Difference between CT class 5L400 & C400
Difference between CT class 5L400 & C400
(OP)
Dear Members,
Please anybody tell me about the difference between the CT class 5L400 & C400
Please anybody tell me about the difference between the CT class 5L400 & C400






RE: Difference between CT class 5L400 & C400
See page 106 for ASA Accuracy Classifications
The letter L stands for low internal secondary impedance, which is a characteristic of bushing-type CTs having completely distributed secondary windings or of window type having two to four secondary coils with low secondary leakage reactance. The number before the letter is the maximum specified ratio error in percent (= 100IRCF Ð 1I), and the number after the letter is the maximum specified secondary
terminal voltage at which the specified ratio error may exist, for a secondary current of 20
times rated.
RE: Difference between CT class 5L400 & C400
K classification shall have a knee-point voltage of at least 70 percent of the secondary terminal voltage rating see IEEE C57.15 for further info.
RE: Difference between CT class 5L400 & C400
C400 (IEEE) means 10% allowable error up to 20 times rated current into a 4 ohm burden.
20 x 5A x 4ohm = 400V
In practice, there is no appreciable performance difference.