0
Values of insulation resistance vary according to the type of insulators and the size of the conducting material inside the insulators, for instance insulation resistance of wires or cables are determined according to type of insulation PVC-PE-XLPE-..... etc and the size of the conductor, and the standard which the wires or cables are designed upon. For example BS 5308 standard states that cables of conductors 0.5, 1, and 1.5 with PVC insulation should have a minimum insulation resistance of 25 Mohm.km . but cables with PE insulation should have a minimum insulation resistance of 5 Gohm.km ...... Now you may realize the difference in IR values. I hope I manage to make it clear image for the answer.
Wiki User
∙ 15y ago
Add your answer:
Earn +20 pts
What is difference between insulation resistance test and polarization index?
Insulation resistance test: This test is used to find the insulation resistance of motor for 1 min or 10 min through high voltage insulation tester. By this we can find the insulation level. Polarization index: This is the ratio between insulation resistance for 10 min to insulation resistance for 1 min.
Why are the insulation resistance values higher for test between phase than between phase and ground?
When testing two cables there is twice the the amount of insulation, as opposed to one cable to ground.
Why multimeter cannot used for measurement of insulation resistance?
Because ordinary ohmmeters are calibrated to measure a range of resistance values that are significantly lower than the resistance of insulation. It should also be realised that we usually test insulation resistance while subjecting the insulation to a high electric field, which a normal ohmmeter is incapable of producing.
What is the difference between an Insulation Resistance Test and a Continuity Test for Electric Cables?
A continuity test checks to ensure that there is no break in the conductors. An insulation test checks to ensure that the insulation is sound.
What type of test should a megohmmeter be used on?
Insulation resistance.
When carrying out an insulation resistance test on a walloven with mineral insulated metal sheathed heating elements the minimum permitted insulation resistance is?
0.1M ohms
What do megger measure?
Megger is usually short for Mega Ohm Meter. It measures high values of resistance with good accuracy. Most often used to test insulation.
Why break down occurs and getting zero insulation resistance when a megger test is performed under vacuum?
The reason why the break down occurs and getting zero insulation resistance when the Megger test is performed under vacuum is because there needs to be a full test voltage performed. Insulation resistance represents the ratio that is between the applied voltage and the leakage.
What are the test for 132 kv cable?
1. phase identification test. 2. Insulation Resistance Test. 3. Conductor capacitance. 4.Conductor Resistance. 4. Outer Sheath Test.
What are the test carry after house wiring?
earth fault impedance test,very important to proper operation of protection system then insulation tests in conduits insulation test of switches resistance test of cables. polarity tests in switches
What test would identify a short circuit in a lighting circuit?
earth continuity insulation resistance polarity
Define the thermal resistance of a cable?
No. Conductor resistance is. Cable insulation resistance to ground is inversely proportional to its length. The longer the cable, the more leakage path to ground; therefore, the lower the insulation resistance to ground.
