phase angle error limits for a C800 as per IEEE 1

[MULU007]

Hi Everyone,
I wanted to know the phase angle error limits for a C800 as per IEEE standard.
BCT type CT, primary 345kV, secondary 34.5kV for transformer
some test sheet values from SAT as below. Trying to ascertain if the value is acceptable.

1. CT is 600:5, 34.5kv side, phase angle error is +3.22 degrees.
2. CT is 1200:5, 345kv side, phase angle error is +8.76 degrees.
3. CT is 1200:5, 345kv side, phase angle error is +11.16 degrees.
4. CT is 600:5, 34.5kv side, phase angle error is +7.18 degrees.

The phase angle test values for the remaining CTs are less than 1 degrees

 

[scottf]

IEEE C57.13 does not give phase-angle error limits for CTs with only a protection rating, like C800.

The standard calls for factor testing at rated current and at rated burden and gives a ratio error limit of 3% (except for low-ratio window-type CTs, where 3% ratio error can be exceeded).

Are the test results you listed at nominal rated current and what burden is applied?

Are you sure the phase-angle error in degrees and not minutes?

 

[MULU007]

Hi Scott,
Thanks for the reply. Yes, the % ratio error of any of the CT is not exceeding 3%, actual test values are in the range of 0.05%. I guess the ratio error is what is to be checked.
I only have test sheet and a CT excitation plot so unable to determine if the test is done at nominal rated current and what the burden is.
and yes, the phase angle error is in degree.
Thanks again for your thoughts.