How to Test a Metal Oxide Varistor

A Metal Oxide Varistor (MOV) is an electronic device that protects an appliance's power supply from voltage spikes and surges in the AC power line. Normally, the MOV has very high electrical resistance. If lightning strikes a nearby power line,the high voltage causes the MOV to become a shunt, preventing the electrical surge from harming sensitive equipment.After this happens, the device's fuse will blow. You can test an MOV(Metal Oxide Varistor) simply by testing its resistance.