Cable Insulation Resistance Test Values

There is a standard that we can use as a refference for cable insulation resistance test values. The values are approved for international use because these values are from International Electrical Testing Association.

The cable insulation resistance test values give us refference when the insulation of cables is good or not, more than that usually if we work as contractor, the company always need the refference.

Below is table of cable insulation resistance test values according to operating and testing voltage.


Nominal Rating (Volts) Suggested DC Test Voltage Recommended Minimum Insulation Resistance (Mega ohms)
250 500 25
600 1,000 100
1,000 1,000 100
2,500 1,000 500
5,000 2,500 1,500
8,000 2,500 2,500
15,000 2,500 5,000
25,000 5,000 10,000
34,500 5,000 100,000
46,000 and up 5,000 100,000


This is how to read the table above. Let say the wire has operating voltage 250 Volt then we need to test the cable insulation using insulation tester and perform 500 VDC injection between cores and the value shall be at least 25 Mega Ohms of resistant.

The values in the table above is a standard guide so you can use for standarized safety purpose and you can perform your electrical wiring safely without worry of current leakage or short circuit happen during operation that can lead to severe accident.

This article categorized in: Electrical, Engineering, Instrumentation