What size generator do I need for 3hp compressor?

Strictly speaking 3hp will be a 3kw, but no way will a small 3kw generator cope with a big electric motor starting current. I’d think you’d want at least double the capacity ie 6kw.

What size 3 phase generator do I need?

For a three-phase generator, the full load current is calculated as I = 1000 × S / (√3 × V). Where, S is the generator rating in kilo-volt-ampere (kVA), and V is the generator rated voltage in volt (V). For a single-phase generator, the full load current is calculated as: I = 1000 × S / V.

What size generator do I need to run a 3HP motor?

A generator rated 3 kVA will run a 3 hp motor. The engine that drives the generator may be rated 4 hp. If the motor load is hard starting, then you might need a larger generator, 4–5 kVA. Usually generators are rated in kilowatts, so a 3kW generator could be large enough, 4kW will work ok in most all cases.

What kVA generator do I need to run a motor?

The Full load input of the motor assuming an efficiency of 80\% and a power factor of 0.8 lag the KVA input at FL = 20 x 0.75 / (0.8 x 0.8) = 23.44 KVA. If the motor is started with FL on the shaft and a starter to limit the starting current, may be you will require about 40 to 45 KVA generator.

How much kVA do I need for a 20hp motor?

When motor is operating, after start, requirement will be 1kva for 1hp i.e. 20hp – 20kva used when running. Amps available on a generator per phase = kva x 1.39. i.e. 20kva = 28amps/phase over 3 phases. NPE provides these calculators and guides to assist with general queries and recommends working with experts to ensure suitability.

How many amps does it take to run a 20kva generator?

Note 3 – A dummy load or extra load will need to be applied to avoid glazing once running. When motor is operating, after start, requirement will be 1kva for 1hp i.e. 20hp – 20kva used when running. Amps available on a generator per phase = kva x 1.39. i.e. 20kva = 28amps/phase over 3 phases.