Hello,
I have an offshore installation with an 11kV bus, like this:
- Five 11kV generators connected to the 11kV switchboard, 4nos 2.7MW and 1no 4.2MW, installed at different time.
- All generator neutrals are brought to a switching (contactor) panel so that only one neutral is grounded.
-...
I am studying reliability of an old installation and I am asking the client a question on why all four 415V generator sets have their neutrals solidly grounded(3 sets in normal operation).
Can you give me opinions on whether there is a way to mitigate the flow of unbalanced current through the...
I have a 13years MV induction motor(8-poles) driving a reciprocating nitrogen compressor. The HP nitrogen are stored in "bullets" for safety purging/inerting system and pressurising cooling water system, both are for plant emergency shutdowns or trips.
Leaks in N2 or cooling water systems lead...
I have a difficult situation at this moment whereby a 6.6kV 3.1MW(FLC=320A) is needed to operate at a current just beyond 320A and upto 325A. This motor is driving a gas compressor. Unusual fluctuation of gas composition (increase in nitrogen content) lead to this higher load.
This motor has...
I have an old chilled water cooling coil which need to be replace and I am thinking of increasing the capacity slightly. Which of the following choice is better:
1. Increase no. of rows of cooling tubes(present 4 rows)
2. Increase no. of fins (present 12fpi)?
I ask this question because we are using European voltage in our country but America made diesel engine driven generator having 50Hz 2x110Vac source is very common here.
According to the manual, the 2x110Vac supply source can be connected in series to give 1x220Vac single-phase output with the...
I had 2 DC motors,from same manufacturer and installed at the same time, found with wrong labels for Armature winding(terminals A & F) and Field winding (terminals J & K).
These motors runs from 110Vdc battery banks and applied as emergency lub oil pumps. During the commissioning, we did not...
Friends, can you suggest what portable instrument is suitable for measuring air-flow rate in a duct?
Somebody tells me that a single point measurement in the centre of the duct is not a correct figure because the air speed is not uniform in a duct.
For an old duct, I can foresee problem...
