Extension Lead Broken - how to fix/re-wire?

DIYhelp76

Many thanks for the helpful replies. 

It is an old lead but has no visible signs of damage to any of the cable length - we unwound it all and examined. Equally no signs of damage or looseness to either end of the wiring.  All looked sound and tight. 

However, as one person mentioned, it has frequently been used not fully unwound - as it's 25m and we don't need the full length unwound for some of the tasks it is used for.  Is it better then (with any new one) to always unwind it?

Just seemed like a waste to chuck it immediately - we saw an online video where they suggested the approach of trying to cut off a portion of cable at either end to see if that was the problem and checking the reset button.  They did use one of those continuity testing gadgets but we don't have that. Just wanted to try the ends first, to see, as this is a simple task within our capabilities. Just wasn't sure about that crimped part at the end. If this doesn't work then will recycle it as don't have ability or a testing gadget to test/fix the reset button.  Just sorry about the waste, big reel, plastic and metal and such a long length of cable ... hey ho.

Vortigern

DIYhelp76 said:

However, as one person mentioned, it has frequently been used not fully unwound - as it's 25m and we don't need the full length unwound for some of the tasks it is used for.  Is it better then (with any new one) to always unwind it?

Yes, it should always be fully unwound, except for very short duration low power jobs, like drilling a hole in wood. If you use it coiled up for a few minutes the coiled cable will get hot and trip the thermal cutout. Can you reset or replace the thermal cutout? Sometimes you have to press hard on the button to get it to stay down.

Vortigern

@DIYhelp76 If you Google "thermal cutout button" you'll see one that looks very much like yours.

Ectophile

You'll know if the failure was down to the lead being used coiled up - all the plastic will be melted.

Leads should be fully unwound when powering high power appliances.  It's not so important for low power ones.

Vortigern

Ectophile said:

You'll know if the failure was down to the lead being used coiled up - all the plastic will be melted.

Not if the thermal cutout does its job. I would be testing the cutout for continuity. Prime suspect here IMHO.

HKrepat

If the extension lead suddenly stopped working - then most likely it is the thermal cutout, as above, or the fuse.

But if the extension lead is one that worked last month, last year, or earlier, it could be contact issues either with the plug, or with the sockets in the hub. I spent about an hour dismantling a similar but older model - without thermal cutout - and the problem was simply an insulating patina on the mains plug.

Once I had identified the problem with a multimeter, I simply sprayed switch contact cleaner into each of the four earth, four neutral and four live contacts, tightened each of them a bit with a flat bladed screwdriver, so that they would each better grip incoming plugs, and plugged the mains plug into each in turn to test their grip and to clean the plug's contacts.

Tested with a Henry vacuum cleaner, which has a reassuringly large red neon mains indicator light.

Of the hour or so I actually spent, I could have saved 55 minutes by just changing the fuse - which I had one first of all - and then using the contact cleaner!

Please note - highly recommended to plug the extension lead into an RCD protected socket! Older outdoor sockets are most likely not protected, so this will necessitate a separate plug-in RCD unit.