Test specification for insulation test of rotor coil for asynchronous motor:

　　1, all the tests are one minute, and the so-called one minute is that the test should start from a voltage of no more than 1/3 of the voltage, gradually rise to the full value of the test voltage without more than 5% each time, and when the test voltage rises from its half value to the full value, the allowable time should not be less than l0 seconds, and then the total voltage should be kept one point. After a long time, it dropped to full value 1/3 and opened.

　　2. the test voltage should be AC, and the cycle rate is about 50 cycle and the actual sine wave.

　　3. when testing part or phase of the coil, all the untested parts of the coil must be grounded.

　　4. when the coil is completed, the length of all metal leaves (copper or aluminum foil) is longer than that of the core length by 10 millimeters (3000 volts and below) when the individual coil is tested.

　　5. the insulation resistance must be measured before the last high voltage test. After the insulation resistance grid is checked, the withstand voltage test will be carried out again.