Can I reverse direction on a single phase motor

R

Randydb

Joined
Sep 27, 2014
Messages
1,104
Please forgive me for my original post that said the wrong hp for the motor...I was trying to post from work and messed up the nameplate too. That's the problem when I am texting my wife asking her to take pictures of motors on tools and not really thinking through what I have done too. So correct info...

I found a 3/4 hp single phase motor for $50. I plan to put it on my 6x48 grinder which also has a 9" disc sander on it too. But the motor is running backwards from the old 1/4 hp motor that is on there now.

Can I do anything to reverse the direction the motor runs?
 
Last edited:
Yea you can, it's what I did with the 1 HP I got from Harbor Freight. Not able to help you out with wiring though, I just remember having to switch two wires around on mine to get it to run from CW to CCW. I'm sure somebody here will help ya out with the technical stuff.


~Paul
My Youtube Channel
... (Some older vids of some of the older knives I made)
 
It is usually on or underneath the cover plate. Switch two wires to different positions. You either switch the starter winding leads, or the running winding leads. DO NOT switch both.
 
Read the data plate, some easily do it

instructions for cw and ccw

or to reverse swap red and black lead


Some don't
 
Mount the motor in the other direction. It won't fit where the 1/4 HP was anyway.
 
Bill DeShivs said:
Mount the motor in the other direction. It won't fit where the 1/4 HP was anyway.
Click to expand...
I've got it fitting just wonderfully...it took drilling 4 new holes in the mounting part of my stand. It would hang in space if I tried o mount it in the other direction.
It has a switch built into the motor. So no real cover plate to speak of. I'm sure the wires you guys are speaking of are under the switch. I will do some looking and picture taking when I get home and ask for some advice when I can show you what I have.
 
1.5HP with built in switch and no cover plate? Show us a photo. I bet the switch is mounted on the cover plate.
 
Lets see pictures. Nameplate and endplate where electricals are located.
Some motors are not made to be reversible.
(It not saying they cant be reversed. Thats just a matter of motor surgery whats beyond the scope of this discussion)
 
I posted wrong info here.....correction made with proper info a couple posts down from here.
 
Last edited:
Many motors have a wiring diagram on the nameplate itself, OR a brief instruction for reversing rotation (i.e., which leads to swap). There may be a diagram under the peckerhead cover as well, which may be where the switch is located.

Here's more than you ever needed to know about reversing motors:
https://woodgears.ca/motors/reversing.html

Some do specifically say "non-reversible", but that's more of a "not EASILY reversible". ;)
 
Okay....please forgive me for posting so many things wrong in this thread. I have taken pictures now and I the info is corrected here and in the other posts here. I feel stupid for screwing up, but I am hoping you will still help me get this motor running in the right direction....please. I understand if you call me names or don't answer. That happens from time to time around the house here too. If I didn't know better I might think my middle name was Dumbass at times.

It is a single phase 3/4hp motor. Here are some pictures. I want to get it running in the opposite direction that it runs now.
IMG_2246.jpg IMG_2245.jpg IMG_2247.jpg
 
I did a search on Prestolite-Leland Motor Reversing and found some info:
CCW - single voltage:
Orange - line
Blue, Red
Black, Yellow - line

CW - with protector:
Orange - line
Blue, Black
Red, Yellow - line

I would do some more searching with your exact model number and double check.

ALSO, READ THIS:
https://www.groschopp.com/how-to-reverse-ac-motors/
 
So where are these wires found? The other 4 electric motors on tools of mine have a cover plate that I take off and I can see all the wires. I don't see any cover plate on this motor.
 
They are either under the switch or under the info plate. The plate rivets are just driven in and can be pried out.

Just out of curiosity, have you run this unit with the switch in the opposite position? it may be a reversing switch, as I have seen on some older motors.
 
Check the photos, Jesse. This old Prestolite motor is different than a modern one. The wires enter under the switch. It may e an ON/OFF switch, or a reversing switch. I had an old motor when I was a kid with a built in reversing switch.
 
Stacy E. Apelt - Bladesmith said:
They are either under the switch or under the info plate. The plate rivets are just driven in and can be pried out.

Just out of curiosity, have you run this unit with the switch in the opposite position? it may be a reversing switch, as I have seen on some older motors.
Click to expand...
I removed the "toggle" on the switch and checked....it only is on/off....not reversing. I also pulled the cap off where the wires go in. There is just holes where they come through the housing.
SO do I need to pull the 4 nuts on the switch end of the housing next? Or pry off one of the plates and see what is behind there? The plates are on the housing on the opposite end from where the wires come in.
IMG_2252.jpg IMG_2251.jpg IMG_2253.jpg
 
Randydb said:
I removed the "toggle" on the switch and checked....it only is on/off....not reversing. I also pulled the cap off where the wires go in. There is just holes where they come through the housing.
SO do I need to pull the 4 nuts on the switch end of the housing next? Or pry off one of the plates and see what is behind there? The plates are on the housing on the opposite end from where the wires come in.
View attachment 1241517 View attachment 1241518 View attachment 1241519
Click to expand...

There may be some additional connections behind the end shroud. I'd check there first.
 
Pulled the end shroud. For an old motor this thing runs very smooth. Anyways, the picture of the insides below The 4 red wires had stickers numbered 1,2,3,4 left to right in the picture. Two green wires have nothing on them. All six wires go up the inside of the housing to somewhere else. The black wire to the switch connects to the #1 and green wire on the left of the rack. White wire to the switch connects to #4 wire and green wire on the right of the rack.

Sooo, what do I need to do to get this thing running in the other direction?

Thanks in advance.
IMG_2278 (1).jpg
 
You must log in or register to reply here.
Back
Top