Why is insulation test necessary?
Insulation is subject to many elements that can cause it to perform at a less-than-acceptable level. Excessive heat or cold, moisture, vibration, dirt, oil, and corrosive vapors can all contribute to deterioration. For this reason, routine insulation testing is necessary.
Why do we check the insulation resistance of a cable?
Insulation resistance testing is a key test for electrical cables as it is a measure of how effectively the cable is insulated. Poor insulation may result in short circuit, electric shock or fire.
What is insulation tester used for?
Insulation testers use a high voltage, low current DC charge to measure the resistance within wires and motor windings to identify current leakage and faulty or damaged insulation, which can lead to arc faults, blown circuits, and risk of electrical shock or fire.
How important is insulation resistance testing?
Insulation resistance or IR test is a very important maintenance procedure to check out the integrity or health of an electrical system . If the insulation resistance is found high, we can say an equipment or system is fine otherwise its not.
What is the minimum acceptable insulation resistance?
Perform the insulation resistance test between conductors at a reduced test voltage of 250 V DC. However, where this option is used, the minimum acceptable insulation resistance remains 1 MΩ .
How does a Megger test measure insulation resistance?
A megger is an electrical measuring instrument, it can be used to measure the insulation resistance. A megger has a DC generator and an ohmmeter in it. A normal ohm meter cannot be used to measure high resistance values, so in that case, we can use a megger or megohmmeter. With the help of a megger, we can measure the electrical leakage of a wire and it is done by passing an electric current through the wire for a certain period of time.
What is the function of an insulation tester?
Portable insulation resistance testers and megohmmeters are designed to help prevent hazards such as electric shock and short-circuits caused when the insulation in electrical devices, parts, and equipment used in industrial plants, buildings, and other settings degrades over long periods of use.