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Correct notation for current Differential Scheme for Auto Transformer

Correct notation for current Differential Scheme for Auto Transformer

Correct notation for current Differential Scheme for Auto Transformer

(OP)
We use 87 to denote bias Differential function.My question is what no is appropriate to denote current differential scheme applied on auto transformer where CTs from HV side , LV side and Neutral point with identical ratio are summed on per phase basis.In my view the no 64R is not appropriate as the scheme will detect both phase and ground faults.

RE: Correct notation for current Differential Scheme for Auto Transformer

It is still a differential and thus still an 87.

RE: Correct notation for current Differential Scheme for Auto Transformer

(OP)
Thanks David and i agree with you but my issue is how do I differentiate between the two as we intent to use both schemes in the same relay

RE: Correct notation for current Differential Scheme for Auto Transformer

Perhaps a 64P for phase fault detection and 64G for ground fault detection?

http://GeneralPAC.com - Awesome video tutorials for power systems PAC!
The Wye Wye Transformer Connection video: http://gpac.link/1GdGRSQ

RE: Correct notation for current Differential Scheme for Auto Transformer

(OP)
doesn't no 64 inherently signifies ground fault?

RE: Correct notation for current Differential Scheme for Auto Transformer

The ANSI Device Number 64 is for ground detector relay

I don't think there is a "phase" detector relay ANSI device number. Otherwise that would make things a little easier. So you'll have to be creative with how you use these device numbers. 64P is a suggestion given the circumstance.

http://GeneralPAC.com - Awesome video tutorials for power systems PAC!
The Wye Wye Transformer Connection video: http://gpac.link/1GdGRSQ

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