"Bruce Farquhar" wrote in message
news
I'll just make sure high current devices get polished if the prongs aren't
shiny.

I've done that before now with the plug for a 3-bar (3 kW) electric fire,
when I smelled the plastic of the plug getting a bit hot. The live pin was
actually too hot to touch (*). I removed the plug, took out all the pins
(having dropped the live one in cold water to cool it down!) and used fine
sandpaper on a flat surface to polish the four sides of each pin until they
were shiny.

If I see a high-current device with a removable plug that has oxidised pins,
I remove them and give them the sandpaper treatment. Sadly you can't do that
with moulded-on plugs, and trying to polish them in situ is very hard.


(*) I think the screw that attached the wire to the pin may have been a bit
slack, so there may have been a bit of contact resistance there as well. I
always check that the exposed bit of wire that goes into the screw hole
seems to have about the right thickness of strands and some haven't broken
off - assuming it's stranded rather than solid wire.