Winding cords?
- Thread starter mrmcfly
- Start date
Renfro
Well-Known Member
It's not a problem.
DCcan
Well-Known Member
It's a problem if you make induction coils, nice and tightly wound.
They produce heat and voltage loss.
Like light cords with 30 wraps instead of 4-5 loops.
That extension cord was probably losing 40vAC to induction while running a string of Christmas lights, then melted.
The one below it was tightly clamped and wound, also producing a hot spot.
They produce heat and voltage loss.
Like light cords with 30 wraps instead of 4-5 loops.
That extension cord was probably losing 40vAC to induction while running a string of Christmas lights, then melted.
The one below it was tightly clamped and wound, also producing a hot spot.
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Renfro
Well-Known Member
Well the fact you have both conductors means the current is flowing in both directions in the coil and therefore they cancel each other out.It's a problem if you make induction coils, nice and tightly wound.
They produce heat and voltage loss.
Like light cords with 30 wraps instead of 4-5 loops.
That extension cord was probably losing 40vAC to induction while running a string of Christmas lights, then melted.
The one below it was tightly clamped and wound, also producing a hot spot.
View attachment 4674652
Renfro
Well-Known Member
An extension cord that is in use while coiled up or coiled in a reel can be a serious shock and fire hazard. The heat produced from the resistance cannot dissipate and is instead trapped between the tightly coiled cable, leading to the a fire or shock.
The magnetic fields of the two current carrying conductors (going in opposite directions) do cancel each other out, but you can think what you like.
The magnetic fields of the two current carrying conductors (going in opposite directions) do cancel each other out, but you can think what you like.
DCcan
Well-Known Member
Its been done already. 60 hz just means it heats up and then goes to zero and heats up again, instead of continuously.
It also creates an induction field every cycle, which draws current and drops the output voltage...a cord like this cant put 75 volts at the output.
Exhibit A:
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mrmcfly
Active Member
Here is a picture of what I'm talking about. I wrapped them back n forth, not like a coil. I might just be overthinking things but I remembered something about it creating extra heat/ issues and couldn't find an answer whether it might damage equipment. I think I might just turn them on for a while and keep an eye on temperature. Thanks for input.
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stalebiscuit
Well-Known Member
that seems fine imo
Renfro
Well-Known Member
The electromagnetic fields generated from the current flowing in opposite directions parallel to each other do cancel each other out, it is for this exact reason that you can't use an inductive amp clamp on an extension cable without opening it and isolating one or the other current carrying conductors into the clamp probe.
Your melted cable is common with a lack of heat dissipation on a heavily loaded extension cord, the heat created from I2R is trapped in the coils. It is common that such coiled extension cables only be loaded to half their rated ampacity in order to avoid excessive heat in the coil.
devilboy13
Member
No don’t wind them tight. Loosely drape them or they will overheat and melt and start on fire.
MICHI-CAN
Well-Known Member
Not quite sure why we are discussing electro magnetics and induction? The concern here is resistance and thermal dynamics. A high load "Amps" on a small dia "AWG" will generate more heat than a larger gauge. But you must consider length when figuring resistance as well. This coupled with close proximity of closely coiled cord increase insulation value and thermal generation as well. In my language you can coil if the the rating or AWG is twice the minimun rating for your load and length. Best bet is large loose loops exposed to airflow. Be safe. We grow fire. Not start them.
xox
Well-Known Member
i agree with this statement i've used an extension cord like that on a job overloaded the circuit with to many power tools plugged into that exact type in the photo and it melted how it is in that photo. is that photo just something that was pulled off google?
MICHI-CAN
Well-Known Member
Magnets generate negligible heat at best. I don't get the relationship with heat melting things beyond drawing coils closer together to increase thermal insulating which is impossible because we use non fer-rites for conductors over distance.
I hope the OP followed my advice. You kinda backed it up.
xox
Well-Known Member
everytime ive used an extension cord on a spool they never have a splitter on them that has a gfi built into the outlet they often melt when too many tools are plugged into them. here let me help you https://bfy.tw/P7Db
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