If the t/f capacity is 500KvA then what is Amps ratting of
the main breaker.

Answer Posted / athar abid

As we Know that

KVA = Sqrt 3 . Voltage(V) . Current(I)

Now for 400V (Phase-Phase) syayem

I = 500KVA/(1.732 * 400)
=500*1000/(1.732*400)
=721.7 Amps

There is no standard breaker available with this rating, so
take one step above rating i.e. 800Amps

Hope its clear.

Regards
Athar Abid

Is This Answer Correct ?    1 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

How the circuit breaker is selected for Induction motor of 100 kW, 415 volt, 0.85 power factor, 0.95 efficiency ?

1218


What is stacking factor? What is its approximate value?

785


why actual valve timing diagram is different than ideal valve timing digram of a 4 stroke engine?

5051


how do u gauge the size of the cable ?for eg. consider a 300 sqmm L.T Cable.How do u determine the size of the cable seeing it pratically?

1653


what is meant by 3rd hormonics ?

1398






Why we used 690V in ACS 800 drives.Why dont use standard voltage like 415v or 1.1Kv

1922


With a phasor diagram show the effect of increasing the field current of a generator supplying a constant real power and connected to a grid system.

1507


Pl.brief me any electrical major fault you have rectified.

1489


what is lrs tank water resistance.

2072


how to calculate transformer turn primary & secondary side 11kv to 420v

1776


In how we connect watt meter for open & short circuit test of a single phase transformer.

5632


with help of neat sketch explain principle of TIG welding process

1451


Explain the method to keep noises low in a control system?

653


tan delta equation test on alternators

1769


why the NGR (neutral grounding resistor) always OFF during DG off?

3069