Tip & How-To about Dryers

How to Reverse the Rotation of Single Phase Capacitor-Start Electric Motors

Reversing the rotation of electric motors can be done easily with 3-phase motors. This can be easily achieved by swapping the connection of any two motor leads. But 3-phase motors are usually found and used for industrial purposes. The ones found and used in our homes, from water pumps to electric fans, are single phase capacitor-start type motors. Unlike 3-phase motors, reversing the rotation of single phase electric motors is no easy task. Swapping any two motor leads will not result in the reversal of the motor rotation. Analysis of the motor windings and connections are necessary before any modification can be done to achieve the desired result. Let's take a 3-speed single phase capacitor-start electric motor with electrical diagram shown below as an example. Make sure the motor is disconnected from the power supply before attempting to follow this tip. This tip is intended only for individuals with electrical knowledge, necessary tools, and understand the risks associated with handling electrical equipments and devices.



The first step in the process is determining the start winding which is connected to the line (AC white) and to one side of the start capacitor. To accurately determine the start winding, disconnect all motor leads from the start capacitor and the speed switch for multi-speed motors and then setting your ohmmeter to the lowest scale (R x 1), measure the resistances between the AC white line and each of the motor leads connecting to the start capacitor. The one with the least resistance is the starting winding lead.

Once the start winding lead going to the capacitor is determined, reconnect the capacitor then connect the black AC line to the found start winding lead (marked X). Connect the white AC line to L of speed switch, the motor lead formerly connected to AC white to 3, red to 2, and white to 1 as shown below. Leave the green/yellow ground wire connection as is.




Below are the wiring modifications for 2-speed and single speed single phase capacitor-start electric motors.













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I have a Hobart h67 passthrough dishwasher is the pump motor 3 phase wondering for phase rotation reasons don't want it running backwards


If m3 phase the possibility is for the motor to run backward depending on lead connections. If you replace motor wire it up and press contractor and close power contacts let go and observe motor rotation. If needed to change rotation switch lead 1 and 3. When I installed pumps I removed coupling to run motor..

Mar 18, 2018 | Hobart Dishwashers

1 Answer

I have a 1 1/2 hp 230/110 marathon single phase motor controlled by forward reversing starters with 24 volt controlled. How do I wire this motor up for for/rev ???


You need to determine at which voltage you will run this motor. A motor starter mechanically and electrically interlocked for F & R. with 24v transformer, a SS and FR station. This is expensive but sweet, needs room for this equipment.
The easy budget is by using a drum switch.
The motor nameplate or splice box cover will hand the info on how to connect the motor for either voltage and for CW and CCW rotation.
The magnetic motor starter also will include a wiring diagram.

Nov 04, 2017 | HP Air Tools & Compressors

2 Answers

I have Hobart D300 mixer which operates at 220V, 3phase supply and whereas the facility has 208V, single phase supply. Is there any recommended phase converters available for this product. Thanks


Hi Bill
I may be wrong here......
But I've been around Electricity for a long time.
Have Never seen a device that does phase conversion.
A Building site or home will either have Three Phase or Single Phase Power Available
BUT...A portable (Hired) generator could be "three phase" and you could use any one of those phases individually or all three phases.

I have 3 Phase supply to my house!
But I use 230 volt Single Phase for appliances.
My Bore Pump uses a 3 Phase Motor,
(so with a voltmeter it would read about 440 vAC to the pump motor).
Some Further Info:
A GENERATOR is basically a motor used the opposite way. Rotate a motor and it Generates.
The Phases refer to the THREE Windings in the supplying generator in your suburb.
A Large Magnet passes each winding in sequence giving you the three ripples in the supply.
Our houses can choose to have 1 Phase or Three Phases from the street when you set up your electric supply.
So... to confirm, look at the wires on the supply poles to the premises. Usually three in our area (Oz)
Most people are not aware that a car Alternator is actually three phase. The Rotor is the magnet that rotates.
The only difference with an Alternator is that each "Phase" is connected to 2 Diodes (6 total) to convert the three phase to DC to charge the vehicle.
The Regulator controls the voltage to the Rotor, thereby controlling the output.
So.... An Alternator could in theory supply 3 Phase in a mobile generator. Custom Made. Constant speed would determine the frequency of 50Hz or 60Hz.
Not sure what country you are in

Hope this Helps or gives you food for thought!


Three phase electric power

Jul 08, 2015 | Hobart Food Mixers

1 Answer

how do I reverse a three phase electric motor?


Reversing rotation of 3 phase motors:
CAUTION: Before attempting any repair of electrical equipment verify the power is disconnected to the device.
CAUTION: Three phase motors could potentially be controlled by frequency control systems. It is recommended a trained electrician perform repairs to any electrical system. In particular, consult a trained electrician if the system includes a frequency control system.

Most 3 phase motors can reverse rotation simply by swapping any 2 of the 3 phase wires. A typical 3 phase wiring circuit will include a safety ground wire (usually green) and 3 phase wires, often designated A/B/C, or 1/2/3, or color coded to distinguish each. By swapping the terminal connection of any 2 of the three phase wires, for example, 1 & 2 or 2 & 3 or 1 & 3, but leaving the third phase wire unchanged will reverse the rotation of most motors.

Jun 12, 2014 | Hayward 1.5hp Pool Pump Motor Motor A O...

3 Answers

electric motor make, lamco, model no.EC34-1(93) reversing 120v 16.5amps


Here are electric motor links that might help.
Or not.
http://waterheatertimer.org/Color-codewire.html#motor

You have to test the windings with multimeter to identify start winding, vrs run winding.
Both windings receive power at same time.
The start winding is like first gear on a car. It starts the motor rotation.
The run winding brings motor up to rated speed.

Sometimes categories at Fixya are muddied, and people do not say which product they have, or give UL number instead of product number, and sometimes fixya questions are truncated onscreen ... so person answering question thinks the product is a gasoline powered bobcat, instead of hybrid car, or 120Volt single-phase electric motor.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Nov 25, 2012 | Hardware & Accessories

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