Generator Sizing

Your local code should provide a reference for you. If not, check Article 220 of the NEC.

I am, not sure your answer was any help for this question. Not too many people have the NEC hand book handy. The question was answered very well from an India by giving the person the required kVA generator. Actually, I the 200 KV was a lot for a villa. A 350 kVA genset will probably have a 6 cyl diesel engine.

Assuming a power factor of 0.8, the kVA rating of the generator will be 200kW/0.8 = 250kVA.

Generator rating = 250kVA/0.75 = 333.33kVA. The nearest standard rating is 350kVA on the higher end.

The rating of the DG set will be 350kVA (280kW at 0.8pf).

This is a rough calculation. You need to follow the norms applicable to your area while selecting an appropriate genset.

thank you all

jwait55

The point I wanted to make was that either the local code or the NEC gave the criteria to calculate the load in the villa and from that the generator size could be determined. If the villa had a connected load of 200 kw, then the OP must determine what the calculated load will be. You don't take 75% of the 200 kw to size the transformer. The actual load demand may be only 75 kw.

I agree, the connected load +/- should be the determining factor for sizing a stand-by genset. I have a 15kVA Kabota generator which runs my computers & airconditoners & lights. I just calculated the total load in amps & converted to kVA to size my generator. I don't think this is a very complicated calculation as lonf as you know the connected load.

Wareagle quote "the point I wanted to make was that either the local code or the NEC gave the criteria to calculate the load in the villa and from that the generator size could be determined. If the villa had a connected load of 200 kw, then the OP must determine what the calculated load will be. You don't take 75% of the 200 kw to size the transformer. The actual load demand may be only 75 kw."

This should read "you don't take 75% of the 200 kw to size the generator"