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extension cord on a reel

I have a 50 ft. 3 wire extension cord for use with an electrical leaf blower or weed eater outside. I normally keep the cord wound around a plastic reel whose inside diameter is 6 inches and there are about 50 turns of the cord on the reel when full. A caution on the side of the reel states the "cord should be removed from the reel before use". I assumed that was because of the inductance (and impedance of the 60 Hz current flowing through it) when wound on the reel would impede the current flow in such a coil. Is this truly significant or are there safety factors to be considered? John

Reply to
John Shamblin
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The inductance will be the same, wound or not. They're probably concerned with cooling.

John

Reply to
John Larkin

Another factor could be heat dissipation.

The cable will have some small, but non zero, resistance. This will cause some of the electrical power to be converted to heat in the cable. If the cable is coiled up the heat cannot escape as easily as if the cable were uncoiled. Therefore the temperature rise in the coiled cable will be higher for the same current flow. The coiled cable could therefore overheat and catch fire even though the current was less than the rated current for an uncoiled cable.

Gareth.

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Reply to
Gareth

A buddy of mine had one of these extension cords powering a window air conditioner while coiled up. By the end of the summer the plastic reel had melted to the carpet.

Reply to
Joe

But the issue isn't first that it was rolled up. One doesn't want to use an extension cord without very careful consideration with something that uses power like an air conditioner. And the fact that he had at least some of the cord rolled up means that it was a lousy choice, since he could have used a much shorter extension cord.

Michael

Reply to
Michael Black

blower

reel

of

when

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Overheating- the extension cord is (thermally) rated on the basis that it is
extended and not enclosed. For example, codes would not allow the use of
extension cords in a wall in place of proper wiring. The reel is handy but,
in my mind, its usefulness for storage and winding is outweighed by the fact
that one should completely unwind the cord when using it.
As Rich has said, it's not the inductance.  If your blower is like mine, you
should really have a cord rated at 12A (unwound).
Reply to
Don Kelly

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