Verifying a vt

[veritas]

Hi

How does one actually go about verifying if a vt is suitable for the application at hand? I guess with CT's one grind's through aspects such as burden, kneepoint volts, maximum fault current, etc.

I was asked recently to verify a VT. I considered the total number of relays it feeds and ensured that the VA load was less than the VT rating. Also the VT factor to ensure it is compatible with the system earthing.

What other criteria should be considered to ascertain the suitability of a VT for a particular application?

Thanks.

 

[DTR2011]

Ratio, Polarity, DC Winding Resistance and Some kind of insulation test (DC Megger or AC Power Factor/Tan Delta). If it is oil filled consider testing the oil as well.

 

[veritas]

Ok, thanks smallgreek.

 

[alehman]

Verify the accuracy class is suitable for the application (e.g. metering vs. protection).

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.