4.1 220/380V Three-phase electrical motor

Our tips to choose your single or three-phase electric motor

The first specification to know about is the voltage: is it single-phase or three-phase? Single-phase motors are generally used for domestic power supply, in private households (example: electrical outlets at home). Three-phase (3 x 400 V) is more common in the industrial sector, for big energy-consuming machines.

To choose your electric motor, it is necessary to know the needs of your machine:  on the motor nameplate, look for the power in kW (kilowatt) necessary for the proper functioning of the machine. Then, you need to know about the rotation speed, which is a multiple of the number of motor pole pairs:

2P (2 pairs of poles): 3,000 RPM, 4P: 1,500 RPM, 6P: 1,000 RPM, 8P: 750 RPM.

For the same power, the more pole pairs a motor has, the bigger it is and the slower it runs (base speed: 50 Hz).

Examples of applications: car lift, wood working machine, tyre changer, conveyor, shredder, pump...

Characteristics and calculation of three-phase motor power

An electric motor transforms the electrical energy in mechanical energy. Motors are supplied by a single-phase voltage (1-phase + 1 neutral) or a three-phase voltage (3 phases).

To operate your machine, 4 main criteria need to be considered when choosing your three-phase electric motor:  

-          The motor power: from 0.37 kW to 315 kW. 1 HP (Horsepower) = 0.746 Kw

-          The rotation speed: 750 RPM (8 poles), 1,000 RPM (6 poles), 1,500 RPM (4 poles) or 3,000 RPM (2 poles)

-          The mounting system: B3 (foot mounted), B5 (plain holes flange) or B14 (tapped holes flange).

-          The shaft height sets the dimensional characteristics of the electric motor according to the IEC standard (56, 63,71,80,90,100,112,132,160,180...)

EASI-Spare motors also have an IP55 protection rating: they are protected against dust infiltration and water jets.

Discover our range of 220V single-phase motors as well as our variable frequency drives.