Just found this thread:
http://www.eng-tips.com/viewthread.cfm?qid=255600&page=35
It does answer my questions quite well.
If you have anything to add, I'm all ears (or eyes?).
rgs.
jens
Are PT100 temperature detectors (or other RTDs) used for winding temperature measurements in oil-immersed h.v. transformers (S>10 MVA U>30 kV)?
If so, where are they embedded? What is the temperature gradient between the sensor and the winding (copper surface)?
best regards,
jens
If you are required to have the batteries in a separate room (by your NEC), you should definitely use as much precautions as you can (light switches outside the room, no sockets, explosion proof lights and air suction) no matter what the code says about those things.
The smaller the room (in...
I agree with Muthu,
your motor is running too hot. Does it have a VFD? Are the voltages balanced?
Most of the failure modes of your motor's insulation system are chemical processes with exponential dependency to absolute temperature (according to Arrhenius). The cooler the motor, the longer...
The charger and batteries are connected in parallel, each with it's own protection. You might need to have a fuse for the batteries (they tend to have high short-circuit power).
The charger needs to be "intelligent" in choosing charging voltage and possibly have some alarm functions to inform...
The book pwrengrds suggets has isbne code: ISBN 0-471-44506-1
(it's lying on my desk). I can recommend this one for a text on insulation systems of generators.
For a general text book on synchronous machines, I would suggest "Aternating current machines" by M.G. Say (isbn: ISBN-10: 0470274514...
How about the comparison 60 Mohm primary v.s. 400 Mohm secondary?
The primary has more turns, but the BIL should also be higher, right?
I would question the use of acceptance values for rotating machines used for transformers (especially if liquid filled). The insulation systems are very...
I believe this is a standard function in excitation systems of generators. Also known as "Q-unload" command. It may be used by the control system in "unit stop" sequences. Similar command to governor would be "P-unload", usually commanded at the same time in the stop sequence.
May I suggest measuring the polarization index?
Is it possible to disconnect the core earthing on this transformer (to see if the conductivity is phase-to-core, phase-to-tank or both)?
