There is no mention of allowable leakage current magnitude in this case.
It is a Go / No-Go test, meaning whether the switchgear failed or passed the test. That's all.
"....what is acceptable leakage current for power frequency voltage test?
or how much should be the maximum leakage current? .... "
1. The " power frequency withstand voltage test -Ud:50kv for 1 min ...." is the high voltage Dielectric withstand voltage test.
1.1 This test may be conducted in power frequency or direct current.
2. The pass or fail is based on the DUT withstood the voltage without breakdown for the duration per the product standard. For Ur=24kV the Ud is 50kV 1 min. The leakage current value is NOT required to be recorded/reported in the test report.
Info: For this reason, some simple/basic dielectric test sets are not equipped with the leakage mA meter and timer.
Che Kuan Yau (Singapore)
The leakage current for AC HV tests depends on the capacitance of the windings, which varies from machine to machine or transformer to transformer and hence no standards specify any limits.
But in the same machine, all three phases, when tested individually shall have nearly the same leakage current. If there is a wide difference of leakage currents between phases, then the windings are suspect.
