Transformer sequence or differential current...what does this refer to
Transformer sequence or differential current...what does this refer to
(OP)
I notice on a listing of the alarm points on our main transformer that "sequence or differential current" will trip the main. In a nutshell can you explain what this refers to? How do you measure it? And do they usually go together like this?






RE: Transformer sequence or differential current...what does this refer to
------------------------------------------------------------------------
If it is broken, fix it. If it isn't broken, I'll soon fix that.
RE: Transformer sequence or differential current...what does this refer to
RE: Transformer sequence or differential current...what does this refer to
Voltage may get low on an internally faulted phase, but UV protection, if provided, may have longer time delay to avoid nuisance tripping, the differential is generally set sensitive but only when output "current" is not the same as the input, which is much more reliable and faster.
(Btw, differential protection uses CTs only, hence only monitors current, not power.)
I am guessing, but sequence may be referring to overcurrents, e.g. negative sequence for detecting imbalance current , zero sequence for ground fault currents, etc.
Voltage also may n
Rafiq Bulsara
http://www.srengineersct.com