LV Cable meggaring

[alanElec]

I have 4 runs of single core 630 mm2 cable running between AMF panel and Feeder pillar..The feeder pillar side cable is not terminated while it is already terminated in the AMF Panel.I want to meggar these cables.Should I open the termination at AMF panel side before meggaring?
Or si it good if the breaker is in OFF position?

Also if I am using a voltage of 500 V for testing, what are the typical values to be obtained ..?

 

[ScottyUK]

The breaker, locked in the open position, should adequate for your tests. If this is a new installation the IR value 'should' greater than your 500V megger can measure. Your local code will state an acceptable minimum, but if your readings are down that low then you need to investigate the reason.

 

[alanElec]

thanks a lot..between will a 1000 v dc be sufficient for the test..my knowledge is normal ir values should be above 20 Megaohm..

 

[waross]

The old crank type meggers were limited to about 50M Ohms to 100M Ohms by their own internal resistance. New cables on reels is often off scale in the Giga Ohm range.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[alanElec]

Thanks both of you..I meggered all armoured cables and got a value of 1 gigaohm for IR tests(R-Y.Y-R.R-B,R-E,Y-E,B-E,R-N,Y-N.E-N.N-
E)