CT Polarity check

Electrical Testing Talk
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1

I have a job coming up where currently on the PLC it shows the current as reading correctly as well as the Voltage however the power is registering as a negative reading. I figure the cts on the breaker could be swapped backwords or it is wired in correctly. The ct wiring is in a Y configuration coming from the breaker to the control panel to the relay. I was thinking about swapping the wiring at the shorting blocks untill i realized its wired in Y at the breaker in the yard.

Im not guru when it comes to protection relays I work mostly testing aparatus. What is the best way to mitigate this issue and how would I check polaritys at the relay?

2

At first glance it appears your CT is flipped. Sometimes you can reverse the polarity in the software but if not you need to physically rotate it. There are usually arrow indicators on the CT that show which direction the current flow is. If you have a system with a Neural, remember that CT will flow opposite of the phases. Hope this helps.

3

So I was on site today and looked at the phasers through the hmi and noticed the current and voltage phasers are out to lunch. Voltage vectors are as follows Vab 0* Vbc -120 Vca -240
Current: ia -95.1 ib -334.4 ic 215.0

Seems like something is flipped.