Insulation Resistance Test Procedure

Check the motor frame earth from phase to phase u to e v to e w to e.

Insulation resistance test procedure. Developed early in the 20th century the insulation resistance ir test is the oldest and most widely used test for assessing the quality of insulation. Let s clarify our use of the term current. The minimum test value of motor insulation resistance is 1 meg ohm 1 mh. 1 insulation resistance ir this is the simplest of the tests.

Set the voltage level of the insulation resistance tester to 500v. Insulation resistance decreases in temperature or moisture. Using insulation testing with an instrument such as the fluke 1555 10 kv insulation tester combined with fluke connect technology such leaks can be detected as insulation resistance slowly tapers over time a sign of normal and expected deterioration. Basically there are three different tests that can be done using a megohmmeter.

The test measures the insu lation resistance between the phases and or between phase and ground. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. The insulation resistance test is the second test required by the electrical safety testing standards. The insulation resistance test is an electrical test which uses a certain type and level of voltage 500v d c.

Basically you re applying a voltage specifically a highly regulated stabilized dc voltage across a dielectric measuring the amount of current flowing through that dielectric and then calculating using ohm s law a resistance measurement. For low voltage installations i e. Check full load amps flas with the appropriate meter when the motor is turned on or with a full preference clamp meter unnamed napplet fla. General testing information for single conductor non shielded cable on a reel insulation resistance testing cannot be.

Tests are typically conducted by applying a direct current dc voltage to the conductor under test and measuring the current that flows through insulation called the leakage current and into the non current carrying metal parts of equipment. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. Carried out by applying a dc voltage with a smaller amplitude than for dielectric testing it yields a result expressed in kw mw gw or tw. Insulation resistance testing is a non destructive test procedure.

1 short time or spot reading test. The insulation keeps the current flowing along the wire exactly as intended. What is insulation resistance testing. In other cases tests will detect a more serious issue in the moment when current suddenly drops and returns.

After the required connections are made you apply the test voltage for a period of one min. 230v to measure insulation resistance in ohm s.