A30 amp breaker means the pump is smaller than 2 hp will use ~13 amps/2300 watts during operation and will require a 4 KW internally regulated generator to operate the pump. (This size breaker is also used for 1.5 HP pumps which require a 3 KW internally regulated generator for proper pump operation.) 75 kW to Amps Conversion (7.5 kilowatts to ampere, kW to amps) - MyCalcu. Conversion. ForSingle Phase AC: Current (A) = 1000 * Power (kW) / (Power Factor * Voltage (V)) For Three Phase AC (Line to Line Voltage): Current (A) = 1000 * Power Toconvert 3-phase kVA (kilovolt-ampere) to amps (amperes), you need to know the line-to-line voltage (VL-L) of the 3-phase circuit and the power factor (PF). You can use the formula: Amps = (kVA × 1000) / (√3 × VL-L × PF). For example, if the line-to-line voltage is 240 volts, the power factor is 0.8, and the 3-phase kVA is 15, then the Lineto line voltage I (A) = 1000 x S (kVA) / (√3 x V L-L (V)), which means that the phase current in amps is calculated by multiplying 1000 by the apparent power in kilovolt-amps dividing the result by the square root of three multiplied by the line to line voltage RMS in volts Line to Neutral Voltage I (A) = 1000 x S (kVA) / (3 x V L-N (V Asingle phase input invertor would be around £600 I would guess. Single 230v phase input/3 phase 230v output connected to the compressor. So it would have to be able to be connected in delta. A little design of the run signal and it should be OK. Only issue is the 8kW or so input, around 30 odd amp. I(A) = 1000 x P (kW) / (3 x PF x V L-N (V)). It means that the phase current in amps is calculated by multiplying 1000 by the power in kilowatts dividing the answer by three Asa "rules of thumb" amps horsepower rating can be estimated to. 115 volts motor - single-phase : 14 amps/hp; 230 volts motor - single-phase : 7 amps/hp; 230 volts motor - 3-phase : 2.5 amps/hp; 460 volts motor - 3-phase : 1.25 amps/hp; Always check nameplate information before designing protective devices, wiring and switch gear. tojNw7.