Why aren't the coils in electric motors insulated?

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Discussion Overview

The discussion revolves around the insulation of coils in electric motors, specifically addressing whether the coils are insulated and the implications of insulation on magnetic field generation. Participants explore the types of coatings on magnet wire and methods for removing insulation, touching on both practical and theoretical aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related
  • Experimental/applied

Main Points Raised

  • Some participants assert that the coils in electric motors are insulated with a thin layer of enamel, while others question the visibility and nature of this insulation.
  • There is a suggestion that magnet wire may appear similar to bare copper due to its coating, which is often gold or other colors.
  • Participants discuss various methods for removing the insulation from magnet wire, including using flame, scratching with a knife, and wire strippers, with differing opinions on their effectiveness.
  • One participant mentions that modern enamelled wire has a plastic coating that burns off during soldering, contrasting with older types that require scraping.
  • Anecdotal methods for stripping enamel insulation, such as using an aspirin tablet, are mentioned but not confirmed as effective.

Areas of Agreement / Disagreement

There is no consensus on the visibility or nature of the insulation on magnet wire, as some participants believe it is transparent while others disagree. Additionally, there are multiple views on the best methods for removing insulation, indicating a lack of agreement on this practical aspect.

Contextual Notes

The discussion includes various assumptions about the types of insulation and their properties, as well as the effectiveness of different removal techniques, which may depend on specific wire types and user experience.

Who May Find This Useful

This discussion may be useful for hobbyists, engineers, and students interested in electric motor construction, repair, or the properties of magnet wire and insulation techniques.

Xyius
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In all the electric motors I have taken apart, the coils on the armature have never been insulated. This has always confused me because, how could the coil make a sufficient magnetic field if it shorts out to the adjacent wires from lack of insulation?
 
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Are you sure they're not coated in a thin layer of clear sheathing?
 
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DaveC426913 said:
Are you sure they're not coated in a thin layer of clear sheathing?

I have suspected that but I do not know for sure. I was wondering if anyone else could confirm. :]
 
They are insulated with a thin transparent layer of insulator.
 
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Hassan2 said:
They are insulated with a think transparent layer of insulator.

No, I don't think it's transparent.

Magnet wire is coated with a thin layer of enamel. The color is usually gold, making it appear similar to bare copper. It also comes in other colors, such as red and green.
 
Cool thanks guys!
 
TurtleMeister said:
No, I don't think it's transparent.

Magnet wire is coated with a thin layer of enamel. The color is usually gold, making it appear similar to bare copper. It also comes in other colors, such as red and green.

Thanks a lot. Do you know how to remove the insulation before soldering? Or is it removed by the heat while soldering? I usually use flame to remove the insulation first. Sometimes just scratching them by a knife! I wonder if there was a more efficient way.
 
Hassan2 said:
Thanks a lot. Do you know how to remove the insulation before soldering? Or is it removed by the heat while soldering? I usually use flame to remove the insulation first. Sometimes just scratching them by a knife! I wonder if there was a more efficient way.

Wire strippers are the correct way.
 
Hassan2 said:
Thanks a lot. Do you know how to remove the insulation before soldering? Or is it removed by the heat while soldering? I usually use flame to remove the insulation first. Sometimes just scratching them by a knife! I wonder if there was a more efficient way.

Yes, there is a more efficient way. You can buy a machine that is designed for removing the insulation. However, the price is probably too high for the hobbyest. I used such a machine many years ago when I worked for a motor manufacturer. At home I usually just lay it on a flat hard surface and scrape it with a sharp knife. I've never had much luck with using wire strippers on magnet wire.
 
  • #10
DaveC426913 said:
Wire strippers are the correct way.

How do you use wire strippers to take off such a thing layer?
 
  • #11
Pengwuino said:
How do you use wire strippers to take off such a thing layer?

Mm. Good point. It's not designed to be stripped like regular electrical wire, is it? It won't just slide off.
 
  • #12
Modern "enamelled" wire usually has a plastic coating that will burn off cleanly during soldering. The wire in old motors etc uses "real" enamel which needs to be scraped off with a knife blade or fine sandpaper.

There are electrically powered tools available to do this on an "industrial" scale.
 
  • #13
Apparently some types of enamel could be stripped by placing the wire on aspirin tablet and heating with a soldering iron (or so the urban legend says). Never tried it myself though.
 
  • #14
Use a pocket knife and scrap off the ends like you would to strip off plastic insulation.
 

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