Extension cord problem. Electrical gurus, pipe in please.

[Jonhilgen]

I have a 25' 12 gauge cord with "aftermarket" ends on the cords.  After being used and abused, the ends that came with the cord needed to be replaced.

This Friday, I was cutting through some 4 1/2" maple island legs, and halfway through, the gfi I had plugged into had popped.  So I went over to pilull the plug and push the reset.  When I pulled the plug, I had inadvertently touched the prongs and actually burnt my hand.

Can these aftermarket ends be the issue?  I have them crimped on the cord pretty tight.  Is this causing some restriction?  I've noticed this Ina much smaller scale when I have this plugged into a work light (will never use this cord for that again.)

Any insight would be helpful.

Thanks guys.

Jon

 

[Sparktrician]

I have a 25' 12 gauge cord with "aftermarket" ends on the cords.  After being used and abused, the ends that came with the cord needed to be replaced.

This Friday, I was cutting through some 4 1/2" maple island legs, and halfway through, the gfi I had plugged into had popped.  So I went over to pilull the plug and push the reset.  When I pulled the plug, I had inadvertently touched the prongs and actually burnt my hand.

Can these aftermarket ends be the issue?  I have them crimped on the cord pretty tight.  Is this causing some restriction?  I've noticed this Ina much smaller scale when I have this plugged into a work light (will never use this cord for that again.)

Any insight would be helpful.

Thanks guys.

Jon

Yes, the ends CAN be the issue.  Get some decent replacement end connectors and replace the current ones.  If they're getting hot, it means that there is too much resistance to current flow.  The cause may be worn metal parts inside the current connectors or oxidation of the metal parts.  It's best to strip the ends and pre-conform them to the screw terminals of the connectors, then tin them lightly with a soldering iron before attaching the connectors.  If you need some in-fill on this, ping me via PM with your phone number and I'll talk you through it. 

 

[Jonhilgen]

Here's  some pics of the ends.  Looks like the female end is definitely crimping the wires too much?  I did this thinking it was better to have it a little tight instead of the sleeve eventually sliding out of the end...need to rework this STAT.

Think this is the case Willy?

Thanks.

 

[Sparktrician]

Yes, that CAN be an issue with the wire inside the insulation being crimped to the point of separation inside the insulation.  Over-clamping is as much of a problem as under-clamping. 

 

[woodie]

Yes, the ends CAN be the issue.  Get some decent replacement end connectors and replace the current ones.  If they're getting hot, it means that there is too much resistance to current flow.  The cause may be worn metal parts inside the current connectors or oxidation of the metal parts.  It's best to strip the ends and pre-conform them to the screw terminals of the connectors, then tin them lightly with a soldering iron before attaching the connectors.  If you need some in-fill on this, ping me via PM with your phone number and I'll talk you through it. 

Not to go against a guy with a username like Spartrician, as I'm sure you know far more than I do regarding electricity.  That said, tinning leads that go to any kind of screw terminal is a bad idea. I work in the A/V world and I can't tell you how many times I've seen low voltage connections fail because of this. Just google "solder creep + screw terminal".  Here's the first one I found.

https://groups.google.com/forum/m/#!topic/uk.d-i-y/5CeMxMZQZbk

 

[woodie]

I would definitely cut your cable back beyond where the strain relief is now and remake your cable.  As already mentioned, don't tighten the strain relief quite so much. Do make sure to tighten the screws on the wire as tight as possible.

 

[jonny round boy]

Yes, the ends CAN be the issue.  Get some decent replacement end connectors and replace the current ones.  If they're getting hot, it means that there is too much resistance to current flow.  The cause may be worn metal parts inside the current connectors or oxidation of the metal parts.  It's best to strip the ends and pre-conform them to the screw terminals of the connectors, then tin them lightly with a soldering iron before attaching the connectors.  If you need some in-fill on this, ping me via PM with your phone number and I'll talk you through it. 

Not to go against a guy with a username like Spartrician, as I'm sure you know far more than I do regarding electricity.  That said, tinning leads that go to any kind of screw terminal is a bad idea. I work in the A/V world and I can't tell you how many times I've seen low voltage connections fail because of this. Just google "solder creep + screw terminal".  Here's the first one I found.

https://groups.google.com/forum/m/#!topic/uk.d-i-y/5CeMxMZQZbk

I agree with that. When I worked for a company making bespoke wiring/pcb assemblies for specialist vehicles, I was taught that you should never tin wires that were going into a screw terminal. It will always cause problems in time.

 

[Rick Christopherson]

Here's  some pics of the ends.  Looks like the female end is definitely crimping the wires too much?  

Jon, the aspect you are referring to in your pictures is just the cord grip, and this is not impacting the electrical aspects of the cord. As a matter of fact, those are good quality cord caps on the end of your cord, and will provide a much improved function of the cord compared to the original molded ends.

However, what you should do is open up those cord caps and verify that the lugs on the screw terminals are still tight against the copper. If they are loose, they can be a source of heating of the ends.

 

[Jonhilgen]

Here's  some pics of the ends.  Looks like the female end is definitely crimping the wires too much?  

Jon, the aspect you are referring to in your pictures is just the cord grip, and this is not impacting the electrical aspects of the cord. As a matter of fact, those are good quality cord caps on the end of your cord, and will provide a much improved function of the cord compared to the original molded ends.

However, what you should do is open up those cord caps and verify that the lugs on the screw terminals are still tight against the copper. If they are loose, they can be a source of heating of the ends.

This is the perfect case of asking a question without looking into something first...Rick nailed it, on both ends the hot/black wire had come loose.  I'm not sure how, I know I tightened them well.  I think that I didn't expose enough of the wire  could be secured by the lugs.  I've reworked both ends, and will test them out with my work light tomorrow.

Thanks guys!

 

[Rick Christopherson]

Jon, it is hard to tell from the pictures, but those appear to be clamping-type lugs. In other words, the wire is sandwiched between two metal plates and not against the head of the screw. When putting the wire back in, make sure to loosen the screw almost all the way and jiggle it if necessary to separate the two plates.

It kind of looks like you had the wire originally installed under the screw head instead of between the plates.

Also, I would recut the wire to remove the original exposed copper. It appears to be slightly corroded.

When stripping the wire, you can strip a little bit more than what you have. One of the most common mistakes when installing wire like this is to have too short of exposed wire and having some of the insulation under the clamp instead of just bare copper.

Oh P.S. you had the strain relief properly tightened in the original pictures. Don't leave them loose. Fully tighten those exterior screws.

 

[semenza]

I have used those exact plug ends. They are a clamping type lug.

Seth

 

[Guilliaume woodworks]

Where the cord enters the plug there are the two black half circle grommet looking  things. Slide them out of housing and flip them over. The black half circle things, have larger strain relief inlet hole on opposite side. Take a look , I'm almost positive it's the same plug ends I've bought for years.

 

[Guilliaume woodworks]

Pics of what I'm talkin about