IEEE C57-13-2-2005 pdf free download – IEEE Standard Conformance Test Procedure for Instrument Transformers.
6. Treatment of failures within test sequence
Failures occiuring during conformance testing should be evaluated, and eon’ections should be made befoie any re-testing is carried out A design change made to a transformer to correct a fiuilure within a test sequence shall be evaluated for its effect on any preceding sequence.
7. Tests
Conformance tests shall consist of the following tests performed in the sequence shown on each transformer selected t’or tests.
7.1 Impulse tests
Impulse tests shall be made as specified in 8.8.5 of IEEE Std (57.13 and at the test levels indicated fiw the transformer [IlL in Table 2 of IEEE Ski C57.13-1993.
7.2 Voltage withstand tests
Voltage withstand test-s of pnnsary windings to grounded secondary windings and pans, including metallic case, frame, base, nameplate. mounting facilities, and the core (if accessible), shall be made as specified hi 88,3 oflEEli Std (57.13-1993 and the values indicated in Table 2 of IEEE Ski (5713-1993.
7.3 Accuracy
7.3.1 Metering accuracy of current transformers
Metering accuracy test shall he made per 81 of IEEE Std (57.13.1993. The transirrners shall he demagnetized and then tested at l(13c. and 100% of rated primary current and with a pnmary current equal to the rated current multiplied by the continuous thermal current rating factor Tests shall be made with the minimum and maxinaim standard metering burdens for which the manufacturer assigns the same metering accuracy class.
In the case of dual ratio and multi.ratui cransSorrner, test. shall be made to verify the accuracy at all ratios assigned accuracy ratings by the manufacturer and to veriI, the ratio of each tap.
7.3.2 Relaying accuracy of current transformers
Relay accuracy classes assigned by the manufacturer shall be verified in 7.32.1 and 7.32.2.
7.3.2.1 Transformers assigned “C” classification
a) Check ratio per 8.1 ofIEEEStdC57.13-1993.
hI Measure resistance of the secondary winding.
c) Test excitation current per 8.3.2 of IEEE Std (57.13-1993.
dl Using data from (hI and (c). calculate relay accuracy per 8,110 of IEEE Sid (57.13.1993 to verify that the transformers meets the requirements of 6.4 of IEEE Ski (57.13-1993.
7.3.22 Transformers assIgned ‘1” classifIcation
These transformers shall be tested per LI of IEEE Std (‘57.13-1993 to serif that the relay accuracy wquirenwnts of 6.4 of IEEE SW (‘57.13-1993 are met.
7.3.3 Accuracy of voltage transformers
The translirnners shall he tested at 90% and 100% of rated voltage with mm burden and at 110% of rated voltage at the maximum burden for which an accuracy claaa is assigned by the manufacturer. Accuracy at other burdens may he detennined by test orby calculation, as specilied in 8.1.12 of lF.EE .5W (‘57.13-1993.
The accuracy at 90% and 110% of the rated voltage at any burden maybe detennincd by applying the ratio and phase angle difTerentiats detennincd in the zero burden test to the accuracy for that burden at 100% of rated voltage.
7.4 Temperature rise
7.4.1 Temperature rise—current transformers
Each transformer shall be tested with a primary current equal to the rated current multiplied by the
continuous thermal current rating factor. The temperature raw tests shall he made in accordance with 8.7 of
IEEE Std (‘57.13-1993. and the temperature rise for continuous operation shall not exceed the limits us
Table 4 of IEEE SW (‘57.13-1993.
In case of a dual ratio or multi-ratio trans former, the temperature tests should he made at the primary rating that produces the greatest teanperattar rise.
7A.2 Temperature rise—voltage transformers
Each voltage transformer shall be tested with 100% of rated pnmaty voltage at the thermal burden rating assigned by the manufacturer. The temperature rise tests shall he made in accordance with 8.7 of IEEE Std (‘57. l3-1993 and the ternpcratuir rise fur continuous operation shall not exceed the limits specified in Table 4 of IFFE Sid (‘$7.13- 1993.
In the case of a dual ratio or muiii’rat.o transfiinner, the temperature tests should be made at the primary rating that produces the greatest temperature rise.IEEE C57-13-2 pdf download.