# What limits the heating power output of a resistor heater?

I'm a bit confused since people said those resistors would draw more power the lower its resistance is, and one way to reduce its resistance is reduce its length.

• Will it draw more power the shorter it is?
• If so, will it stop working past certain point due to temperature being too high?
• If yes, how to find the safe operating range for that heating resistor?

Currently I'm making a heater with "Nikelin" wire as a resistor heater in the form of a coil. I can't find the specification sheet for it anywhere. That "Nikelin" might be called something else in other places. All I know is that it is called that here in Indonesia. I can't even find the manufacturer. Only see it being sold in online and electronic stores.

• I can't read Bahasa Indonesia but this page might be saying that nikelin is the same as nichrome, which is the name for a common heater wire in the English-speaking world. Commented May 10, 2022 at 15:15

Your heater specifications are as shown below.

20 AWG (2mm diameter) Nichrome wire can carry much more than 26.24 A.

15 m of wire would be required per phase to wind an air-heating element.

• Where do you get the 2000 °C and 1000 °C from? Commented May 11, 2022 at 13:44
• @Hearth - Hi! Thank you for your feed back. Had mentioned °C instead of °F. The error has been rectified. Commented May 11, 2022 at 14:00
• It doesn't matter whether it's °C or °F--where do you get the numbers from? I'm not sure how you can compute operating temperature without information on environmental conditions. Commented May 11, 2022 at 14:01
• The numbers are from here. easycalculation.com/engineering/electrical/… Commented May 11, 2022 at 14:04
• @Hearth - I have edited out those numbers. Commented May 11, 2022 at 15:00

will it draw more power the shorter it is?

Yes, assuming your power supply is able to provide enough current.

if so, will it stop working past certain point due to temperature being too high?

The resistor can only get so hot before it burns or melts.

if yes, how to find the safe operating range for that heating resistor?

If nikelin is the same as nichrome wire, you need to keep the temperature below 1400 C (at every point on the wire) to avoid it melting. You could either do that experimentally (heat up some wires and see if they melt), or possibly by monitoring the resistance of the wire (which will depend on temperature).

If you want to reduce the resistance while increasing the power capability, put more resistors in parallel rather than shortening the one you have.

• Of course, you also need to make sure the supports holding the wire are able to handle the temperature as well! Kind of obvious, but possibly easy to overlook. Commented May 10, 2022 at 15:40
• @Hearth, you could just make the supports out of a fatter chunk of nichrome. Commented May 10, 2022 at 15:41
• How do i control that wire assuming i could draw a lot of power from industrial power supply? limiting the current? adding more resistance? using certain tool? (im new to this, i dont even know if such method is possible or such tool exist) Commented May 10, 2022 at 15:41
• @Bramble how much power do you need? Milliwatts? Watts? Kilowatts? Commented May 10, 2022 at 15:42
• its around 10 kilowatts range, i dont know the specified power available, but people i asked says its 3x125A 220V Commented May 10, 2022 at 15:43
1. Don't buy anything without a datasheet unless you know exactly what to expect.