The one min interval is an industry practice that allows everyone to take the reading at the same time.
Insulation resistance test low reading.
Ca 1954 diacam2 equipped with a 160 x 120 detector and a 38 x28 wide angle lens the ca 1954 camera is ideal for all applications in the building electrical maintenance and mechanical maintenance sectors.
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.
Step 3 if the megger reads a resistance under 1 1 000 ohms on your meter after the initial 60 second interval the cable has failed and the cable should be removed.
With a little record keeping and common sense however you can get a good picture of the insulation condition from values that are only relative.
Insulation resistance decreases in temperature or moisture.
The insulation resistance test consists in measuring the insulation resistance of a.
For low voltage installations i e.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
During the measurement and immediately afterwards some of the terminals carry dangerous voltages and must not be touched.
1 insulation resistance ir this is the simplest of the tests.
The insulation resistance test is the second test required by the electrical safety testing standards.
After the required connections are made you apply the test voltage for a period of one min.
Smaller systems will remain steady because the capacitive and absorption currents drop to zero faster than on larger systems.
Dc voltage of 500 or 1000 v is applied between the windings and the ground of the motor.
Larger insulation systems will show a steady decrease.
Damaged or contaminated insulation will will mask absorption with current leakage keeping resistance low identifying a potential problem.
After 1 min you should read and record the resistance value.
The measurement of insulation resistance is carried out by means of a megohmmeter high resistance range ohmmeter this is how the test works.
The insulation resistance test is an electrical test which uses a certain type and level of voltage 500v d c.
230v to measure insulation resistance in ohm s.
