Search results for query: *

What is the crieteria of performing the DC Leakage Test on the stator or rotor of 13.8 Kv, 100 Mva generator that has run over 100,000 hrs? Why it is considered harmful for the winding insulation? If we don't perform this test or Hipot test then how we can evaluate the condition of insulation of...

There are basically two type of problems with these breakers. The operating mechanism of the Magne-blast C.B and the arch-chutes. The operating mechanism is so much complicated and conjusted that you hardly have space to perform maintenance of parts like cams, bearings, rollers etc. These parts...

Thanx a lot for your resposes. I conclude that its only the temperature which is concerned in this regard. This, anyway is always a consideration on the new machines as well. Regards to all.

Is there any limits or change in the capability (curve) of the older generators. In other words is there any limit for the MVAR output of the generators. If so, what is the correction factor to find out the new Limits of the MVAR.

Yes! there many tests which can be done but first of all one must know the problem as faced during operation of this transformer. I mean whether it was tripped on some transformer protection operation etc. etc. Only then we can see what tests can be performed to evaluate its condition.

I think we are going in too much chemistry. If the generator is in-situ and I have the facility to make barring or put on turning gear I would alter the turning gear controls to make the turning of shaft for about 5-10 minutes after every 48 hours and keep the space heaters ON. Thats it. Please...

21 A without load is ok. As a rough estimate the No-load current should be < 1/3rd of the FLC.

The generator space heaters should be ON all the times. Ideally speaking,if it is a bigger generator I mean 5 Mva or more, then we should consider giving a quarter turn to the shaft after 2 - 3 days. For that we must have a prper lubrication system. However, we had a break-down/fire in the...

Generally : Total weight of such a transformer s (approx)=70,200 Kg Transfer weight without oil =48,500 Kg Transfer weight with oil= 66,200 Kg However it all depands on the manufacturer. But this can give you an idea.

Measure the current on each phase while operating in either direction. It will give the clear picture of the happenings.

Perfect. I understand. Thank U very much indeed.

Thanx for the response. It speaks that one having 4% droop will p.u more load as compare to the unit having 5%. I conclude that reverse i.e. the shedding of load is also true with regards to the droop setting? If thats right then can we say that the p.u or shedding off the load is inversly...

If number of gas-turbine generating units having same capacity but set to different speed droop setting i.e. 4% and 5% are running and connected to large system. Upon sudden demand of load (due to the tripping of larger unit on the system) how the load will be picked up on these units keeping in...

Is it technically possible to replace a 3-windings power transformer (2-primary LV & 1-secondary HV) 200 MVA, 13.8/13.8/132 Kv, 5.6% impedence with identical rating transformer having 11.4% impedene.