Cable Insulation Resistance Test Standard

The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.

Cable insulation resistance test standard.

Insulation resistance test. Cables for rated voltages of 1 kv um 1 2 kv and 3 kv um 3 6 kv reference number. The measured resistance has to be higher than the indicated limit from the international standards. 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.

Insulation resistance decreases in temperature or moisture. 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. When overpotential testing cable its common practice to conduct the insulation resistance measurement first and then proceed with the dc overpotential test if acceptable readings are achieved. 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.

The insulation resistance test consists in measuring the insulation resistance of a device under test while phase and neutral are short circuited together. Since 1989 revised editions of the acceptance testing specifications have been published in 1991 1995 1999 2003 and 2007. The insulation resistance test is the second test required by the electrical safety testing standards. Since 80 of electrical maintenance and testing.

Hands down without a doubt one of the most universally searched topics on ec m s website from a historical perspective is insulation resistance testing as a result some of our most popular evergreen articles like understanding insulation resistance testing continue to top the charts when it comes to most popular content. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. 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. On february 19 2009 the american national standards institute approved the neta acceptance testing.

Principle of insulation testing and influencing factors insulation resistance measurement is based on ohm s law. Insulation resistance testing is a non destructive test procedure. Insulation resistance testing purpose. Also acceptable values of insulation resistance depend upon the equipment you re testing.

Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv. Ieee400 1 2007 ieee guide for field testing of laminated dielectric shielded power cable systems. The document uses the standard numbering system of ansi and ieee.