An insulation resistance tester (commonly called a Megger after a prominent company that manufactures them) is operated by hooking it up to a piece of electrical equipment and running voltage across the insulation on the equipment. The Megger calculates how well the electrical insulation on the equipment is working by checking how much current is flowing between the Megger to the machine. The higher the resistance, the less current will flow, amounting to better electrical insulation shielding. This is important, because poor insulation leads to equipment breaking down.Know More
To test for insulation resistance, make sure to isolate the equipment from any other sources of current. Turn off the equipment, and disconnect it from other components. If it is not possible to completely isolate the equipment, observe what other conducting parts it is connected to, such as cables or wires, and be aware that the insulation resistance rating will be lower than due to these other components. Ground and discharge the equipment to prevent sparks or electrocution both before and after testing.
Attach two leads from the Megger across the equipment's insulation, with one lead on one side and one on the opposite side, and run the voltage on the Megger for at least one minute. The device will calculate the resistance using Ohm's Law and give the resistance rating in megaOhms.Learn more about Electrical
The standard voltage of a home electrical outlet in the United States is 120 volts, although the actual voltage supplied may be as low as 110 volts, due to line conditions. A few appliances, like stoves and electric dryers, may use 240 volts, which require special wiring and outlets.Full Answer >
Test wires, receptacles and other electrical equipment by pressing the tip of the circuit tester to the item to be tested and noting whether the bulb in the handle lights up. If the bulb does not light up, then that electrical piece is not "hot."Full Answer >
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