Moore #1 Motor Help

[unixgeek]

Hello,
I'll start off by saying that I'm very new to machine tools. I just picked up a Moore #1 Jig Borer to replace my benchtop Enco mill. The Moore came equipped for 440V and I'd like to remedy that. I figured the path of least resistance is to replace the motor with something in 230V single or 3-phase and run a VFD. I pulled off the old motor and found that the mounting face seems sort of unique (at least not something I've seen before). I'm wondering if anyone can give any insight into what case style this motor is. Or maybe I'm barking up the wrong tree searching for a replacement and should modify this motor.

Here are some pictures:







Thanks!

 

[Wireaddict]

Howdy, it doesn't appear the company that made this motor is still active but Moore Precision Tool is. The ID tag on the motor doesn't show a frame size so you can't shop around for a match. You might contact Moore to see if they have a 240V motor in either single or 3-phase. Your last &, probably most expensive choice is to have a motor shop rewind this motor for 240V, 3-phase but they usually charge more than the cost of a new motor.

Dave

 

[rdhem2]

Mr. Wireaddict is right on track. Not much to add but the strange to you mounting is called a "C" face mount. In the absence of a frame number the Type number may be a lead but other then that 240 3 ph is the way to go.

Also the motor speeds are a little odd from todays designs.

Maybe a sharp rewind guy could take a look and find the splices in the windings and convert this one without having to rewind the whole thing. Sometimes the splices are visible sometimes not.

Good luck, hate to see old iron go to waste!


Edit note: On second thought that is probably why this is a straight voltage motor. With two speeds and the high pole count that is a lot of wire to get into that small a stator. Let alone doubling it to get two voltages!

 

[unixgeek]

Face mount motors aren't unfamiliar to me. It's the spacing of the mounting holes that seems weird. All of the c face-mount motors I've seen have mounting hole spacing of 90-degrees. Is this common?

 

[strantor]

That's an odd duck alright. Works out to 6pole/12pole configuration. I doubt anybody sells or knows how to build one. And what's up with that bolt hole pattern? Sheesh. I'd look for an 8 pole c-face motor of similar dimensions and shaft dimensions, drill and tap the correct bolt pattern, and run it on a VFD up to 80hz to get the original correct RPM out of it. Running an 8 pole motor at 80hz is going to be more efficient than running a 4 pole motor at 40hz. This is assuming to can't find a 6 pole motor in the correct dimensions, which you may very well be able to find, and if you can, that would be optimal. 4 pole and 8 pole are more common in my experience.

 

[unixgeek]

Well, I looked and looked for a suitable motor. I decided to take a well-traveled path instead. I used a transformer to get 480V 1ph and used a AD 1305 to drive the motor's higher speed.

I got it running yesterday and, so far, haven't had any problems.

 

[Wireaddict]

I think you did the right thing; I had to do the same thing with my Sheldon lathe. I found out after I bought it that the motor is straight 480V, 3-phase. I made the mistake of assuming that the motor was dual voltage until I got it in my garage & opened the pot head & found only 3 wires [the motor didn't have a name plate but was running on 480V where I bought it]. Back to your situation, isn't your motor 3-phase? So didn't you get a 240-480V, 3-phase step-up transformer? [I had to get a 6 KVA unit for my lathe to make sure it was big enough since I didn't know the full load current.]

 

[unixgeek]

I think you did the right thing; I had to do the same thing with my Sheldon lathe. I found out after I bought it that the motor is straight 480V, 3-phase. I made the mistake of assuming that the motor was dual voltage until I got it in my garage & opened the pot head & found only 3 wires [the motor didn't have a name plate but was running on 480V where I bought it]. Back to your situation, isn't your motor 3-phase? So didn't you get a 240-480V, 3-phase step-up transformer? [I had to get a 6 KVA unit for my lathe to make sure it was big enough since I didn't know the full load current.]

I got a 1-phase 5KVA step down transformer, wired it with the secondary as the primary to get 460V 1-phase out. Then run that into a AB 1305 connecting the two hots to L1 and L2 in. I've read that if you run the VFD this way, it needs to be rated for at least 2x your motor's HP. My motor is 0.5HP so I got a 2HP (yes, 4x) VFD. The VFD converts the AC to DC and then back to AC at whatever frequency is requested. So the missing legs on the input isn't a big deal. Some VFDs fault on missing input legs, but not the AB 1305.

 

[rdhem2]

WOW!!!

An Allan Bradley drive with no inherent phase failure function! Very interesting.