Sizing the Generator Three Phase Power. Power Generator Formulas www.dieselserviceandsupply.com. Amperage of 3 Ph Generators Amperage (120/208 3-Ph, 80% PF) KW x 1000. Understanding load factor implications for specifYing onsite generators One of the important steps in sizing generator sets for any. And the calculations used. GENERATOR SELECTION. Reduce incoming service size. A voltage drop calculation normally does not.

I concur with Scotty. If your load will vary, you may consider a load controller running multiple sets on an as needed basis. If there will be extended running at below about 25% of rated load, the fuel savings gained by running a smaller set may cover the extra cost of hardware. Common terms are Prime Power and Standby Power.

A Standby rated set will not allow overloads. A prime rated set will allow a 10% overload for one hour out of 24. A 4000 KVA Prime rated set may be the same base model as a 4400 KVA Standby rated set. The basic Standby rated set may have extra options such as an oil cooler and a larger engine sump. You may have warranty issues if you use a Standby rated set in a prime power application. Avery Template 5468 Hawk. I have seen Prime Power sets with the engine over sized an additional 25%.

The reason was to lengthen the time between engine rebuilds. Bill -------------------- 'Why not the best?' Jimmy Carter RE: Diesel Generator Sizing Calculation (Electrical). Thanks Scotty. I did use Caterpillar sizing software and have the results in front of me. I have also done manual calculation but my calculated rating is much less (almost 35%) than CAT results. The idea of writing on this Forum was to get sample of some manual calculation to cross check and finalise the DG Rating.

My Loads are as, Step 1: Transformer Load (Lighting and other small motor loads) - 500 KW Step 2: Motor Load - 550 KW, DOL, Starting Current = 6 times Full Load Current Step 3: Motor Load - 550 KW, DOL, Starting Current = 6 times Full Load Current Spare - 25% (Approx. 400 KW) Running P.F: 0.8 Starting P.F: 0.3 Voltage: 3300 Volts, Frequency: 50 Hz RE: Diesel Generator Sizing Calculation (Electrical) 3 Sep 14 02:53.

I'm not surprised that Cat have given a generator size larger than you calculated. I usually get similar results.