If you have a 240V circuit underground in PVC and every time it rains you are having a issue with the breaker tripping, should I megger the wires when it is not raining, or when it is raining? Can a megger detect damage on the insulation of a single wire, even if it is dry and not leaking any current? Don't have much experience using them. Thank you for your help.
Meggering question
- Thread starter zappy
- Start date
- Status
ptonsparky
Tom
- Occupation
- EC - retired
You will be more comfortable if it is not raining. The megger will work either way. Check wire to wire as well as to ground.
brian john
Senior Member
- Location
- Leesburg, VA
A conductor with damage insulation in PVC can be the one tough item to catch with a megger. I would shoot for when it trips and in your case that is when it rains.
Though unless the conduit is arranged to drain (damaged) it seems the water should be present most of the time.
Though unless the conduit is arranged to drain (damaged) it seems the water should be present most of the time.
ptonsparky
Tom
- Occupation
- EC - retired
If you know the problem is in a wet conduit, replace the wires. A megger is only going to confirm it, and the wires will still need to be replaced.
On long buried runs we can usually find the problem with a fault finder. The pvc is generally cracked in the immediat area of the fault.
On long buried runs we can usually find the problem with a fault finder. The pvc is generally cracked in the immediat area of the fault.
- Status