1. The accessible bare conductors of motors, electric heaters and electric actuators must be grounded (PE) or connected to zero (PEN).
2. The insulation resistance of the motor, electric heater and electric actuator should be greater than 0.5MΩ.
3. For motors above 100kW, the DC resistance value of each phase should be measured, and the mutual difference should not be greater than 2% of the minimum value; for motors without a neutral point, the DC resistance value between the lines should be measured, and the mutual difference should not be greater than 1 of the minimum value. %.
