Hi-pot Test & Quality Control
When performing an inspection, a quality control firm will conduct a variety of special quality control tests, depending on the type of product. One of these tests is the Hi-pot test, which is performed when inspecting electrical products. The results from this test are crucial in making sure the quality of your goods is up to your standards. But what exactly is a Hi-pot test?
The Hi-pot test, which stands for high potential, verifies that the insulation of an electrical product is able to protect the user from electrical shock, and assures safety and reliability in finished appliances, cables, circuit boards and motors. During this test, extremely high voltage is applied (much more than during a normal operation) between the conductors and their insulation. The Hi-pot tester (pictured above) monitors the current that flows through the insulation, or the leakage current. The test attempts to illustrate whether or not the product is safe for the user, even when it is subjected to high amounts of voltage. If there is a leakage in the insulation, this can cause the product to break down, and is also extremely dangerous for anyone who would come in contact with a defective product.
This test can help discover design flaws, defects, small gaps between conductive parts and earth, crushed insulation, stray wires, braided shielding, conductive or corrosive contaminates around the conductors, terminal spacing problems, and tolerance errors in IDC cables. There are 3 types of common Hi-pot test:
- Dielectric Breakdown Test– In this test, the voltage is increased until the dielectric fails or breaks down, in order to determine the highest voltage the cable can handle (also called the breakdown voltage). The dielectric is usually destroyed by this test, so this test is used on a random sample basis.
- Dielectric Withstanding Voltage Test- During this test, a standard test voltage is applied; the leakage current is monitored and must be below a preset limit for a required amount of time. This test does not destroy the dielectric, so the inspector can check 100% of the products.
- Insulation Resistance Test- This test is performed in order to determine the resistance value of the product’s insulation. The voltage and the current are used to calculate the resistance of the insulation.
While this test may sound complicated, it is an important part of any inspection that involves electronics, in order to make sure your goods are safe to use.