Powermatic 1150a Motor Swap

[Dimitrios Fradelakis]

I will be picking up a Powermatic 1150a drill press on Monday but the problem is that it has a 3 phase motor. I, like many others, do not have 3 phase power in my home. I was contemplating between buying a rotary converter and swapping the motor out to a 1 phase. I came across a Powermatic 2800b single phase motor and wanted to know if it would be a direct swap. I would rather go this route seeing as it's a single phase plus it's 1 HP and the 3 phase motor is 3/4 hp. If this motor isn't a direct swap, can anyone recommend a motor that is? Thank you for your help.

[Bob Vaughan]

The 1150A uses a plain vanilla NEMA 56 frame TEFC motor. The factory HP rating was 3/4 which is plenty adequate.
The 2800B is a shiny from China machine. The specs don't say whether its a USA 56 frame or a metric dimension frame motor.
If your existing motor is a 220/440 volt motor consider a VFD. That will allow you to dial down the motor speed to a crawl because the lowest speed for a standard 1150A is 475 rpm with a 1750 RPM motor. A one HP rated VFD can be had that uses 110 volt household current.

Gotcha details: If your motor is 200 or 208 volt only, talk to the VFD sellers about compatibility.

[Dimitrios Fradelakis]

The 1150A uses a plain vanilla NEMA 56 frame TEFC motor. The factory HP rating was 3/4 which is plenty adequate. The 2800B is a shiny from China machine. The specs don't say whether its a USA 56 frame or a metric dimension frame motor. If your existing motor is a 220/440 volt motor consider a VFD. That will allow you to dial down the motor speed to a crawl because the lowest speed for a standard 1150A is 475 rpm with a 1750 RPM motor. A one HP rated VFD can be had that uses 110 volt household current. Gotcha details: If your motor is 200 or 208 volt only, talk to the VFD sellers about compatibility.

Bob, thank you very much for your detailed response. Much appreciated, sir!

[Bob Vaughan]

About a year ago I did a motor swap-out on an 1150A and used a "Farm Duty" Leeson 56 frame motor I had. A direct bolt-up. The mag starter had to be slightly modified to take the lower current (change coil and heaters). I liked the crank-up table on this one and I already had other drill presses that will go down to zero, so I went for the direct motor swap.

[Dimitrios Fradelakis]

Thank you for the photos and response. If I stick with 220v I don't need to modify the magnetic starter, correct? My 220v outlet will be a few feet away from the drill press so making the motor run off 110v is not an issue to me. Also what is size is the shaft? I assume 5/8?

[Bob Vaughan]

220v will work fine then. I have no idea what kind of switch (starter) you have, but usually one of the 3-phase legs is simply ignored. Powermatic used several brands and types of starters over the years for those presses.

NEMA frame dimensions

[Dimitrios Fradelakis]

Thanks, Bob!

It's a standard 5/8 shaft, right?

[Bob Vaughan]

Yes, the shaft size of a standard NEMA 56 frame motor is 5/8".

[Dimitrios Fradelakis]

Thank you for all your help!