The insulation resistance tester under UHV power can help many power workers conduct various power tests more conveniently.

The most basic insulation index of a circuit. The handover test of low-voltage electrical appliances should ensure that the insulation resistance of motors, distribution equipment, and distribution lines at room temperature is not less than 0.5M Ω (for equipment and lines in operation, the insulation resistance should not be less than 0.5M Ω). 1M Ω/kV). The insulation resistance of low-voltage electrical appliances, their connecting cables, and secondary circuits should generally not be less than 1M Ω; In relatively humid environments, the insulation resistance should not be less than 0.5M Ω; The insulation resistance of the secondary circuit small busbar should not be lower than 10M Ω. The insulation resistance of Class I handheld electric tools shall not be less than 2M Ω.

Insulation resistance: The resistance corresponding to the leakage current flowing through a dielectric after a certain period of polarization process when a direct current voltage is applied to the dielectric is called insulation resistance.

Insulation resistance testing standard

1、 Insulation resistance test of high-voltage distribution equipment

1) The insulation resistance of the active part shall be tested with a 2500V vibrometer and shall not be less than 1M Ω.

2) The insulation resistance of the high-voltage main circuit shall not be less than 250M Ω.

2、 AC motor insulation test

1) The rated voltage of the stator is above 1000V, measured with a 2500V vibration table. The stator resistance is not less than 1M Ω, and the rotor resistance is not less than 0.5M Ω.

2) When the rated voltage of the stator is below 1000V, measure it with a 1000V vibration table, and the insulation value should not be less than 0.5M Ω.

3) When the rated voltage of the stator is below 500V, measure it with a 500V vibration table, and the insulation value should not be less than 0.5M Ω.

3、 Insulation resistance test after communication motor maintenance

1) After maintenance, measure the insulation resistance between the winding phase and phase to ground of the motor. For motors below 500V, the insulation resistance after repair shall not be less than 1M Ω, and for motors above 500V, the insulation resistance of the winding after repair shall not be less than 5M Ω.

4、 Cable insulation resistance test

1) The insulation resistance of newly installed cables should not be less than 50M Ω;

2) During operation, the insulation resistance of high-voltage cables should not be less than 2 M Ω, and low-voltage cables should not be less than 0.5 M Ω.

3) When measuring the insulation resistance of cables, the power supply and load side should be disconnected. After the measurement is completed, the cable is discharged in three phases to the ground.