How to measure motor resistance with a multimeter
First, disconnect the power supply, disconnect the power cord, and adjust the multimeter to the Ω position. If the motor is connected in a star shape, one test lead is connected to the star point, and the other test lead is used to measure the ABC three-phase windings respectively, and the resistance value is obtained; if it is For a delta-connected motor, remove the connection and measure the head and tail of the three phases respectively, using the above method.
The main thing is to roughly measure the unbalance of the resistance between the terminals, and to check whether there is a short circuit between the terminals and the casing.
When measuring the resistance of the motor winding, it is necessary to use a bridge to measure it, because the resistance of the winding is very small, and it is generally inaccurate to measure with a multimeter.
When measuring the phase-to-phase insulation or phase-to-ground insulation of the motor, a megohmmeter should be used, and the insulation should not be less than 0.5 megohm.
If you want to measure the ground insulation of the motor, you should use a megohmmeter to measure it. The low-voltage motor is measured with a 500V megohmmeter, and the measurement value is not less than 0.5 megohm. 2500V megohmmeter to measure, the measured value should not be lower than 1 megohm/KV;
