Junior Member
Posted December 7, 2017
What shall be the accepted value of contact resistance for Vacuum Circuit Breaker (11KV) ?
What shall be the accepted value of leakage current for VCB (11KV),applied voltage is 18 KV ?
What shall be the accepted value of contact timing ( closing time & opening time) for a VCB (11KV) & what is acceptable limit of closing time & opening time (for the contact) between the phases?
Please also quote the reference standards.
NETA Level III
Posted December 8, 2017
Pro Subscriber
1.) Compare bolted connection resistance values to values of similar connections. Investigate values which deviate from those of similar bolted connections by more than 50 percent of the lowest value.
2.) If no evidence of distress or insulation failure is observed by the end of the total time of voltage application during the dielectric withstand test, the circuit breaker is considered to have passed the test.
3.) For air circuit breakers, contact timing values shall be in accordance with manufacturer’s published data. NETA specs do not call for this test on vacuum.
All standards are based off NETA Section 7.6.3 Circuit Breakers, Vacuum, Medium-Voltage.
Originally Posted by shamimkhan
