Fractional Horsepower (FHP) Motor Rotation

January 9, 2023

Motor Minute™ Technical Tip – FHP Motor Rotation

Hi, Chris from Regal Rexnord here with your Motor Minute technical tip. Helping you become an HVAC motor pro one minute at a time.

Today’s Motor Minute topic is Fractional Horsepower (FHP) motor rotation.

Determining the correct direction of the motor and/or the air moving device is important when selecting and/or installing a replacement motor. Even though most universal replacement motors are dual rotation, you still have to know which direction to select.

Motor rotation as it is listed on the motor, in Fractional Horsepower (FHP) direct drive applications, is confusing at best. There are many acronyms used to describe the motor’s rotation.

In fact, on some rating plates there is just an arrow.

If only CW or CCW is listed on the motor, you will need to look at the air moving device to determine rotation. Without a defining orientation listed on the motor, you are left to question which end of the motor to refer to. Unfortunately, there is no consensus among manufacturers.

• CW – Clockwise
• CCW – Counterclockwise

Adding a defining reference point makes the listed rotation more precise. The most widely used reference points are “Lead End” and “Shaft End”.

• Lead End (LE) references the end of the motor the leads exit from
• Shaft End (SE) references the end of the motor with the shaft

The following ratings all imply the same direction of rotation.

• CWLE – Clockwise Lead End
• CWOSE – Clockwise Opposite Shaft End
• CCWSE – Counterclockwise Shaft End
• CCWOLE – Counterclockwise Opposite Lead End

All of these ratings imply the same direction of rotation, in the opposite direction as shown above.

• CCWLE - Counterclockwise Lead End
• CCWOSE – Counterclockwise Opposite Shaft End
• CWSE – Clockwise Shaft End
• CWOLE – Clockwise Opposite Lead End

It will take some practice, but once you think through each word of the rating, it will begin to make sense.

Understanding the correct rotation is critical if you are replacing with a dedicated rotation motor. If you are replacing with a dual rotation motor, knowing the correct rotation of the air moving device will help you set up the motor to operate in the proper direction of rotation, the first time. Thus, saving the time required to reverse the motor after it has been installed or replace it with the correct rotation motor.

If the direction of rotation is not listed on the failed motor or is not legible, you will need to determine the direction of rotation of the air moving device.

This information will be covered in future Motor Minute tech tips as listed below.

• Indoor Blower Motor Rotation
• Outdoor Fan Motor Rotation

And that’s a wrap on this segment of Motor Minute technical tips. Remember that we provide motor training and product information in multiple formats including videos, literature, podcasts, articles, of course Motor Minute technical tips and classroom education both online and face to face. All of this industry leading training is available at no charge to HVAC professionals at regalmmu.com. Thank you for taking the time to build your motor knowledge.

View fractional motors from Regal Rexnord.