Why Is “Leakage Current” Testing of 3 Phase Equipment required?
The following sentence in the Standard is often not understood: “If the equipment must be energised to close or operate a switching device, then a leakage current test shall be performed”. For example, various types of controls, contactors and relays are switching devices that must be powered on (or energized) to latch them (switch them on). Therefore, on many 3 phase appliances, if you can’t bypass such internal switching devices with an insulation tester probe or manually latch them, it is impossible to perform a thorough insulation resistance (IR) test. To do so thoroughly in order to comply with legal requirements may at best, be very time consuming. What-is-more, performing an insulation resistance (IR) test at the power plug of such 3 phase devices with an Appliance Tester or Insulation Tester which cannot perform a “Leakage Current test” (or “Run/Live test”), will only test up to the contactors and relays and not show any safety faults inside the actual appliance at all!. Any su
