Faulty electrical insulation can cause devastating damage to equipment. Measuring the power-factor is done to test the effectiveness of the insulation. Power-factor is the ratio between the capacitive current and the resistive current of an insulator. It measures the effectiveness of the insulator used in transmission lines and other high voltage equipment. Accidents can be prevented if the deteriorating insulator is detected even before it breaks down. Once detected, the insulator can be reconditioned instead of being replaced. This reduces costs on parts replacement. It is necessary to have the right test equipment to detect insulation problems.
A deteriorating insulator can pose serious hazard and can damage other equipment. To test the insulator for power-factor, an alternating current below normal rating is placed on the conductor. While the current is flowing, the dielectric losses are measured. If there is an abnormal reading, special tests like the hot collar test, ungrounded specimen test and hot guard test are done to isolate the problem.
Power-factor testing is used to evaluate the condition of the insulating material. It is done during preventive maintenance or during emergency diagnostics. If you are looking for test equipment, Protec has a complete line of Megger test equipment, like the Megger Insulation Test, for power-factor testing.