Use different size wire in electro clutch?

[DaveC]

The coil in an industrial electromagnetic clutch (connecting the flywheel to
the drive mechanism) has gone open-circuit. So it is being rewound by a motor
rewind shop.

I was just informed that the original wire was about 12 ga. (maybe slightly
larger; original was metric) but it was rewound using 10 ga.

Should I be worried about this change in wire size? Will this change the
magnet's strength significantly? The current draw?

Here's the original schematic:

<http://i47.tinypic.com/2lkpt94.jpg>

"F" is the clutch coil. The machine isn't currently wired to mains so the
clutch's exact operating voltage isn't known. The transformer voltage that
supplies the rectifier bridge seems to be 32 v (per label on the schematic).
Here's photos of the clutch. (The coil is imbedded in a groove in the metal
cylinder.) ::

<http://i48.tinypic.com/2hnyqll.jpg>

<http://i46.tinypic.com/2nlg5de.jpg>

<http://i49.tinypic.com/24pjaqu.jpg>

<http://i45.tinypic.com/29bdduw.jpg>

<http://i47.tinypic.com/291c7cw.jpg>

Will this change in wire size cause me troubles?

Thanks,
Dave

 

[Eeyore]

The coil in an industrial electromagnetic clutch (connecting the flywheel to
the drive mechanism) has gone open-circuit. So it is being rewound by a motor
rewind shop.

I was just informed that the original wire was about 12 ga. (maybe slightly
larger; original was metric) but it was rewound using 10 ga.

Why do Americans persist in using stupid AWG that no-one else in the
world uses except to entertain you ?

Have you never heard of mm^2 ?

Graham

 

[Martin Riddle]

Why do Americans persist in using stupid AWG that no-one else in the
world uses except to entertain you ?

Have you never heard of mm^2 ?

Graham

Forget how to convert Graham?

<http://www.engineeringtoolbox.com/awg-wire-gauge-d_731.html>

I don't think 10 awg will be a problem, as long as the # of turns is the
same. Measure the current to be sure.

Cheers

 

[James Sweet]

Why do Americans persist in using stupid AWG that no-one else in the
world uses except to entertain you ?

Have you never heard of mm^2 ?

Graham

You paint with a wide brush. I'd be perfectly content to use metric, and
end up using both systems regularly but it's not as if it's up to me
what the whole country uses.

 

[Eeyore]

Forget how to convert Graham?

<http://www.engineeringtoolbox.com/awg-wire-gauge-d_731.html>

I don't think 10 awg will be a problem, as long as the # of turns is the
same. Measure the current to be sure.

Oh I can convert. Trouble is, IME a single gauge can cover a range of
CSAs. Plus it's pointlessly and wastefully time consuming.

Graham

 

[Rich Webb]

Why do Americans persist in using stupid AWG that no-one else in the
world uses except to entertain you ?

Mostly inertia, of course. On the other hand, the AWG scale is right
simple to use to swag the nominal wire resistance, given that it's a log
scale and starting with AWG 10 = 1 ohm/1000 feet (yeah, "feet" but ...).

 

[Sjouke Burry]

You paint with a wide brush. I'd be perfectly content to use metric, and
end up using both systems regularly but it's not as if it's up to me
what the whole country uses.

And you dont care about the rest of the world?
If you want a clear answer ask a clear question.
Dont hide behind obscure local encodings.

 

[krw]

Now that is a helpful comment. Maybe because we are??? Why are there
three distinct classes of units in physics? (eventhough SI units are
somewhat universal). Cross sectional area and diameter are basic
parameters that engineers understand and taught to convert between any
system of units. Difference between an engineer and an hack? I like
blue, you may like purple. Our rocket went to the moon, you don't
have one...Sheese, don't ya have enough nits to pick?

Forget the dumb donkey. He's just another jealous Europeon.

 

[krw]

The subject excites you?

Only because 42 is the second number in that base.

Everyone knows that 42 is in base 13. ;-)

 

[krw]

That's enough arguing already! Lets compromise and use the FFF units system.

http://en.wikipedia.org/wiki/FFF_system

Or FSF (Furlong Stone Fortnight).

 

[Archimedes' Lever]

That's enough arguing already! Lets compromise and use the FFF units system.

http://en.wikipedia.org/wiki/FFF_system

I like the way Peter Sellers says "pressurized firkins" in "The Magic
Christian".

