What is the Maximum % Operating Load for a Particular Generator

What do you mean by the rating 500kVA-is it standby,prime or continuous?.

Sir,

Please help me first by standby, prime & continuous.

Refer www.catelectricpowerinfo.com/ratings and www.dieselservice and supply.com/generator/faq for standard ratings. Also you should refer "generator sizing"

from Catterpillar or Cummins so that you will consider all aspects(ambient conditions,type of load etc) for proper selection. If you have big motors allowance should be made for starting current. Also fluctuating and periodical loads need care.

Assuming the 500 kva rating is the continuous rating, it can operate indefinitely there. Beyond that, you need to consult the manufacturer's data. It may say something like 10% overload for X period of time, followed by Y period of time at no more than full rating.

If everything is working normally, smoothest operation is likely to be at fairly high load, near or at full rating.

It should say in the User Manual supplied with the equipment.

Gaurav,

The rating you mentioned should be Continuos rating only. In India the Dg sets are specified that way in general. Also in Indian conditions, for a smooth long term operation the DG should be operated at between 80-90 % of load.

You can overload the set for a very short time, but should be avoided as such. The results can be disastrous in high ambient conditions when you have everything stretched to maximum.

Hope it helps

As close to the full load rating as possible.

100%. Any more is called an "overload".

At what % of load the efficiency of the diesel engine is maximum?.