Reversing AC motor rotation


  #1  
Old 03-06-15, 11:49 AM
H
Member
Thread Starter
Join Date: Mar 2015
Location: USA
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Reversing AC motor rotation

Similar questions have been asked here before but didn't address my particular problem. I have a new split phase AC motor (for drill press) that I need to reverse the rotation of. The motor is constructed so that reversing rotation is easily accomplished. It even says right on the motor that to reverse rotation, switch the red and black leads. Everything easily accessible. No problem. Simple, right? Except that switching the leads does not in fact reverse the rotation. I've switched them back and forth 5 times now and it always rotates in the same direction; the wrong way. So my question is: what is causing this? And what can I do to rectify the situation?

Craftsman Split phase AC motor. 115V 60 HZ 1/3HP Model #113.12037
(Getting knowledgeable help from Sears has proved impossible)

Thanks in advance----
 
  #2  
Old 03-06-15, 12:37 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 63,820
Received 3,745 Upvotes on 3,359 Posts
Welcome to the forums.

The red and black lines connect to the start winding. If the motor is already spinning.... reversing those wires will do nothing.

The motor must be started with the wires reversed.
 
  #3  
Old 03-06-15, 01:15 PM
Rough Rooster's Avatar
Member
Join Date: Feb 2014
Location: USA
Posts: 403
Received 16 Upvotes on 12 Posts
Look at the motor wires and see if you can find two wires with labels stating T5 and T8. If so swap their positions and your motor will run the opposite direction.
Most likely the red and black leads are the input voltage.

Good luck!

RR
 
  #4  
Old 03-06-15, 05:53 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 63,820
Received 3,745 Upvotes on 3,359 Posts
The red and black wires are indeed the start winding.

Name:  motor.JPG
Views: 491
Size:  38.9 KB
 
  #5  
Old 03-06-15, 06:15 PM
Rough Rooster's Avatar
Member
Join Date: Feb 2014
Location: USA
Posts: 403
Received 16 Upvotes on 12 Posts
Learn something new every day!

(since I am old my info is old )

RR
 
  #6  
Old 03-06-15, 08:32 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 63,820
Received 3,745 Upvotes on 3,359 Posts
Maybe... but with age comes knowledge.
 
  #7  
Old 03-07-15, 11:30 AM
H
Member
Thread Starter
Join Date: Mar 2015
Location: USA
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
So my question is, what would cause it to not reverse when the leads are reversed (the motor is unplugged and stopped when the wires are switched). As the picture below depicts, the wires to be switched are clearly illustrated. Could it have anything to do with the house wiring?
 
  #8  
Old 03-07-15, 11:42 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
Could it have anything to do with the house wiring?
No. What kind of reversing switch are you using? How is it wired?
 
  #9  
Old 03-07-15, 09:21 PM
H
Member
Thread Starter
Join Date: Mar 2015
Location: USA
Posts: 3
Upvotes: 0
Received 0 Upvotes on 0 Posts
Not a switch. Reversing starter leads. Typical split phase wiring.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: