Wire Cable Insulation Resistance Test Values

This type of test is a go no go type of test and is to determine if the insulation has been damaged during installation.

Wire cable insulation resistance test values.

Even when not required by the end customer many wire and cable manufacturers use the insulation resistance test to track their insulation manufacturing processes and. 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. Also acceptable values of insulation resistance depend upon the equipment you re testing. Curve a shows test values as measured.

Insulation resistance testing of low voltage cables in the field. Curve b shows same values corrected to 20 c see page 22 giving a definite downward. You perform this insulation resistance test on the cable and record the data on a copy of the attached form. Historically many field electricians use the somewhat arbitrary standard of 1 megohm per kv.

For a good cable you will see results similar to those on the following page. Values based on ieee std 43 2013. You have a single conductor 500 kcmil 15kv cable. If during periodical testing insulation resistance of cable is found between 5 and 1 mω km at buried temperature the subject cable should be programmed for replacement.

Ansi neta mts 2015 table 100 11 insulation resistance test values rotating machinery for one minute at 40 c. Since 80 of electrical maintenance and testing. A rated line to line voltage for three phase ac machines line to ground voltage for single phase machines and rated direct voltage for dc machines or field windings. If insulation resistance of the cable is found between 1000 and 100 kω km at buried temperature the subject cable should be replaced urgently within a year.

The results obtained from ir test are not intended to be useful in finding localized defects in the insulation as in a true hipot test but rather give information on the quality of the bulk material used as the insulation. The results obtained from ir test are not intended to be useful in finding localized defects in the insulation as in a true hipot test but rather give information on the quality of the bulk material used as the insulation. Figure 4 typical record of insulation resistance of a mill motor. The resistance values will increase over time due to capacitive and insulation charging.

Wire and cable manufacturers use the insulation resistance test to track their insulation manufacturing processes and. B kv is the rated machine terminal to terminal voltage. The international electrical testing association neta specification maintenance testing specifications for electrical power distribution equipment and.