Joel Fox

Here is a link to Biddle's information page.

http://www.metercenter.com/cgi-bin/webshop.cgi?config=en-app

For megga the insulation of the wire, the "Red lead" (live) is clamp to the cable copper wire and the "Black lead" (earth) is clamp to the earth or clamp to the armoured of the cable if you are using the armoured cable which is earthed.

Select the proper insulation voltage level. 250V for cable that carry 220 Vac, 500V for cable carry 415Vac and 1000V for Cable carry 660Vac.

During the cable insulation test, if the megga indicate the higher value, it show that the cable insulation is very good. Cable with insulation level of less than 5M Ohm is consider low insulation but still can be used with out any problem.

Insulation level less than 1M Ohm is consider very low insulation.

whilst referring to typical/expected megger values - remember that megger value for any insulation depends on various factors -

1. insulation material - pvc/rubber/xlpe/paper/teflon/etc - hygroscopicity, porosity, density

2. thickness and length / surface area (generally geometry) of layer

3. relative humidity of atmosphere at the time of measurement - ambient temperature

the pass or fail criteria and suitable pass value depends on the application / use and the above conditions together and is generally agreed by the purchaser and seller in consultation with local electrical and safety rules in force.