I think many of the moulded plugs are hard to plug-in and un-plug, and often don't get much better over time. Probably as years go by and the insulation ages with repeated use eventually the wire itself is carrying tension/compression loads and strands break=less copper to bump those electrons along and heat results. Maybe not so much or as soon with the heavier gauge wire?
Some Extension Cord Testing
- Thread starter jstutz
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Originally Posted By: jstutz
Aftermarket ends ( good ones ) hold up much better and longer than the cheap factory ones and most likely better then the good factory ones.
4) All factory ends that got hot and were replaced with good ends, did not get hot anymore, and of all the cords i tested that had aftermarket ends on them, none got hot. This is convincing enough for me to pretty much use aftermarket ends on all but the lightest duty cords that i know will just be for a light or something.
Bingo. Quality ends are definitely worth the money. 22yrs ago I made up a 30' cord using 12/3 wire. I bought two industrial grade 20A outlets and put them in a metal duplex box. Tinned the wire ends and screwed them down firmly. These hold the plug so tight I have to hold the box down with my foot and then give a firm tug to the plug to extract it. These tight wipers remove any corrosion when the plug is inserted.
I did the same thing to the 8' ceiling outlet in the garage where the door opener plugs into. Replaced it with a duplex box and the same quality outlets. Sure is nice having 3 quality outlets easily within reach when working in the garage without having to drag out an extension cord.
There's a HUGE difference between standard, commercial, industrial, & hospital grade outlets. The first are just worthless and that's what's on the end of most cords you buy. As soon as any corrosion sets in, up goes the contact resistance. Put enough watts through that and now you're generating heat, P=i^2R.
This being a square law eqn. the heat generated quickly goes up the more current you put through it. The difference between 5A and 10A isn't just a doubling of the current, it's a 300% increase in power delivered.
Aftermarket ends ( good ones ) hold up much better and longer than the cheap factory ones and most likely better then the good factory ones.
4) All factory ends that got hot and were replaced with good ends, did not get hot anymore, and of all the cords i tested that had aftermarket ends on them, none got hot. This is convincing enough for me to pretty much use aftermarket ends on all but the lightest duty cords that i know will just be for a light or something.
Bingo. Quality ends are definitely worth the money. 22yrs ago I made up a 30' cord using 12/3 wire. I bought two industrial grade 20A outlets and put them in a metal duplex box. Tinned the wire ends and screwed them down firmly. These hold the plug so tight I have to hold the box down with my foot and then give a firm tug to the plug to extract it. These tight wipers remove any corrosion when the plug is inserted.
I did the same thing to the 8' ceiling outlet in the garage where the door opener plugs into. Replaced it with a duplex box and the same quality outlets. Sure is nice having 3 quality outlets easily within reach when working in the garage without having to drag out an extension cord.
There's a HUGE difference between standard, commercial, industrial, & hospital grade outlets. The first are just worthless and that's what's on the end of most cords you buy. As soon as any corrosion sets in, up goes the contact resistance. Put enough watts through that and now you're generating heat, P=i^2R.
This being a square law eqn. the heat generated quickly goes up the more current you put through it. The difference between 5A and 10A isn't just a doubling of the current, it's a 300% increase in power delivered.
An interesting read about 50ft 12/3 extension cords:
https://thewirecutter.com/reviews/best-extension-cords-for-your-home-and-garage/
A useful chart showing ampacity of extension cords, for lengths less than 50ft and over 50ft.
https://www.stayonline.com/reference-circuit-ampacity.aspx
https://thewirecutter.com/reviews/best-extension-cords-for-your-home-and-garage/
A useful chart showing ampacity of extension cords, for lengths less than 50ft and over 50ft.
https://www.stayonline.com/reference-circuit-ampacity.aspx
The resistance of the cord and connections are also causing a voltage drop which just causes resistive loads like heaters, and lights to have less output. But, on inductive loads, like motors on power saws, compressors, etc., the voltage drop will cause the current to go even higher with the motor running slower, and overheating, tripping breakers. Also, as the cord gets warmer, that causes the resistance to rise too. The heat in the cord is wasted energy that is not providing power to the device. It all comes down to OHM's law.
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This is a great thread. I spend way too much time explaining to people that they need to spend real money on decent extension cords for things to work properly.
Two examples...
I maintain all of the generators and UPS power for Time Warner corporate and CNN studios in NYC. People in the building call me for all electrical issues. Once, the CNN stage hands called and said a whole bunch of equipment in the big studio either would not operate properly or was tripping breakers, can't remember. Anyway, I go down there and find extension cords plugged into extension cords and power strips with more extension cords. They just kept plugging in more cords and strips. I instructed them to get rid of any cord with 14 ga wire and we limited all cord length to 50 feet. We eliminated hundreds of feet of cord and a box of power strips. I don't think they've called me again with this problem in six years.
Another time, this woman with TW was hosting a food drive to bring Thanksgiving dinner to poor people. They were vacuum packing food and heat sealing the packages. They were going to have something like 25 stations set up and wanted us (Engineering) to supply extension cords and power strips. I told her we didn't have enough cords in the building and NO WAY on power strips. She became very nasty and didn't want to listen when I told her what was required to do this properly. Finally, later in the day, some different person from her department asked me what we needed and ordered twelve hundred dollars worth of heavy duty extension cords. The food drive went off without a hitch, not even a tripped breaker. Never got a thank you or a you were right or anything.
Two examples...
I maintain all of the generators and UPS power for Time Warner corporate and CNN studios in NYC. People in the building call me for all electrical issues. Once, the CNN stage hands called and said a whole bunch of equipment in the big studio either would not operate properly or was tripping breakers, can't remember. Anyway, I go down there and find extension cords plugged into extension cords and power strips with more extension cords. They just kept plugging in more cords and strips. I instructed them to get rid of any cord with 14 ga wire and we limited all cord length to 50 feet. We eliminated hundreds of feet of cord and a box of power strips. I don't think they've called me again with this problem in six years.
Another time, this woman with TW was hosting a food drive to bring Thanksgiving dinner to poor people. They were vacuum packing food and heat sealing the packages. They were going to have something like 25 stations set up and wanted us (Engineering) to supply extension cords and power strips. I told her we didn't have enough cords in the building and NO WAY on power strips. She became very nasty and didn't want to listen when I told her what was required to do this properly. Finally, later in the day, some different person from her department asked me what we needed and ordered twelve hundred dollars worth of heavy duty extension cords. The food drive went off without a hitch, not even a tripped breaker. Never got a thank you or a you were right or anything.
Originally Posted By: sleddriver
...I bought two industrial grade 20A outlets and put them in a metal duplex box. Tinned the wire ends and screwed them down firmly...
I just bought a Leviton 20A/125V angle plug. On the instruction sheet is the warning "Caution: Do NOT tin the conductors".
...I bought two industrial grade 20A outlets and put them in a metal duplex box. Tinned the wire ends and screwed them down firmly...
I just bought a Leviton 20A/125V angle plug. On the instruction sheet is the warning "Caution: Do NOT tin the conductors".
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