We have a client metered on 11kV. From the breaker, the client has a breaker which switches on a 1.5MVA transformer on to a 415V bus.
The client has a power factor correction capacitor bank of 500KVA and the loading is mostly inductive.
The client has been complaining of high voltages between...
Hallo guys,
need help on the 7RW6000 undervoltage relay. Can this relay be connected on the delta side of a Star/Delta transformer to detect eartfaults in the transformer when the Delta side autorecloser is open.
Regards,
Punglu
We have undertaken studies on the cause of flashing on a yellow phase spout. The latest having destroyed the 11kV indoor CB. The CB was installed for a client whose load is mostly compressors, airconditioners and freezers. What could be the likely causes and what remedies do you suggest. This is...
How long should the last relay on the attached drawing (At the 33kV source Bus)take to initiate a trip to opening of the breaker?
I am trying to grade and give the customer (11 kV incomer breaker)some appreciable margin. Any standards used, may be in other utilities. Let me know please and...
We have a gen set consisting of a 5oo MVA generator and a 0.415/11 kV Traffo. The generator has Xd'= 15.9 %, Xd''= 11.1 %. The Traffo has z = 4.58%. I have calculated the fault level but its too high.
May be there is something I have forgotten and please remind me which of the generator...
Hallo guys,
A new gen set was installed to supply an isolated station. Apparently there is a radio installation for the police in the area and they are complaining of interference since the new gen set was installed.
How valid is the claim and how do I go about ascertaining whether the gen set...
What type of RS232 cable does the DIGSI 4.0 use to commicate to siprotec 7UT612:
.Null modem with loop back handshaking
.Null modem without handshaking
.Null modem with partial handshaking
.Null modem with full handshaking
We are installing a 7.5 MVA TX under a tight schedule and REF scheme is included in the design. The following are the details:
An LV CT- 400/1A class Px, 15 VA, Vk >= 250V, Imag<= 30mA at Vk/2. Another neutral CT has ratio of 400/1A and is of clas Px, 15VA.
Other available CTs are:
LV line CTs...
We have three CTs on a feeder rated 400/1, 36 kV. The CT on one phase failed and we can't get one urgently. We have one rated 200/1, 36 kV. Is it possible to use the 200/1 in conjuction with the others considering that the relays are electromechanical on which the plug settings can be adjusted.
We recently replaced an 11kV aurocloser with a smrc type of autorecloser having an R6 controller. All the pre-commissioning tests were ok but when we put it into service it tripped on an earth-fault.
I decided to disable the ground fault and closed the bypass swith. There were currents of 100A...
We have four feeders radiating from a 33/11 kV substation. When one of the feeders trip on earth fault, one of the others also trips on earthfault.Their relays have the same settings. What do you think could be the problem and what is the solution?
I have to test the mentioned relay that was manufactured by BBC. I am not well versed with distance relays and the relay seems to have never been tested since commissioning, more than 8 years ago!
My boss insists we have to come up with a method to test the relay urgently since the outage for...
I am atteneding to a break-down on the differential relay(Duobias-M)for a 33kV/11kV Transformer. Existing CTs are of ration 200/1 and 600/1. I have DDT relays for use as regards the emergency. Is it possible to use the DDT relays without using interposing CTs, given that I don't have the ICTs at...
