current transformers 1

[tonyboy]

which side should p1 face on a ct toward the bus bar or away from the bus bar ? 2/ would you short out ct secondaries when pressure testing ?

 

[DTR2011]

the polarity depends on the application (21 vs 87 vs 51).

#2 If in doubt, short it out. Only 1 short is required per each multi ratio ct (X1-X5)

 

[davidbeach]

Don't fixate of the position of the CT polarity marks. The wye point of the CTs should point toward the protected equipment, the wye point should be grounded (exactly once) and the other end of the CT should be connected to the relay polarity. Wired this way, the relay won't care or notice which way the CT polarity points. Get the CT polarity pointing the "right" direction (what ever that is) but get the wiring wrong and it will never work right. In switchgear, the CT polarity will generally be toward the breaker while free standing breakers will generally have the CT polarity away from the breaker.