Answer Posted / meghraj kabdule
Friends Megger is mfg. company which first find out the IR
tester for the measurment of insulation resistance.
| Is This Answer Correct ? | 15 Yes | 31 No |
Post New Answer View All Answers
In the Variable Voltage Variable Frequency Drive, how the Voltage and Frequency varied ? Is it varied in the Inverter part of the Drive ? Please give us supporting document if any.
What is the difference between AC and DC injection methods for rotor earth fault protection
we are having 15kw and 3kw motor both can run in same time , instead of using copper we are using ug aluminium cable , 35 sq.mm is suitable for its current carrying capacity..?
why a tester wont shock while testing the power in house
Why increase in current leads to increase in conductor temperature?
If o/p power is doubled by how much does the sound increase
What is rotating magnetic field?Discuss elaborately.
Why i receive the GCU fault in my DG Sychronization panel . what all the factors considered for this fault .
What is the difference between electronic regulator and ordinary electrical rheostat regulator for fans?
How you give clearance to a spare feeder.
What is thresh hold value of current?
Can 33kva/415v transformer be run underground? If the answer is yes why and if the answer is no why?
what is package substation.how many types they have
What are the advantages & disadvantages of a group electrive drive?
We have drive feeding an output contactor for a 5000 hp motor @ 5kV application. The motor FLA is 629amps x 1.25% service factor = 786.25 amps The cable that we current have in place between the drive and the output contactor is 350kcmil- MV-105 (parallel cables). Per the NEC table 310.60 (C) (69). This show the cable ampacity is at 615 amps per cable for a rating of 1230 amps. We have derated the cable for the cable tray and the multiple cables application and our calculations show that after the correction factor factor we are at 922amps. 1230 amps x .75% correction factor factor = 922.5 amps. The customer is driving us to then use another safety factor of .25% off of the already derated cable. Can you please provide a longhand calculation for your solution on this application?
