How to find out whether the pvc insulation of wires is of good quality or bad?

Question

if any expert pls tell me how to find out what kind of pvc is used in the wire

Answer 1

Get a short length of the PVC insulated wire. Place in a pan and heat up. Check with a glass thermometer the temperature the wire starts to melt or burn.Check if the wire doesn't melt or burn as seen on its printed temperature limits.

Answer 2

Using an Insulation Resistance tester "Megger" will indicate if pvc insulation is good or bad.Connect one lead to cable wire and other to ground or earth connection

A Polarization Index test is performed.Take a reading after one minute and another reading after ten minutes.

Polarized Index = I0 min reading/1 min reading.

A PI reading of between 1.5 to 3 would be considered OK.

The higher the PI reading the insulation is considered too dry, brittle i.e 5 to 10

Lower than 1 is considered to moist.

Hope this will help you doing some further research.