I want to reverse rotation on my A.O. Smith 120/230 volt single phase 1.5 HP motor. Catalog number B762

Either the run or start windings must be wired opposite the existing configuration. Single (split) phase motors for compressors typically don't bring out the taps to allow reversal. Check the name plate as it will likely say non reversible.

Instructions about how to reverse a motor is often pasted under the terminal cover.
A single phase motor will run in either direction and it is the kick from the phase shift caused as the capacitor charges through the start winding that dictates the direction.

The identity of the wires aren't always clear, especially with multi-voltage motors but reversing the connections to the start winding will reverse the direction of rotation.

Changing the "polarity" of the start winding by swapping the wires over should reverse the direction. Lots of online motor-related generic and manufacturer information is available.

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.

Single Phase Terminal Markings Identified By Color: (NEMA Standards) 1-Blue 5-Black P1-No color assigned 2-White 6-No color assigned P2-Brown 3-Orange 7-No color assigned 4-Yellow 8-Red

I'm not sure which motor you have - the heading shows a 1HP type - yet you talk about a 2HP type. Anyway, the label on the motor should have a wiring diagram. You must have a label on the motor to know how to wire. It may have two diagrams - one designated as "high voltage" and the other "low voltage". Check the label for voltage.. it likely says "120/240 volts". The 120 uses the low volts diagram and the 240 uses the high volt diagram. If the motor has terminals L1 and L2, these will most likely be the point of connection for power - regardless if it 120 or 240, unless the label states otherwise. Unless the neutral connection is specified on the label, it does not matter which L1 or L2 you connect it to.

The other terminals will be required to be connected properly. Motors use these connections or jumpers to set options such as voltage, direction of rotation, speed(s), etc. An incorrect setting here can cause unexpected results as far as speed and rotation, or catastrophic results if you supply this motor with 240 volts but set the jumper for 120 volts.

Here's a link to their catalog with telephone numbers for you to review.

Good luck!

Thank you for posting your question here on Fixya.com.

I am not sure what you mean by "center wire". For 230V single phase you should have 2 hot line leads (115V each) and a ground wire. Set the motor leads as the nameplate shows for the high voltage connection and attach your line leads where the two lines are indicated. If you have a 3+Grd wire drop DO NOT connect the neutral, insulate it and leave it unconnected. It will not matter which line lead connects to which motor line wire as far as rotation direction. To change rotation, if the motor allows it, you reverse the start winding leads as directed on your nameplate.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!

John

I assume you have 3 phase power where this is going? The panel has 3 legs, 2 are 110 volt and one is 208 volt, you will need a tester to find out which is which if it is not marked, the motor should have a map on it for the wires to attach to, they go the same way, two, 110 and one, 208, I hope this helps, There will be one wire for a ground or a solid wire separate from the unit.

First, take the plate where the wires connect to the motor off, and the solution is normally found in the dust cap for the wiring. If not there, go to the AO Smith website with your motor model number and there should be instructions on which of the numbered leads to group together in order to reverse the rotation. Don't worry- it's easy. Don't forget to unplug everything before changing these wires around.

You will either need a phase rotation meter to identify the rotation, or, if it is a motor, reverse any two leads to spin the motor the opposite direction (this works on single phase, too).

i hope this is helpful
matthew