I just bought a Pullmax p5/2 and I’m going to need some help getting it to run. It’s a 3 phase, 420v motor that is not dual voltage I believe. I’m planning on using a vfd for the phase issue but I’m not sure what the best solution is for the motor voltage difference. I have single phase, 220v in my shop. I’ve read that I can use a step up transformer but I’m not sure if that’s the best solution. I might just bite the bullet and have an electrician come figure it out. This could be over my head. Is anyone familiar with all the components in the switch box?
Eeek. Stepping up voltage from 220V to over 400V will be a task. You might see if there is the possibility of swapping the motor. I used to run one on 208V three phase, and that one was direct-wired, so at some point they made one that could do that. A VFD from 1 to 3 phase would be easier when using a similar voltage.
Here's a link to the manual, if you, or anyone else needs it: https://www.trick-tools.com/common/documentation/P5_Manual.pdf
I’m using a vfd on my mill which was pretty easy to setup. I just don’t know what’s involved with a step up transformer. Or can I switch to a single phase motor and skip the vfd? I don’t know if there are any pitfalls to doing it that way?
Technically, you could switch to single phase in the motor swap. The caveat is that single phase motors do not deliver power the same as a three-phase one. The torque is delivered more evenly with a three-phase motor. They are better suited for applications like this that require more consistent force on the metal. Three power pulses, applied in a single rotation, versus one.
And additional benefit of using the VFD is that you can tune the RPM, by changing the frequency. Your P5 is intended to run at 1405rpm, and I am not sure you're gonna find a single phase motor rated at that speed. I cannot say for certain if the KD182 on the motor plate is indicative of the frame size, as 182T is a know motor frame size, but you can measure and check. https://www.regalrexnord.com/produc...JoFbO75SaRsBHNWTq_In1HWfNMIwLzGzgyvY6eHd1XKXa If not, see if your measurements are close enough to any of those to make an adapter.
Before modern electronics made VFDs practical and popular, a rotary phase converter was typically used when 3 phase was needed in a location where only single phase was delivered. Essentially that is a 3 phase generator driven by a single phase motor. You might be able to find one with desired output voltage, though I would not expect it to be cheap.
Might be more cost effective to find a replacement motor. Almost all phase converters and VFD’s will be 1:1 voltage output, and would need to be paired with a buck and boost transformer to increase voltage. Here is probably the only VFD with “voltage doubling”. PT makes fantastic quality products and their support techs are a great help https://www.phasetechnologies.com/products/vfd/residential
Thanks for all the info guys. I guess I will start looking for a new motor. With a new motor and vfd, can I bypass the switch box? Are the components in the box for some sort of thermal overload?
If you get another three-phase motor, and use a VFD, you can use all the existing on-machine wiring as intended. There are new old-stock motors all over eBay. There are even some from the grandchild company of the one that made the original one. You will need to check your dimensions, but here is one as an example: https://www.ebay.com/itm/336198365264
You can mount the VFD adjacent to the power box on the unit. