How to estimate the HP of an AC traction motor basing on continous rating when V rms and I rms along with RPM has given
Revised later to correct my own confused reading of the question. It is not clear what the given values represent. Is the current a measured value under operating conditions or a value given as the rated current? You can not accurately calculate the rated or actual output power without the efficiency and power factor. You can not even estimate the actual output power without knowing the rated output power. The power factor at rated load will be similar to efficiency estimated for various power ranges in another answer. At less than rated load, power factor and efficiency are less that they are at full load with zero efficiency and nearly zero power factor at no load. If the given current is the rated current, the input is 1500 X 200 X 1.73 = 519 KVA. If you estimate the efficiency and power factor at 0.95 and 0.85, 519 X .94 X .83 = 419 kW output or 419/0.746 = 562 Hp. The best way to estimate rated power from rated current is to look in motor catalogs and match up the current rating with a listing for a similar motor. Catalog data is also useful for accurate estimation of actual load power from actual load current. Re further details: The above paragraph gives an estimate calculation based on continuous ratings for voltage and amps based on 3-phase RMS values. If you know standard power ratings for the type of motor, estimate based on the standard power value nearest to the calculation results; for example 500, 550 or 600 Hp.
