# 115/220



## Bill Gruby (Nov 17, 2012)

The Clausing 8520 I brought home today has a Hoover Motor on it. It is dual voltage. What if any disadvantage is there if I run that motor on 120 house current? It is now set for 220 single phase.

"Billy G" :thinking:


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## refinery Mike (Nov 17, 2012)

the disadvantage is that you will have to supply twice as much current, twice as big a breaker, twice as big wire to it. I do not know just how much power we are talking about but that is the general reason for going to 220 over 115.


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## Kennyd (Nov 17, 2012)

^^^^^^^
What Mike said.


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## Bill Gruby (Nov 17, 2012)

Thanx to both of you. I will just run a 220 drop and have at it.

 "Billy G" )


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## Cal Haines (Nov 17, 2012)

Bill Gruby said:


> The Clausing 8520 I brought home today has a Hoover Motor on it. It is dual voltage. What if any disadvantage is there if I run that motor on 120 house current? It is now set for 220 single phase.
> 
> "Billy G" :thinking:


It depends on how big the motor is.  You can run a 2HP motor from a 15A, 120 outlet.  A 20A circuit can handle 3HP.

If you change the voltage you'll need to change the overload protection for the motor.  Depending on the starter you may need to replace little coils called heaters to change the overload current.  If you don't the machine will trip the overloads at about 25% of full power.  If there are fuses you will probably need to change those as well.

_Cal_


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## wa5cab (Nov 18, 2012)

Billy,

If running a dedicated 240 volt drop is practical, I'd do that.  Then you don't have to worry with any other considerations.  You didn't say what HP your motor is but the Clausing 8520 manual says 1/2 or 3/4 HP is required so probably one of those.  Whether you can run those on an existing 120 volt 15 amp (or 20 amp for that matter) circuit depends upon what else is already on the circuit.  My shop, formerly know as the detached garage, has its own 60 amp feed and as I did all of the wiring in it, I set it up with dedicated circuits for lighting, wall outlets, AC/heat and fixed location equipment.  But your situation may be different.  If you decided to rewire the motor for 120 VAC, and run it on an existing 15A or 20A circuit, you would need to find out what else was on the circuit and consider whether any of it would be running at the same time as the mill.

Theoretically you could in fact run a 3 HP motor on a 120 volt 20 amp circuit.  3 HP mechanical converts to 18.65 amperes electrical @ 120 VAC.  But that assumes 100% efficiency in the motor and capacitor start single phase motors are notoriously inefficient.  A quick search on Grainger turned up only one 3 HP single phase.  It's FLA is 33.8 for 57.8% efficiency.  That is quite good efficiency for a single phase capacitor start motor.  Several smaller motors I looked at are even lower.  And it also depends upon how hard the load is to start.  Fortunately, a mill can generally be considered easy starting as there isn't usually much mass to accelerate.  

Robert D.


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## Bill Gruby (Nov 18, 2012)

1/2 HP  115/220 volts 7.8/5.3 amps  That is off the motor plate.

 "Billy G"


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## Tony Wells (Nov 18, 2012)

Unless the circuit you intend to use is nearly at capacity, I'd go with the 110/115 and leave it at that. 8 amps is not going to be a problem.


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## wawoodman (Nov 18, 2012)

A 1/2 HP can run on a 110/15A circuit with no problem, as long as there isn't too much of a load on that circuit, already. So it comes down to, is it easier to run a 220 drop, or rewire the motor and change the plug?


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## Terrywerm (Nov 18, 2012)

I've got an 8520 with a 1 HP dual voltage motor. When I got it, it was supposedly wired for 220, and the cover was missing for the junction box on the motor. A couple of the wires were hanging out. RED FLAG!!   I don't know how the previous owner was even using it, as it was wired in a manner that would not allow it to run on either voltage. I began to suspect that the motor might be toast, and it was obvious that the machine had not been used in a long time. So, I assumed that the motor was probably junk and accepted the fact that I may have to buy a motor. Before doing so, I decided instead to rewire for 110 V and test the motor and drum switch. Figured out the correct wiring, did it all up and BINGO!  It worked just fine. Since I am currently planning to move my shop to a room in my basement, I am leaving the machine set up for 110 so that I do not have to run a 220 drop. It works just fine on 110 V and I see no reason to change it for my purposes. So, mine will stay on 110 for now, but I can always change it if necessary.


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