Extension lead to computer.

[kol12]

My computer is plugged into a 4 socket surge protected board and then to a extension cord to the
mains socket. The extension cord is pretty old and I've just suddenly wondered if there's any risk in using old extension leads? I have a reasonably new machine so I'm a bit paranoid I guess.

It's quite a long lead and probably unnecessarily long. Reading around it seems the longer the lead is it increases electrical resistance and decreases the power the cord can deliver. Would this affect my machine? Would I better off with a shorter and newer lead?

 

[Karsten75]

Resistance is a function of the quality of the copper that transmits the current, the length and the thickness of the conducting medium (copper). Improve the quality (newer), decrease the distance and increase the thickness to improve the quality of the current delivered.

 

[makkem]

Hi
If you are worried then you should get a new extension cord and 4 way they are pretty cheap.
However if the cord is in good condition with no signs of damage then it should be OK.
The cord is designed to be the correct size for the maximum loading on it and as such will deliver that load without problems.
The only real problems that can occur with extension cords is if they get used at their maximum load while coiled up which can lead to overheating and also that they are prone to physical damage both of which can be avoided somewhat by using the shortest cord you can.

 

[kol12]

So the copper can degrade with age?

 

[Phillip Corcoran]

makkem seems to know what he's talking about - - my dad was an electrician by trade so I learned a lot from him, I can tell you makkem has it spot on.

 

[kol12]

so new extension cords aren't necessarily better or safer than old ones?

 

[makkem]

No the copper does not degrade with age but the insulation can,but you are talking a long time maybe 30 years plus,the main thing to look for is physical damage to the insulation and any discolouration to the insulation caused by heat.
If your extension cord looks to be in good condition then it will be just as good as a new one.

 

[kol12]

Well it's very yellow but that's just the aged white I guess? It's probably about 20 years old.. Will a shorter lead still be more ideal?

 

[kol12]

When I say yellow I mean the whole cord.

 

[makkem]

A shorter lead would be advantageous ,the yellowing is just age and is no problem,heat damage would be brown in a small area.
It is possible to electrically check the insulation and continuity of an extension lead using a high voltage insulation tester if you happen to know an electrician.
I would say that there is no problem with that lead but if you want to get a new one with a shorter cable then go ahead it is less cable to possibly damage or trip over.

 

[tech-wreck]

coiled up extension leads carrying lots of current is a big no-no: i have seen it happen myself, albeit with a 32amp construction cable which wasn't uncoiled, and it melted and shut the transformer off.
make sure it's stretched out and it'll be fine, but if it's a tripping hazard, you could cut it down and re-wire the plug if you're confident.
if it's a uk 3 pin plug, the wires go: earth (yellow /green) (top), neutraL (bLue) (left) and live (bRown) (right)
http://www.frankswebspace.org.uk/ScienceAndMaths/physics/physicsGCSE/wiringPlug.htm