# How do I rewire or convert a  115volt to 230 on Emerson 1HP motor single phase



## Johndrew (Jan 11, 2012)

I have an enclosed Emerison 1hp motor single phase, which is reversable. It has two capacitors on the top but no diagram. Attached is a diagram of the terminal plate I drew.

1. POWER ( White power comes in on terminal 1 and black power comes in on terminal 4)
2. Terminal 2 is empty

3. Red is on terminal 7
4. Black and white are on terminal 3
     (Exchange the red and black, to make the motor reverse)

5. Terminal 5 is empty and near the red wire mentioned below
6.  There is a red motor wire which does not attach when on 115 volt


How do I convert it to run on 230 volts? There is no label on the motor


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## Tony Wells (Jan 11, 2012)

Is there a part number on the motor anywhere?


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## Johndrew (Jan 11, 2012)

Tony Wells said:


> Is there a part number on the motor anywhere?



Nothing on it but Emerson Economiser and a bad bar code. I used a tach to determine the RPM and a amp meter draw and the frame size, capacitors and shaft size  to estimate the HP. I went to www.usmotors.com and looked for a dual voltage single phase but did find one with the correct number of wires.


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## pdentrem (Jan 11, 2012)

Not all motors are dual voltage. The dual voltage motors change the running coils from parallel for 110 to series for 220. You can check the windings with a good ohm tester. The running coils are the same resistance and the starting coil will be significantly different. The starting coil is 110 volt and is connected to the center between the two running coils. It's connection is not changed. Only the running coils are.

But based upon your diagram I believe you are out of luck. Check to see if there is any connection on 2 & 5 at all. A motor shop can answer this question very quickly.


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## Johndrew (Jan 11, 2012)

1. There are no wires on terminal 2 
2, None on Terminal 5

Looking at the photo, the brown motor  wire appears to be designed to attached to terminal 5 because of the length and  location near terminal 5

The black and red reverse the direction.  

To test the ohms, what wires should I connect to? 

Power Black
Power White

Red
Back
White
Brown


Looking deeper inside (see attached) 
	

		
			
		

		
	



	

		
			
		

		
	
 I see a Orange, red, black, white, and yellow wires. Would this indicate a 230volt motor?


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## Pacer (Jan 11, 2012)

I dont believe that motor is dual voltage capable either - I had a couple, that, if memory serves me, had that wiring set-up and they wernt dual voltage. That type of mount is - generally - used in light duty applications such as fans and wouldnt have dual capibility.


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## pdentrem (Jan 11, 2012)

In my motor book and doing a search as well, usually dual voltage motors have 6 wires vs 4/5 wires single voltage.

You can also check the motor case for stamped numbers. The mounting is light duty as stated by Pacer.


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## Alan Douglas (Jan 12, 2012)

I'd be surprised if that is more than 1/2HP.  But then, I've been surprised before.  Is there a note on the motor to reverse the two wires to reverse rotation, or did you find that out by experiment?

You may have to take it apart to find out where those extra wires go.  That's not difficult; you just need to match-mark the end bells and stator so you can get it back together properly.


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## pdentrem (Jan 12, 2012)

Based on USMotor site the Brown wire is likely for thermoprotection. Plug the motor in and check the draw. 750 watts equals 1 hp.


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## Alan Douglas (Jan 12, 2012)

I think you'd need to load it on a dynamometer to maybe 1725 RPM to determine horsepower from the current draw.  Size and weight compared to similar motors is probably close enough.


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## Johndrew (Jan 13, 2012)

pdentrem said:


> Based on USMotor site the Brown wire is likely for thermoprotection. Plug the motor in and check the draw. 750 watts equals 1 hp.


 I have a snap on ampmeter and will check the draw


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## Johndrew (Jan 13, 2012)

This is a picture (attached) of a Emerson 2hp motor and the terminals are the same as the motor I have. The 230 hookup (right side in picture) is what I have now and it is running on 115 volts????.  Would this same hookup run with 230 volts?

Should the 115 volt be hooked up like the diagram on the left (115volt)??

I got 3 of these at a auction for $5 each but there is no information other than Emerson. With these was a Dayton 1hp, single phase, two capacitor, 115/230 ballbearing enclosed with a 56 frame but 3450 rmp vs 1725. I used a tachometer to determine the rpm. Looks the same type of motor except for RPM. They company removed the labels on the Emerson and the diagram from the Dayton.


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## pdentrem (Jan 13, 2012)

Give it a shot. For 5 bucks really nothing to loose.


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## Alan Douglas (Jan 13, 2012)

A 3450 rpm (2 pole) motor will be somewhat smaller physically than a 1725 rpm (4 pole) of the same horsepower.


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## Johndrew (Jan 13, 2012)

It worked.. The brown wire is not used on 230 volt but is used on 115 volt.

I hooked up a A. W. Sperry Rand snap on amp meter. I set the range to 20a and got 5.0.

How many watts would that be?


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## pdentrem (Jan 13, 2012)

Volts times Amp equals Watts


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## Alan Douglas (Jan 13, 2012)

But a lot of that 5 Amperes is inductive and doesn't represent real power.  A Kill-a-Watt would probably tell you how much (I think it can read power and power factor, the same thing expressed differently).  But unless the motor is under load, it only draws enough power to overcome bearing friction, windage, copper and iron losses.


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