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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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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.

Nov 25, 2012 | Hardware & Accessories

1 Answer

how to reverse rotation on type k4120 3 phase motor?


hello

make note of positions of wires and colors before moving and wires so can be put back if need to

in general 3 phase motors can be reversed by reversing only one of the phases that come in

as far as i know forward rotation sequence would be red, yellow, blue , (these are the 3 phase wires and could also have a black wire nuetral if the motor is a unbalanced load motor

but think that phase color blue is now white according to electricity regs for 3 phase motors

if the motor is a balanced load motor it may not have a black wire
.
(the function of the nuetral conductor is to to carry the out of balance current if the loads on each of the 3 phases is diffenent ) and of course has a earth wire as well ( which is yellow/ green )

you should reverse either red and yellow position only or yellow and white position only

but if in doubt check with your local electrcian to confirm
always check electrcity regs before altering

cheers






May 29, 2011 | Garden

1 Answer

wiring diagram for 230v


Single phase motor for 230V, connect T4 and T5, to one line. T2, T3, T8 common connected. T1 to other line. Check Rotation, This should be for CCW rotation facing output shaft. Swap T5 and T8 for CW rotation.

Jan 17, 2011 | Ingersoll Rand TS4N5 Ir Electric...

1 Answer

need to rewire from 480 to 240 need coolant pump diagram for colchester # 348337 3 phase motor


Assuming that the motor has 9 leads and the wire numbers are still on the wires, for 240 volt 3 phase connections:

Connect T1, T6, and T7 together with L1 (A phase)

Connect T2, T4, and T8 together with L2 (B phase)

Connect T3, T5, and T9 together with L3 (C phase)

If you're not sure which of the incoming wires from the supply are L1, L2, and L3, just pick one. If the rotation is wrong just swap any 2 (TWO) phase wires.

Jun 22, 2010 | Measuring Tools & Sensors

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