# wire wound resistor

#### matty204359

Joined Apr 6, 2011
105
Does any body have an idea what kind of wattage this resistor can take? the wire appears to be about 16 gauge(the wire has a diameter of 1.01 mm according to my dial vernier) and has a resistance of 11 ohms. I don't know the length of the wire.

#### tracecom

Joined Apr 16, 2010
3,944
Just guessing based on the physical size, I would say 100 watts or more. You can count the turns and measure the diameter to get a close idea of the total wire length. Then, you could use that with the total resistance to know the resistance per inch, and then correlate that to what the composition of the wire is, and then get a better idea of its rating.

What does the wire seem to be made of? Could it be nichrome? I wonder if it was built to use as a heating element.

#### mik3

Joined Feb 4, 2008
4,843
I would say 500W for sure!

#### cork_ie

Joined Oct 8, 2011
428
Looks like a cut down element from an electric heater.
These normally glowed bright red . They were about 14" long and 1KW.

while it would probably tolerate 500W
I would say c. 100W is more like the intended limit

#### matty204359

Joined Apr 6, 2011
105
excellent, it will be a good dummy/test load! I don't know how to tell if its nichrome wire. I measured the diameter and it ranges from 1 3/8" - 1 7/16" because its not perfectly cylindrical. it has 61 turns with a circumference of 4 1/3" - 4 1/2". giving me a wire length of 264 1/3"(33.9 milliohms per an inch). - 275 1/2"(39.9 milliohms per an inch). Does anybody know what nichrome's resistance per an inch or foot is?

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#### matty204359

Joined Apr 6, 2011
105
sorry 18 gauge is the wire thinckness. I've tried google, I'm not having luck determining the resistance per foot/inch of 18 gauge nichrome wire.

#### tracecom

Joined Apr 16, 2010
3,944
18 awg nichrome is .422 ohms per foot, which translates to .035 ohms per inch.

#### matty204359

Joined Apr 6, 2011
105
18 awg nichrome is .422 ohms per foot, which translates to .035 ohms per inch.
that fits great with my estimated 33.9 -39.9 milliohms of resistance per an inch.

#### tracecom

Joined Apr 16, 2010
3,944
that fits great with my estimated wire length and estimated 33.9 -39.9 milliohms of resistance per an inch.
So, it is quite likely 18 awg nichrome. I agree with cork_ie that it is part of a heating element that has been cut down for some special purpose - maybe a dummy load for something, or maybe a heating element for some specific voltage. Ohms law will tell you how much current it will conduct at various voltages.

#### #12

Joined Nov 30, 2010
18,223
You've probably realized that nichrome comes in different diameters for different purposes. In my clothes dryer, there are 2 diameters, one for 1800 watts and one for 5000 watts. I'm sure there are several more sizes.