High Potential Testing

High Potential Testing (Hipot) is a high voltage test that ensures “good isolation.” Also known as Dielectric Withstand Test, a hipot test guarantees that no current will flow from any point to another.

The hipot test is a high-voltage test that is non-destructive and establishes the adequacy of electrical insulation for the regularly occurring over-voltage transient. It is used for all devices for a designated time to determine that the insulation is not marginal.

Circuits Central possesses the equipment and knowledge to perform these specific tests at our facility as part of the manufacturing process or on their own for debugging or certification purposes.

High Potential Testing Method

Before any hipot tests are conducted, it is essential to follow the correct procedures. Be sure to consider the following steps:

Disconnect all equipment from the cable circuit. That way, you will prevent any damage and interruptions as a result of flashovers or trip-outs due to leakage. Equipment includes items like transformers, taps, motors, switches, and more.

Ensure there is enough clearance (approximately 2.5 feet) between the ends of the circuit test and all grounded objects, or other equipment not being tested.

Lastly, for circuit conductors not under the test, ground them. This includes cable shields and any equipment nearby.

It is important to note that this type of testing is the most dangerous of any maintenance testing, but one of the most vital. That’s why it needs to be conducted by a qualified professional trained in using this equipment, like the team at Circuits Central.

Common Tests

While hipot testing is needed under specific safety regulations, it also serves as an excellent non-destructive test that determines the adequacy of electrical insulation in devices. Here are the most common tests used:

Dielectric Withstanding Test

A dielectric withstanding test is an electronic assessment used on a product as a way to analyze the efficiency of its insulation. This test can be between insulated sections of energized parts and electrical ground. A dielectric withstanding test will also qualify a device’s capability of safe operation.

If it is determined that there is a current running through a product that is lower than the specified time limit required, then it will pass dielectric withstand requirements. This type of test is also used for factory tests on new equipment, or for apparatuses already functioning.

Insulation Resistance Test

An insulation resistance test identifies insulation deterioration immediately so that any further damage can be stopped. As soon as it is created, insulation is already aging. When it undergoes aging, its performance is not as strong. Deterioration can occur quicker in installation environments that have extreme temperatures or contamination with chemicals. As a result, hazardous conditions can develop and compromise the safety of its personnel.

Since determining insulation deterioration is essential, the insulation resistance test is a simple one to implement. A technician will use average voltage to the insulation, as a way to measure the current. Then, Ohm’s Law calculation is implemented (divide the voltage by current to discover what the resistance is). A typical amount for insulator resistance is millions of ohms.

Dielectric Breakdown Test

The dielectric breakdown test is the final test where the technician will use high voltage to the electrical components. By doing so, they will be able to measure the voltage where the insulation breaks down and starts conducting electricity (the breakdown voltage). The reason this test is so crucial to perform is that the information documented is especially useful for users, designers, and technicians. A designer will use the data from this test for the redesign or repackaging process for insulation. It also allows them to keep the dielectric breakdown in mind and insulation resistance values on the sheet that contains component specifications.

To find out more about how we initiate the dielectric breakdown test, get in touch with one of our informative team members. They will explain how the process works and how it can be implemented for your specific business. Give us a call at 1 (888) 821-7746, fill out our contact form, or send us an email at info@circuits-central.com.