Answer Posted / natarajanramkumar
Tan-Delta also called loss angle OR Dissipation factor
testing is a diagnositic method of testing cables to
determine the quality of the cable insulation.This is done
to try to predict the remaining life expectancy and in
order to prioritize cable replacement and/or injection.It
is also useful for determining what other tests may be
worthwhile.
| Is This Answer Correct ? | 29 Yes | 20 No |
Post New Answer View All Answers
1600kva capacity Transformers how the bucholz relay,Oil temperature,winding,surge relay relays setting are to be done
diff b/w elcb and rccb
i m in need of current rating chart of heavy duty pvc/xlpe, cu/al cables. can somebody provide me? if yes, plz send me at ashish_patel111@yahoo.com
How to test the vector group of a Yd11 transformer? what are the relations to be checked between various vectors to confirm this vector group?
why effective resistance should be more than static resistance in transmission line?
Why can't we parallel the secondary circuits of two voltage transformers?
Why Ac Systems Are Preferred Over Dc Systems?
What is the formula for calculating impedance of transformers connected parallel at fault level 50KA?
what topics we have to concentrate for power grid et.written test.and tell what to read for english synonyms and antonyms.
define reflection method?
why we are not giving the zone 1 trip command to the master trip relay
what is meant by loss of field in a DC motor? how a universal motor works?
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?
What is an ideal transformer?
What is ferro-resonance in electrical system? Why it occurs and what are measures to prevent it?