We have 132kV GIS switchgear with outgoing cables connnected. The cable needs to be tested at HV AC at 75kV. The voltage transformer is a fixed type above the cable box. Disconnecting mean are provided inside the cable box, but degassing would be required to remove that link.
Should the GIS be...
Hello Everyone
Im conducting a research on major cause of failure of power transformers nowadays. In this regard we are looking for failed power transformer equal or above 100MVA,132kV preferably in Europe or Asia, Did anyone come across such a case. I would be very greatful for the leads in...
We have a circuit breaker with 110DC spring charging motor. It is to be used in a switchboard where the the supply is 220VAC. Can we use an industrial type converter (220Vac-110Vdc) of suitable rating to supply power to the charging motor,instead of replacing the motor itself.
thanks in advance...
Does anyone know of any company(apart from Reyrolle Pacific Switchgear.Newzeland) involved in providing maintenance services on Reyrolle's LMT2 type switchgear. The maintenance work involves 11kV bus bar including replacement of all shrouds, Monoblocks & thorough fare Bushings for all panels...
What are the advantage and disadvantage of having a Generator Circuit Breaker between the Generator and Transformer. In some installations I noticed a GCB is not used and the generator is directly connected to the transformer.
Thanks in advance for your valuable feedback
What are the standards or criteria for selection of CT primary rating for a motor feeder? If motor full load current is 40A, can I use a 40/1 CT OR the CT has to be rated higher say 50/1 or 60/1?? Let me know the guidelines please. If 40/1 CT cannot or should not be used, what are the...
Hi Everyone.
Is it advisable to use a portable PD measurement system that can analyse PD in live conditions on 13.8kV Switchgear which is hardly 3 years into service.The Switchgear is installed in an airconditioned room.OR is it advisable to install a viewing window on busbar, cable and breaker...
Hi Guys
Could anybody list standard tests for Life assesment of 11kV Air Insulated switchgear which is about 10 yrs old considering no maintenance has been carried out so far.What kind of test equipment would be required to carry out those tests.Would it be necessary to do mechanical endurance...
In a substation 132/33/11kV, the SC rating of 33kV CB (MOCBs) is 31.5kA. The client is being proposed replacement with vacuum CBs rated 25kA considering the fact that the neutral point on the 33kV side is isolated and grounded by 17 Ohm reactor.
Is it advisable to use the 25kA CB instead of the...
I needed some expert comments that is why im sharing this information.
There is a product in the market called intelligent light information system. It is installed in the switchgear in busbar compartments and individually in each CB compartment to protect from internal arc.The smallest of arcs...
Is it a good idea to promote to a customer on site tests which are normally done during FAT, at the midlife of a Switchgear. The tests could be Timing, speed, sychrocity and bounce.
What is the advantage of having CTs on both sides of an outgoing feeder compared to CT on outgoing only with common CTs for busbar protection on the bus section.
Thanks in advance for help.
Dear All
Our client have 36kV current transformers in the switchgear.Due to some airconditioning issues, there was moisture discovered in the cable section.The CTs had visible signs of oxidation and paths of corona discharge.They tested for insulation resistance of primary winding with respect...
Hi
Can anybody point out any article on this subject. I have come to learn that Heat shrink cable termination is no longer recommended in Medium voltage switchgear(1000V to 52kV).Instead cold-shrink termination is recommended.
The reason being when heat shrink termination is applied, over the...
Hi Everyone
We are facing a problem of moisture occurance in 33kV air insulated switchgear in the cable compartment.Is it ok to leave silica gel bag in the compartment to absorb moisture.
Thanks to answer the question.
Cheers
Im looking for Operation and Maintenance manuals for the following circuit breakers.
1-Mitsubishi
10-VPR-25B-Vacuum Circuit breaker
2-Merlin Gerin
DSE-65 Solenare
Merlin Gerin-Grenoble France.
Can anybody tell me where I can find them.Ive tried their websites but since these are obsolete...
My client is asking for tests on a 400kV VT.The tests includes magnetizing curve for the VT.Can anyone tell me how its done as I have never encountered such request before.
Thanks to all for help.
Can anyone tell me in general what is this standard is about? Its related to Medium voltage switchgear I believe.Does it also gives the degree of protection required for the switchgear e.g IP4xx
Thanks for the help
A 3.3kV,3 pole,107A vacuum contactor feeding a motor is to be converted to a transformer feeder feeding 1000kVA 3.3kV/0.415kV Transformer.
In addition to some wiring modification and replacement of protection relay from motor protection to O/C and E/F relay as recommended by the manufacturer.Is...
