1. Disconnect all electrical equipment connected to the test product from the test product cable.

2. Conduct insulation resistance test for each phase of the test cable with Megabyte meter, and only conduct low-frequency voltage resistance test when qualified.

3. Peak test voltage: Umax = 3Uo, where Uo is the cable phase voltage quota value, for example: rated voltage is 10kV cable, single-phase rated voltage Uo = 10÷3kV square root = 5.774kv, so the peak test voltage is Umax = 3Uo = 17.32kv.

4. Test time: set according to the power test requirements.

5. Phase separation test. When the capacitance of the test cable is within the load capacity of the test equipment, the test cable can be connected in parallel with the three-phase conductor and can be tested simultaneously.

6. Connect the test equipment and test cable to the attached special soft connection cable. Turn off the power, set the test frequency, time and voltage, over current protection value and over voltage protection value on the high voltage side, and then start to strengthen the test. During the boost process, the high voltage circuit should be closely monitored, and the test cable should be monitored for abnormal sound. When the test voltage rises, the test time is recorded and the value of the test voltage is read.

7. When the test time is up, the instrument will stop automatically. If no destructive discharge occurs during the test, it will be considered to have passed the pressure test.

8. In the process of boosting and withstand voltage, if abnormal output waveform, abnormal current, unstable voltage, strange smell, smoke, abnormal sound or flame are found in the test cable, the booster shall stop immediately and find out the reason after the machine stops. If these phenomena are caused by the weak insulation layer of the test cable, the withstand voltage test is considered unqualified. If it is determined that the test cable is caused by air humidity or surface dirt, the test cable should be cleaned and dried before testing.

9. During the test, if the non-test cable insulation defect leads to the over-current protection of the instrument, the full-time voltage resistance test shall be conducted again after the cause is found out.