What is DC Hipot testing?
A dielectric strength test, commonly called a hipot test, dielectric withstand, or high potential, is a stress test of the insulation of a device under test (DUT). Such a test applies a voltage to the DUT that is much higher than normal operating voltage; typically 1000V AC plus twice the normal operating voltage.
What is the standard for Hipot test?
Tests of Used Motors: For proof tests of of used motors, the standards stipulates that an AC voltage Hipot test ranging from 125% to 150% of the rated RMS line-to-line voltage, equivalent to about 65% to 75% of 2E+1000 V, has proven to be adequate.
How do you perform a Hipot test?
Attach the high voltage lead to one of the isolated circuit phase conductors. Switch on the HIPOT Tester. Set the meter to 1000 Volts or pre decide DC Voltage. Push the “Test” button on the meter and after one minute observe the resistance reading.
Is DC hipot destructive?
One advantage of the DC Hipot test is the following: Although the test voltage can be high, the energy available to be discharged as an arc is small. Thus, arcs from a DC Hipot test are not destructive if the test is done properly.
What is the allowable leakage current during hipot test?
Looking at the 120-kΩ rule of thumb, when testing is performed at 1,000 V and the tester is adjusted so that breakdown occurs if the resistance of the product is less than 120 kΩ then the maximum allowable leakage current would be 8.333 mA (1,000 V/120,000 Ω = 8.333 mA).
What is acceptable leakage current?
To provide a margin of safety for the consumer, regulatory agencies usually require that a product exhibit a line voltage leakage current of less than 0.5mA. With some products equipped with 3-prong plugs and warning stickers, the permissible leakage current may be as high as 0.75mA, but the typical limit is 0.5mA.
Can high voltage damage cables?
There is no evidence that damage occurs to a cable subjected to higher voltages if a breakdown does not happen. However, if a DWV failure (breakdown) does occur, the energy is limited so that the risk of damage is low.
Why DC is used in Megger not AC?
If we apply DC voltage then as we know Capacitor blocks the flow of DC, only leakage current due to imperfection of insulator will flow and hence the Resistance measured by Megger will actually represent Insulation Resistance. This is the reason, an Insulation Tester or Megger have DC voltage generator.
What is total DC current of Megger?
Working Principle of Megger 500 Volt DC is sufficient for performing test on equipment range up to 440 Volts. 1000 V to 5000 V is used for testing for high voltage electrical systems. Deflecting coil or current coil connected in series and allows flowing the electric current taken by the circuit being tested.
Why do we use DC for a cable Hipot test?
Since the dc is free of capacitive division, it is more effective in picking out mechanical damage as well as inclusions or areas in the dielectric which have lower resistance. Carrying out High Voltage or High Potential (Hi-Pot) DC testing on XLPE insulated cables has a tendency to ‘polarize’ the insulation.
How safe is your hipot tester?
Cirris hipot testers are designed to be as safe as practically possible. Injuries from hipot test equipment are very rare. Still, not every hipot test situation is safe. There are always things you can do to increase the safety and reduce the risk a hipot test might present.
What is the difference between a hipot test and a Megger test?
Both instruments are used to check the quality of insulation. The Megger test is usually non-destructive because the voltage levels used are at or below the equipment ratings, while the Hipot tests are usually destructive, for the opposite reason.
Why do we do Hipot test?
About Hipot Testers: A hipot tester (hi pot tester or hy-pot tester) is used to perform electrical safety tests on electrical components and products. The hipot test (along with dielectric withstand tests) ensures that the unit under test (UUT) meets operator safety requirements and meets the standards set forth by UL, CSA, IEC ,…