Continuing our Spring Series, let’s take a look at what exactly insulation resistance testing is. Every electrical wire, whether it’s in an F-16 cockpit panel, UH-60 circuit breaker, or V-22 wiring harness, is carefully protected with some type of electrical insulation. The wire itself is a conductor of electricity.
The insulation is opposite from the conductor; it should resist current and keep the current on its path along the conductor. The purpose of insulation around a conductor is similar to a water hose carrying water, and Ohm’s Law of Electricity can be more easily understood with a water hose comparison. Pressure on water from a pump causes flow along the hose. If the hose were to spring a leak, you’d waste water and lose water pressure, eventually causing the hose to be destroyed completely. Similar to the loss of water, when there is a problem with the integrity of the insulation of the wire, what results is a loss in the current, affecting the capacity of the aircraft to fly properly. So then, what’s the purpose of insulation resistance testing?
Insulation resistance testing is used as a quality control measurement. The insulation resistance (IR) test (also commonly known as a Megger) is a spot insulation test which uses an applied DC voltage (typically either 250Vdc, 500Vdc or 1,000Vdc for low voltage equipment
We will pose this question to you again…. If your family member or best friend’s life was at stake, would you settle for a company that simply “beeps out” their wiring harnesses and panels, checking only for continuity; or would you prefer a company that performs EXTENSIVE insulation resistance testing on 100% of all electrical wired products, including military and commercial wiring harnesses, aircraft panels, and aerospace circuit breaker panels? We at InterConnect Wiring recommend you not take that risk. Only buy your aircraft wiring harnesses from a company like InterConnect, whose processes REQUIRE extensive testing, 100% of the time, for continuity AND insulation resistance. Click here to see an article about InterConnect Wiring in the Aerospace Testing International Magazine (refer to page 91).