All-Pro Hydraulics

Di-Electric Testing

Boom and bucket trucks


Welcome To All-Pro Hydraulics

Serving the hydraulic needs of Eastern North Carolina for more than 35 years.

Di-Electric Testing

Di-electric testing is used to evaluate boom insulation. At All-Pro, we test primarily boom trucks, bucket trucks and transformer reset sticks. When the test is being conducted, a much greater voltage than normal is sent through the booms on the item that is being tested to check for conductivity.

Di-electric testing is a nondestructive way of making sure the insulation will not fail because of insulation degredation from aging, moisture, wear due to vibration or other causes, and to ensure the boom is capable of withstanding surge events such as voltage spikes on power lines which can occur from nearby lightning strikes and other reasons.

During the test, a high voltage, which can range from 60 volts to more than 100,000 DC volts, is applied between two conductors that are supposed to be electrically insulated from each other.

In general, two di-electric test results indicate insulation failure. The first is excessive current flowing during the test due to low insulation resistance of the insulating materials separating the two conductors. The second is an abrupt di-electric breakdown due to electrical arcing or discharge, either through the insulation material, over the surface of the insulation material, or through the air.

Di-electric testing must be conducted on a day which is dry and the temperature, barometric pressure and relative humidity are within the prescribed limits to ensure the accuracy of the testing.