# 220  Vs 110 motor choice



## joebiplane (Mar 30, 2011)

My 1945 logan 820 lathe has a Peerless motor which is likely the origional motor and it can be wired for 220 or 115 . it is presently wired for 220 and i could change the plug to match my 50 amp connection that I had installed for my elect welders or I could re-wire the motor for 115 volts and use a standard 20 amp available outlet which would be a bit more convenient . My question is which voltage would be preferable for powering the motor ?  I am not concerned about the cost of electricity as i only use the machine for my seriously addictive hobby. and I cant imagine the cost to run the lathe could be significant.
Survey SAYS[size=24pt]......?  :-\[/size] 
Thanks.....


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## pdentrem (Mar 30, 2011)

If it is under 1 hp it likely does not matter. My cabinet table saw has a dual voltage motor as well, but at 3 hp it is easier to run at 220 with the house wiring that I have. The lights do not dim when I start it up. 8)


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## Highpower (Mar 30, 2011)

I'm no electrician, but I _think_ it is easier on the motor windings being run at 220V? Less amperage at least.
Maybe smoother running as well? (Thinking surface finish here...)

I'll leave it to the experts to shoot down my theory.  ;D


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## Tony Wells (Mar 30, 2011)

Once a motor is running, there isn't a lot of difference. Startup will be better with 220. Cost is the same. That only comes in with 3 phase. Given a choice, I always wire things at 220. 

Be careful. A 50 amp welder circuit should not be used with a lower current motor. You need to size the breaker to suit the lathe motor. You didn't say what hp it is, so I can't advise on that. If you run it on a 50 amp circuit, and have a problem, you won't have proper protection. 

If this is truly hobby use, wire it for 120, give it it's own circuit (or make sure it is the only thing running at the time the lathe is in use), and make sure the breaker and wiring is correct for the motor draw.


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## Starlight Tools (Mar 30, 2011)

As a dual voltage motor consists of three windings, two run and one start, and as the run windings are either in parallel for 110V or Series for 220V and the start winding is in parallel with one of the run winings, all any of the windings see is 110V. 

Since each winding will draw the same amount of current based on its using 110V and the power that the motor consumes is identical in watts (volts x amps = Watts) and based on this it does not matter, either from a starting or a running stand point whether you wire the motor 110 or 220V.

This is true for motors up to about 1-1/2 HP.

Over 1-1/2 HP we start to see another factor crop up. The total amperage in the wires that feed the motor start to get above 15A which most common household circuits can handle. If we run the same motor on 220V, even though the total power in watts is the same, it is now split between two current carrying conductors, at say 7.5 Amps each so that smaller wiring and smaller breakers can be used. It also balances out the currrent load on the main panel better.

As we continue to get larger in motor size the combined current gets to be excessive for a 110V circuit and the motors become single voltage 220V motors.

Next we have to content with that 50 Amp breaker.

The breaker is put in to protect the wiring. It really does not protect anything that is connected to the wiring. If it is a 15 Amp breaker can use up to 14 Ga wire, a 20 Amp breaker up to 12 Ga wire and by 50 Amp it is going to have at least no 8 wiring. Look at a small item that draws only an amp and is plugged ito a 15A circuit, It will fry long before the 15A breaker trips. A motor that draws under 15 Amps being run on a 50 Amp circuit means that the motor is not being protected at all.

Most motors need a seperate circuit breaker or thermal relay built into the device to protect them from high current. so can you use the 50Amp circuit for your motor, yeah probably, but make sure that the motor is protected by some form of breaker that is sized for it and the wiring in it.

Walter


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