Contents
What is hipot test?
The hipot test, derived from the term High Potential Test, is a direct application of a high voltage to a unit under test. The test voltage is usually much higher than the usual operating voltage in order to stress the dielectric properties of the device under test.
What is the difference between a hipot test and an insulation resistance test?
In summary, insulation resistance is typically a field measurement to assess insulation quality. Hipot testing is usually a safety check performed in the factory to verify the product design and manufacturing process.
Where is hipot testing used?
HIPOT tests are very effective in trying to find points or places in the insulating material that have been nicked or crushed, and therefore produce a leakage. Other issues that a proper HIPOT test can identify are stray wire strands, braided shielding, and conductive or corrosive contaminants around the conductors.
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.
How much voltage applied for the hipot test?
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.
How is hipot leakage current calculated?
Using the formula I = 377VC, find the leakage current I (in amps) by multiplying the voltage that your hipot test is conducted at (V) by the capacitance you measured between line and ground (C), and multiplying that product by 377. This will give you the anticipated leakage current I (in amps).
How do you test a hipot tester?
What is the difference between Megger and hipot test?
A megger is a megohmeter, measures insulation resistance. A hipot tester basically works the same way, but measures leakage current. If you see a fault with the megger, you will see a fault with the hipot. The hipot stresses the insulation weak points at higher voltage levels than the megger will.
Can a Y capacitor be tested with a DC hipot tester?
Most safety standards allow the user to disconnect the Y capacitors prior to testing or, alternatively, to use a dc hipot tester. The dc hipot tester would not indicate the failure of a unit even with high Y capacitors because the Y capacitors see the voltage but don’t pass any current.
Can a hipot test be done on an AC circuit?
The test setup and procedures are identical for both ac and dc hipot tests. A minor disadvantage of the ac hipot tester is that if the circuit under test has large values of Y capacitors, then, depending on the current trip setting of the hipot tester, the ac tester could indicate a failure.
Can a capacitor be removed from a Hi Pot test?
You are allowed to remove a Y rated capacitor if its capacitive value alone will cause it to fail hi-pot testing. The MUST pass by DC voltage rating still holds true for high value capacitors, using the rated DC *1.414 method. Small value capacitors MUST pass the AC test per the required standards.
What should the current setting be for a hipot test?
Current Setting for HIPOT Test. Most modern hipot testers allow the user to set the current limit. However, if the actual leakage current of the product is known, then the hipot test current can be predicted. The best way to identify the trip level is to test some product samples and establish an average hipot current.