poweringtech
Member
What is the rule of thumb to determine if a wire or cable is still in good condition? What should be the minimum acceptable insulation resistance reading to say if the cable is still safe?
Insulation Resistance Test For Wires And Cables
- Thread starter poweringtech
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
An old rule of thumb is one megaohm per thousand volts, but most want to see a much higher reading then that. Also be careful with these types of tests. You can have a damaged conductor, even with bare copper, and pass a megger test if the conduit is dry and the bare copper is not touching a ground path. I have seen cases where the megger showed almost infinite when tested, but as soon as the raceway got wet the circuit failed.
Don
Don
zog
Senior Member
- Location
- Charlotte, NC
What kind of cable are you talking about?
- Status