subject: Dielectric Voltage Stand Up To Check Of Electrical Products [print this page] Dielectric voltage withstand check is demanded in nearly every security standard of electrical safety tester products, for dielectric voltage stand up to check is really a vital component of security standard of electrical items. Dielectric voltage stand up to test will be the so-called higher voltage check which happens to be a test to determine whether or not the insulating materials and spatial distances adhere to the standard by giving a voltage which happens to be higher compared to the rated voltage to the equipments for certain time.
Check Method
one. Check if the main power change in the hipot tester is OFF.
2. Except for the special design in the equipment, all the other conductive metal parts really should be well grounded.
3. Connect all the wires or terminals at the energy input end in the measured equipment.
4. Close all the energy switches and relays, etc.
5. Set the tested voltage of the hipot tester to zero.
6. Connect the higher voltage transmission line (generally red) to the energy input end in the measured equipment.
7. Connect the loop grounding line (generally black) towards the accessible conductive metal part in the measured equipment.
8. Close the main energy change of the hipot tester and raise the secondary voltage of the hipot tester to the desired value slowly. Usually, the raise speed of voltage must be kept below 500V/sec.
9. Maintain this testing voltage within the time specified.
10. Lower the testing voltage slowly.
11. Disconnect the main energy switch of the hipot tester. First disconnect the high voltage transmission line and then the loop grounding line.
The following cases show that the measured equipment fails the check:
The testing voltage cannot be raised towards the desired voltage value or it lowers instead.
There may be warning signal on the hipot tester.
It needs to be noticed that we ought to be extremely careful because there may be higher voltage which happens to be danger for human body existing in the dielectric voltage stand up to test.
Cases that can make the equipment free from factory dielectric voltage stand up to check.
The energy input of the items will be the ELV or SELV in the secondary output of other items, such as power supply and transformer.
The merchandise will use alternative power supply as component, and this energy supply is identified by CSA, of complete case and input and output connector. For it's identified by CSA, this energy supply has passed the dielectric voltage withstand check. Therefore, we can consider relieving it from dielectric voltage withstand check. Nonetheless, we have to check whether the energy supply is damaged before it is installed.
When the signal transformer is applied within the circuit of same voltage, and it's not the safety device, we can consider relieving the component from the start towards the iron core from dielectric voltage withstand test.
Matters that must be paid specially attention to:
It must be specified that only trained and authorized personnel can come into the check zone and operate the equipment.
Fixed eye-catching warning signals ought to be set around the test zone to keep other people from the danger area.
During the check, all the personnel, including the operators, must keep distance with the hipot tester and measured equipment.
When the tester is started, the output line should not be touched by anyone.
