120 and 240 Volt Motor Wiring


By Dave Rongey - Summary:

How to Wire a Motor for 240 Volts when the Motor is Designed for 120/240 Volts for Better Efficiency


How to Wire a 120/240 Motor for 240 Volts

Electrical Question: When wiring a 120/240volt motor is there any significant difference in power consumption 120v vs 240v, and any lose or gain in motor longevity?

This electrical question came from: Bruce , a Homeowner from Yosemite, CA
See more about Home Wiring for California

Dave’s Reply:
Thanks for your electrical question Bruce .

Wiring a Motor for 240 Volts

Motors that are Designed for 120/240 Volts

The Benefits of Wiring a Motor for 240 Volts When it is an Option

The Advantages of a 240 Volt Motor
Bruce, thanks for your question from Yosemite,CA – which is one of my favorite places to stay.  I just love Yosemite! Specifically Cabin 819 in Curry Village near the Awahnee Hotel which is the absolutely best place to be for Thanksgiving or Christmas.

The advantages of wiring a 120/240 volt motor for 240 volts is as follows:

IMPORTANT

RESOURCES

Electrical Wiring

For more information about 220 Volt Wiring Diagram
220 Volt Wiring Diagram
220 Volt Wiring Diagram
Wiring 220 Volt Electrical Outlet
Home electrical wiring includes 110 volt outlets and 220 volt outlets and receptacles which are common place in every home. See how electrical outlets for the home are wired.

This link is helpful as a Homeowner
Do-It-Yourself Electrical

How to Wire a Motor for 240 Volts



 
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6 Responses to “120 and 240 Volt Motor Wiring”
  1. Dave Rongey says:

    Old Robbins and Meyers Motor Wiring Diagram
    Hi William,
    Unfortunately I have not been able to locate a wiring diagram for your Robbins and Meyers motor.
    I would suggest visiting the Google Groups page where there is some discussion about Robbins Myers motor wiring.
    Here is the link: Google Groups Robbins Meyer motor wiring
    I hope this helps,
    Dave

  2. William Coveno says:

    Need Wiring Diagram for a Robbins Myers Motor
    I have a old Robbins & Myers motor. The plate reads, 110/220, 1725 RPM, frame S204, M/S 4470, SN AC111/94.
    There is no wiring diagram. There are 6 leads, all the same color.
    They do have numbered clip, 1, 2, 3, 4, 8, 8.
    What is the connections to run on 110 volts.

    Thanks.

  3. Dave Rongey says:

    Circuits for Two 120volt Motors

    Hi Timothy,
    Using a multi-wire 4wire circuit for two 120volt motors would depend on the type of motors that would be connected and the application. However, due to the amperage of the 120volt motors as described, and the possibility of overloading a shared neutral it would be best to install two separate circuits, one dedicated circuit for each motor.
    Dave

  4. Timothy says:

    Can I Wire Two 120volt Motors to a 240volt circuit?

    What if I have two 120v motors which operate at 14amps? I cannot run them on a single 20amp circuit.However, I have a 240 volt (4 wire) circuit which can handle much more amperage. If I was to wire one pole of each motor to the neutral and the remaining pole each to a separate hot wire (Having two 120v powers from one circuit) would that power each motor and not bust the amperage limit? Also, will there be any back-EMF effects through the neutral (which is shared)?

  5. Dave Rongey says:

    Hi Ed,
    If the existing circuit is dedicated, and the amperage is within the specs of the new motor then it can be converted to be 120 volt at the panel and at the motor connections. However, you should understand that the 120 volt motor will require more amperage, and this may affect the performance of the unit. In cases such as this it is best to replace the motor with one of the same specs to make sure the unit is left in OEM condition. This may keep you out of a potential problem with the customer in the future, plus you will not have to make any wiring changes. 😉
    I hope this helps,
    Dave

  6. Ed Lawlor says:

    I have a residential unit with a fan coil wired for 208/230 volt motor. I am replacing the unit with a 120 volt EC motor. Can I use the existing wiring circuit (use one leg) to power the new equipment? Did not want to increase customer costs with new 120 volt circuit home run.
    Thanks.