reversible pole receptacle

**neilbourjaily** · Aug 20, 2025, 05:39 PM

I need to be able to reverse a 120v motor. I'm thinking about building a DPDT switched receptacle. Will any knowledgable members care to advise, please?

**BuffaloJohn** · Aug 21, 2025, 03:48 PM

So - you have missing information to answer your question:

1 - is the motor DC or AC?
1dc2 - if the motor is DC and is only 2 wires (not counting the case ground), then look up DPDT reversing switch and you will find many schematics
1dc4 - more complicated, but possible - find the datasheet on the motor (sometimes this information is printed on the motor)
1ac - see #2

2 - if the motor is AC, do you know the motor can be reversed by changing what is on the various wires?
2? - I don't know - you need to find a datasheet on the motor to find this out (sometimes this information is printed on the motor)
2n - some AC motors can't be reversed because there is no way to access the needed connections
2y - now you need to figure out which wires need to be energized in the CW and CCW rotations and design a switch that will do that

hope that helps...

**Hans Pearson** · Aug 23, 2025, 08:03 AM

Some motors can be reversed by turning the housing with the field winding around and having the drive come out the other side of the motor. This all depend on the location of the connections and the compatibility of the covers to the housing.

**Floradawg** · Aug 23, 2025, 08:20 AM

Originally Posted by neilbourjaily

I need to be able to reverse a 120v motor. I'm thinking about building a DPDT switched receptacle. Will any knowledgable members care to advise, please?

What kind of tool, machine, etc., is it? Or if it is just the motor, what did it come out of?

**neilbourjaily** · Aug 23, 2025, 10:46 AM

Originally Posted by Floradawg

What kind of tool, machine, etc., is it? Or if it is just the motor, what did it come out of?

It's a treadmill (s) I intend to modify. It'll probably be either a Matrix 7xi or a Life Fitness CLST. They are both 120v AC. I don't know how accessible the electric guts are, though I may not care about breaking the onboard electronics.. My thought was to build a corded gang box with a reversing switch as well as adjustable speed as I'd be plugging several into the same box. I'd leave them all at a single speed and control the speed with a variable resistor assembly in the gang box is what I'm thinking.
I am grateful for all input.

**BuffaloJohn** · Aug 23, 2025, 03:49 PM

Originally Posted by neilbourjaily

It's a treadmill (s) I intend to modify. It'll probably be either a Matrix 7xi or a Life Fitness CLST. They are both 120v AC. I don't know how accessible the electric guts are, though I may not care about breaking the onboard electronics.. My thought was to build a corded gang box with a reversing switch as well as adjustable speed as I'd be plugging several into the same box. I'd leave them all at a single speed and control the speed with a variable resistor assembly in the gang box is what I'm thinking.
I am grateful for all input.

Hmmmm... Speed control of an AC motor with a resistor - probably not going to work. An AC motor tries to stay synced with the frequency which is why AC motors generally use a VFD (variable frequency drive). A resistor would drop power but not how you would want it to.

**neilbourjaily** · Aug 23, 2025, 05:56 PM

Originally Posted by BuffaloJohn

Hmmmm... Speed control of an AC motor with a resistor - probably not going to work. An AC motor tries to stay synced with the frequency which is why AC motors generally use a VFD (variable frequency drive). A resistor would drop power but not how you would want it to.

Thank you, BuffaloJohn. I will apply myself to the AC motor controllers that can be seen in the electrics sxn.

**Bony** · Aug 24, 2025, 12:41 AM

Originally Posted by neilbourjaily

It's a treadmill (s) I intend to modify. It'll probably be either a Matrix 7xi or a Life Fitness CLST. They are both 120v AC. I don't know how accessible the electric guts are, though I may not care about breaking the onboard electronics.. My thought was to build a corded gang box with a reversing switch as well as adjustable speed as I'd be plugging several into the same box. I'd leave them all at a single speed and control the speed with a variable resistor assembly in the gang box is what I'm thinking.
I am grateful for all input.

Treadmill motors are usually DC for easy electronic speed control.

I suggest you seek advice from an electrician before attempting to reverse the motor. In my view it will be money well spent, and save you burning the motor out, getting a huge shock or blowing a fuse, or at worse save you from all 3 failures.

**tonyfoale** · Aug 24, 2025, 02:46 AM

Originally Posted by Bony

Treadmill motors are usually DC for easy electronic speed control.

They are also usually permanent magnet types in which case direction reversal is easy. Just reverse the two wires. That is all. However, unless you feed it from a controller or other variable voltage source you will only have a single speed available.

**neilbourjaily** · Aug 24, 2025, 07:12 AM

I'll see the motors on Tuesday when I arrange to get the treadmills. They are also on the second story and may require some degree of disassembly to get them to the ground floor and out the door. I'm getting them from a commercial gym that is rotating out their old treadmills and getting new ones. In my inspection of them, I'll look at the plate on the motor. My intention is to gang them together, charge them through a single gang box, and control them from the box. I want to be able to reverse them and to control their rate of speed.
I thank you each and all again for your insights here. What a fine group to be part of.