I'm hoping someone can answer a questions about the best way to connect two extension cords. Both are 50' long. One is made of 14/3 wires. The other is made with 12/3 wires. My question is which one should be connected closest to the wall plug? The heavier gauge cord or should that be the one on the end of the connection as it would have less resistence?
Any comments and recommendations would be appreciated.
Thanks, Frank
It doesn't matter. The total resistance is the same, regardless of which way you connect them.
(At the risk of starting another "run or walk through rain" controversy:)
Series AC impedance (unlike DC resistance) is minimized by ordering the segment impedance to increase towards the load. So put the 14/3 after the
12/3 if you want to be perfect about it. But the AC impedance effect is trivial in this situation, so it doesn't really matter.
Actually, that one *does* make a noticeable difference, unlike the extension cords.
Then why did you mention it?
Unless the device you need to power draws very little power and doesn't care about voltage, you really should get a proper 10/3 100 foot extension cord. Just the 50 foot 14/3 is going to have significant losses from end to end. Generally speaking, in home wiring, you don't want to run more than 50 feet from the service entrance with 14 gauge wire because of the voltage drop encountered. That means that a 14/3 extension cord is the minimum size for a 50 foot run if you plug it in AT the service entrance. If the power is already running through wiring to the outlet, then you really need the big expensive extension cord that you are hoping to avoid. Even a single 100 foot 12/3 cord would be somewhat preferable to the two cords you have now. You can get a 100 foot 10/3 extension at the big box stores for around $100. A 12/3 for about $50.
Put the 12 guage first, then the 14. But the only reason is because it will be easier to move around with the lighter cord on the end. Electrically it is the same.
Bob
I was going to say "wire nuts" but he probably wants to use the cords again. I like your logic, to put the lighter cord out where it's moving around.
Electrically, it's all the same. They are in series.
Ummmmm.... 14ga copper wire has a resistance of 2.58 milliohms per foot, or
129 milliohms in fifty feet. Just how much of a loss do you suppose that's going to cause?
Enough. Go measure if you are not sure.
CWM
Ummmm.. no. Plugging one into the other constitutes a junction point, nothing more.
That's 258 milliohms per 50 feet (there's two conductors) It's enough to sometimes cause a 1.5 HP capacitor-start motor to fail to start. BTDT. It's probably not significant for anything else.
Bob
Lordy. Go to Sams Club or wherever, spend 30 or 40 bucks, and get a proper
100-foot contractor cord. That is what I did when I noticed the connectors on the strung-together cords I was using were getting rather warm to the touch. It is heavy, so it is a workout rolling it up and carrying it, but all the connections stay nice and cool now. Plus, the GFCI doesn't trip any more.aem sends....
No difference, from theoretical electrical viewpoint. And assuming the voltage is nominal 115 volts. What are the 12/3 or 14/3 extension cords to be used to power? If it's a single 60 watt inspection lamp bulb, volt drop insignificant. To try and power a 3 HP compressor or something which has an ampere load exceeding the rated ampacity of #14 AWG, possibly major volt drop problems especially during motor starts.
Thanks for the quick replies. I appreciate the information. This is for a fence repair project so I'll be using the cords to power a battery charger (drill and screw driver) and a portable circular saw (about 13 amps) for short periods of time (long enough to cut 4" x
3/4" cedar boards to length).
Is it a 15a or 20a circuit? How far is the outlet from the breaker box? I wouldn't run a 13a saw on it unless it was a 20a circuit close to the breaker box. Charger should be fine...
Depends on how much an energy hog the equipment is. Putting a 14/3 25' extensions cord on a small air compressor can cause blown breakers where no extension cord causes no problem. For a normal 3/8" drill you would probably not notice much of a difference at 100' if you were not working at the limit of the drill.
You might get by with it. If you measure what you need and cut the boards at the house you will have no problem at all and you will have less weight to carry all the way back to the fence.
Circular saws have universal motors. They handle low voltage much better than induction motors. Should be fine. If he uses it continuously, the connections may get hot, but nobody uses a portable saw that way.
Why wouldn't you run a 13A load on a 15A circuit (assuming the circuit wasn't already heavily loaded)?
Bob
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.