 

[Fred Abse]

Why do Americans persist in using stupid AWG that no-one else in the
world uses except to entertain you ?

Have you never heard of mm^2 ?

Metric magnet wire (enameled copper wire to you) is usually specced in
diameter, rather than cross sectional area.

 

[Fred Abse]

The coil in an industrial electromagnetic clutch (connecting the
flywheel to the drive mechanism) has gone open-circuit. So it is being
rewound by a motor rewind shop.

I was just informed that the original wire was about 12 ga.

"About 12 gauge" is hardly an engineering statement. Didn't they use
a micrometer?

Possibly 2mm diameter.


(maybe slightly

larger; original was metric) but it was rewound using 10 ga.

Should I be worried about this change in wire size? Will this change the
magnet's strength significantly? The current draw?

#12 wire is 2.053mm dia. #10 is 2.588.

Best practice would be to wind for the same number of amp-turns as before.

From wire tables, changing from #12 to #10 wire,the resistance of the same
number of turns will decrease by a factor of approximately 0.6. The
current will correspondingly increase by a factor of approximately 1.6,
hence so will the amp-turns, assuming the supply voltage stays constant.
How much the strength of the magnet will increase depends upon the
magnetic properties of the magnet iron. If the magnet was originally
operated close to saturation, the increase in pulling strength may not be
very much.

The power dissipated in the copper is proportional to current squared,
hence 1.6 for the same voltage. The coil will run hotter.

There's also the issue of supply regulation. Will the transformer supply
the increased current without significant voltage drop?


Why did they rewind it using #10? Didn't they have any #12? I'm surprised
they didn't have metric sizes, there are a lot of Japanese and European
motors around.

 

[krw]

You're wayyyy off base...

No, my position is pretty safe.

 

[Guest]

That's enough arguing already! Lets compromise and use the FFF units
system.

http://en.wikipedia.org/wiki/FFF_system

Gee, I thought it was the SFF system, stone, furlong, fortnight?

Otherwise agreed.
Any world wide "Standard"agreement is an extended version of what is going
on in Copenhagen- politicians and special interests drag it out indefinitely
as it is important to get ones first class travel to expensive
places -preferrably in a warm place with cheap booze.

 

[Eeyore]

You paint with a wide brush. I'd be perfectly content to use metric, and
end up using both systems regularly but it's not as if it's up to me
what the whole country uses.

The USA is 'supposed' to be metricated. hy you choose to be so backward never
fails to amaze me. Any given wire gauge covers a wide range of
cross-sectional areas. At least you know what you're getting with mm2.

Graham

 

[Eeyore]

Now that is a helpful comment.

It is indeed. AWG does not specify an explicit conductor CSA.

Maybe because we are??? Why are there
three distinct classes of units in physics? (eventhough SI units are
somewhat universal).

TOTALLY universal except for the USA, Liberia and Burma / Myanmar, both somewhat
backward countries you have chosen to retain compatability with. Some might say the
USA is rather backward too. The high level of belief in religion is one pointer to
that.

Cross sectional area and diameter are basic parameters that engineers understand
and taught to convert between any system of units.

Conversion is a waste of time and a source of errors. There is only ONE system of
units I need for engineering.

Difference between an engineer and an hack? I like
blue, you may like purple. Our rocket went to the moon, you don't
have one...Sheese, don't ya have enough nits to pick?

And what did you get from going to the Moon ?

Furthermore we have ESA
http://en.wikipedia.org/wiki/European_Space_Agency
and Galileo
http://en.wikipedia.org/wiki/Galileo_(satellite_navigation)

It knocks spots off GPS.

Graham

 

[Eeyore]

Mostly inertia, of course. On the other hand, the AWG scale is right
simple to use to swag the nominal wire resistance, given that it's a log
scale and starting with AWG 10 = 1 ohm/1000 feet (yeah, "feet" but ...).

Oh dear ! Is that how it was specified ? At what temperature btw ?

Graham

due to the hugely increased level of spam please make the obvious adjustment to my
email address

 

[Eeyore]

Metric is for people that have to count on their fingers !

What an absurd comment. Do you have 12 fingers so you can count in inches to the
foot ?

Graham

 

[Eeyore]

of course as any fool knows it should be either SWG or thousanths of an
inch

LOL ! Give me a thou over a 'mil' anyday. Only the Americans could confuse a
metric prefix with an old unit.

Not to mention that if you use the word 'mil' in the UK it means a millimetre.

Graham