Reverse Polarity

[TBOT422]

We need a couple of new 30A shore power cables. I was able to pick up a used one at an auction. It appears to be in good condition with no dark 'sparking' areas at either of the connections. When I connected it to shore power, the reverse polarity light came on and nothing worked. I disconnected it and ran a different cable through the same shore power outlet and all was fine, so the problem seems to be with the cable itself.

My question is - Is this something that can be repaired on the cable or is it desitned for the scrap heap, or sold to a recycler for the copper content? Can the issue be verified via continuity testing on the cable, or some other means?

Thanks

[wolfe10]

Gary,

Pull out your ohm meter. And, with the ends unplugged, compare male prong to female slot location of hot/neutral/ground between the known good and the one that shows reverse polarity.

Also, check for direct contact/short/low ohm reading between prongs-- there should be none (no contact between hot, neutral and ground prongs).

It may be that you can salvage the bad cord by either connecting the wires correctly or replacing the errant end.

[KenKrawford]

Gary are the plugs on both ends factory originals? If so and there is no sign of burning/arcing then the problem almost certainly has to be with the insulation on the 3 cable strands. Run the checks that Brett suggested and let us know what you find.
If the cord is a name brand (Marinco, Hubbel) it also might be worth giving the manufacturer a call and see what they say.

[D&M]

This can sometimes be erroneous. I have seen it several times at pedestals in my marina (240v Australia). Sounds silly but plug it in to another shore pedestal, before blaming the cable.