Caravan Electric Hook Up Cable

[bigbanana]

My neighbour took his touring caravan back to the campsite yesterday where it will spend the whole season. He took out the electric hook up cable (ehu) from the locker and connected one end of the electric supply on the post at the rear of the caravan and the other to the caravan connector. The post end is a blue/white 16a industrial male plug and the other end is a female version.
On switching on the power, no 240v mains was available. Fuses, mcb's were checked and the cable was taken to another post and plugged in to see if that was a problem. Eventually the ehu connectors were dismantled. The caravan end was OK. But in the one that plugs into the supply post, the neutral copper core was the colour of Ash right into the terminal and turned to powder on touching with a screwdriver tip. The neutral core blue insulation had melted and was distorted. There was no sign or smell of burning although the blue insulation looked like it had melted.
Has anyone any suggestions about why this happened? There were no problems withe the ehu when it was put away last year. The ehu worked fine when the damaged section was cut out and the connections remade.
Thank you.

[bhg481]

It sounds like corrosion, although I've never had it happen to me and my cable is 20 years old.

[The Builder]

Most likely arcing caused by loose connection(s).
16A (or any current really) can produce a substantial arc if the cable is wobbling around making an "on-off" connection.

Check them every season maybe ;o)

[bhg481]

That seems a more likely cause than corrosion - it explains the melted blue insulation and could have been caused by moving the cable in the car if the connector hadn't been tightened properly in the first place.

[bigbanana]

Thank you both for your advice. I think I'll advise him take the cover off the plug and socket at the beginning of the season every year to check the connections from now on as you suggest.

[richtee]

Loose connection as said, with little doubt.