Cable Insulation Resistance Test Standard

Regular testing of the insulation on an installation or machine is therefore a useful way of monitoring this type of deterioration so you can act before total failure occurs.

Cable insulation resistance test standard.

Also acceptable values of insulation resistance depend upon the equipment you re testing. Cables for rated voltages of 1 kv um 1 2 kv and 3 kv um 3 6 kv reference number. Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv. Since 80 of electrical maintenance and testing.

Insulation resistance decreases in temperature or moisture. Principle of insulation testing and influencing factors insulation resistance measurement is based on ohm s law. 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. Insulation resistance testing purpose. Insulation resistance test. The insulation resistance test consists in measuring the insulation resistance of a device under test while phase and neutral are short circuited together.

Power cables with extruded insulation and their accessories for rated voltages from 1 kv um 1 2 kv up to 30 kv um 36 kv part 1. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. Since 1989 revised editions of the acceptance testing specifications have been published in 1991 1995 1999 2003 and 2007. Ieee400 1 2007 ieee guide for field testing of laminated dielectric shielded power cable systems.

The measured resistance has to be higher than the indicated limit from the international standards. On february 19 2009 the american national standards institute approved the neta acceptance testing. 11 ieee 400 2012 omnibus ieee guide for field testing and evaluation of the insulation of shielded power cable systems rated 5 kv and above. 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.

The document uses the standard numbering system of ansi and ieee. Insulation resistance testing is a non destructive test procedure. After dc overpotential test is completed the insulation resistance test is done again to assure that the cable has not been damaged by the hi pot.