, Those qualified and certified and otherwise allowed if not encouraged to play with Medium voltage (4160) are reportedly on-staff and in-house at all times.
Qualified doesn't get too far unaccompanied by willing, and Q and W sometimes aren't even in the same room, especially when the request comes in 4th hand.
RE: measuring 460 volt phase balance
As far a qualifed and willing - a foreman once told me - "we've got old electricians and bold electricians. But we do not have any old bold electricians."
David Castor
www.cvoes.com
RE: measuring 460 volt phase balance