When I say all routine tests have benn carried out, I refer to:
Temp Rise
Lightning impulse
24hr leakage
Voltage withstand
Over voltage withstand
Winding resistance measurement
Voltage ratio and vector measurement
No load loss and current measurement
Short circuit impedance measurement
I am...
Hello
How important is it for a PD test to be carried out on a drytype transformer (11kv/400V)? Is it a nice to have or is it critical?
All other routine tests have been carried out ok.
The second question is, in order to convert a balanced volatge unit protection scheme to a circulating current scheme, it is just a case of changing the relays and uncrossing the pilots?
Hello,
I have an 11kV substation that utilises Unit and O/C protection and has 6 ring feeders.
The unit protection used a mixture of Tranlsay H and SDP relays.
the relays are being replaced throughout with MBCis. If there is a pilot fault, will the MBCis initiate a trip at both end of the...
hello, can someone please advise the basics of bus zone protection on 11kV 3ph AC switchgear?
As far as I understand a CT on the bus riser (next to bus coupler) for an O/C relay is sufficient. is this correct?
So for an 11Kv 3ph distribution ring, with all cables protected with translay SDP 101, I could:
Open relevent circuit breaker at my end, open remote CB at other end of cable to create open circuit status (hence isolating the cable but it will be floating, and not earthed)
Inject AC volts...
Hi, can anyone please advise on how to measure Mag curnves on class X protection CT's. what is physically required. Do you require isolation of the cable or can it be done by secondary injection testing?
Thanks
Hi,
I am just wondering, since electicity always tries to return to the souce via the path of least resistance, what happens to it once it has returned to the source?
Is it just a case of all the electons loosing their charge?
Sorry if its a stupid question?
