Thứ Tư, 5 tháng 9, 2018

Useful Facts About Hipot Tester

By Paul Olson


The term hipot is usually used as an abbreviation for high potential. It is a term that is used to refer to a certain class of electrical safety testing instruments referred to as a hipot tester. These instruments are used in the verification of the electrical insulation in finished cables, appliances, and other wired assemblies. Such assemblies include electric motors, transformers, and printed circuit boards just to mention a few.

In many cases, after the assembling/manufacturing of an appliance/product some current leakage of some level occurs. The interior of the product contains internal capacitance and voltages that often cause this minimal current leakage. It is normal for all devices to experience this leakage. However, in some scenarios, the current leakage may too high that it should be due to certain reasons.

Faults in the design or disintegration of product insulation among many other reasons may be the cause of the excessive leakage. These flaws often cause excessive leaking of current and may give rise to electrical shock for any individual that comes into contact with the defective appliance. The essence of a hipot test is to ensure and verify that the product has enough insulation so that the user of the device may not be electrocuted.

Another name used to refer to hipot test is Dielectric Withstanding Voltage (DWV). During this test, a high voltage is applied between the metallic shielding of the product and its current-carrying conductors. When this is done, there will be a resultant current that flows through the insulation. This current is known as leakage current and a high potential tester is used to monitor it.

One major assumption is made in hipot testing. The assumption is that by applying excessive voltage, the insulation of the product should break, and if it does not, then the device should work fine under normal conditions. The appliance is supposed to be resilient against normal voltage, which is often applied in ordinary everyday use of most devices. It is this assumption that gives rise to the name Dielectric Withstanding Voltage.

The objective during testing is to stress the insulation in the product. However, apart from inducing stress on insulation, the test detects any workmanship defects that may be present. The workmanship monitoring focuses on the tiny gap spaces occurring between the earth ground and conductors that carry current in the device. In normal working environment, these small gaps can be closed by dirt, humidity, vibration, shock, or contaminants.

The flow of current is allowed when the small gaps between earth ground and current-carrying conductors in electrical devices. This may cause a major electrical risk that must be rectified during manufacture before the product is made available on the market. Only DWV can be used for defect detection. Other methods may not be efficient like the DWV even though they can attempt to identify these defects.

A high potential tester is simply and electric device that manufacturers use to verify electrical insulation. It is comprised of a high-voltage source, current meter, and a switching matrix. The matrix is used to connect current meter and voltage source to all contact points in a cable. The testing process may be automated by the inclusion of a microcontroller and display.




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