Author Topic: What does IN-HAND mean?  (Read 3741 times)

Offline Ivan

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What does IN-HAND mean?
« on: December 13, 2012, 10:49:49 PM »
A big question I had when I started looking for an AC 3 phase motor for electric vehicle was, what is the difference between an off the self (a stock industrial AC motor) and an electric vehicle AC motor?

Motors designed for electric vehicles have to handle 3 to 4 time the current than an industrial motor (winding). Most 10hp, 15hp and 20hp industrial motors would have a max current rating of 20 to 40 amps max continuous.

Most electric vehicles need 80 to over 100 amps of continuous current to move the vehicle at a steady speed of 50 plus mph. (I am talking of vehicle weights of over 2000 lbs.)

So back to the original question?  what is the difference?

It is the in-hand (wires) used to make up the coil set. These are the main leads going into the motor that has to handle the high currents (amps).
 
My 10 hp motor originally had 3 in-hand and used 10 turns, But the motor is only rated at 25 continuous amps. Will 3 number 18 gauge wires handle 80 plus amps continuous?  Not for very long..

Let me explain the term in-hand.  When the original motor coils were wound, you would take 3 spools of wire (lets pick a gauge, 18) and take all 3 ends from the 3 spools of wire to make the coils (that would be called-3 in-hand).

So in conclusion, just think of in-hand (more in-hand) as going from a small wire to a much bigger wire, to handle the higher current (amps).

This is the number one reason a 3 phase ac industrial motor needs to be rewound for use in an electric vehicle. (Large in-hand/large motor leads)

The number two reason to rewind an EV motor is for it to match the voltage curve for a specific controller.


Stay tunned,  more to come..

:co<:  If you bought just one or two extra can goods a week and donated to a food bank   Nobody would go hungry.

Offline piotrsko

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Re: What does IN-HAND mean?
« Reply #1 on: January 01, 2013, 08:04:15 AM »
OK dumb question then:  Why not just increase the circular diameter of the wire by 3 X  or to whatever size wire that will carry the proposed currents?

Offline evsam

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Re: What does IN-HAND mean?
« Reply #2 on: January 01, 2013, 08:32:23 AM »
OK dumb question then:  Why not just increase the circular diameter of the wire by 3 X  or to whatever size wire that will carry the proposed currents?

That is kind of the same thing.  You only have so much slot space.
So 3 times the wire size then 3 times less wires, if that makes sense,
ie.. equals the same circular mills going in the slot.

Sam

Offline Ivan

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Re: What does IN-HAND mean?
« Reply #3 on: January 01, 2013, 09:40:30 AM »
OK dumb question then:  Why not just increase the circular diameter of the wire by 3 X  or to whatever size wire that will carry the proposed currents?

That is kind of the same thing.  You only have so much slot space.
So 3 times the wire size then 3 times less wires, if that makes sense,
ie.. equals the same circular mills going in the slot.

Sam


Good job Sam


I would like to add, going to a bigger wire you reduce the resistance
plus you would change your voltage curve.


The bigger wire does not nest together as tight as smaller wire,
thus less wires in slot, less cir-mils inhand.

:co<:  If you bought just one or two extra can goods a week and donated to a food bank   Nobody would go hungry.

Offline arlo1

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Re: What does IN-HAND mean?
« Reply #4 on: February 28, 2013, 09:25:55 AM »
So to be simple the number of In-Hand wires is simple the number of parallel wires.  In-hand=Parallel.

Offline Ivan

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Re: What does IN-HAND mean?
« Reply #5 on: February 28, 2013, 01:30:44 PM »
So to be simple the number of In-Hand wires is simple the number of parallel wires.  In-hand=Parallel.

Call it what you want, but the term is in-hand, how many wires are in your hand to make, wind the coils.
:co<:  If you bought just one or two extra can goods a week and donated to a food bank   Nobody would go hungry.

Offline mizlplix

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Re: What does IN-HAND mean?
« Reply #6 on: February 28, 2013, 03:51:23 PM »
In Hand is an old motor shop term.  They know what you are talking about if you use it.  They will think you are retarded if you try to use anything else to describe it...LOL

Just one of those things....

Miz
1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.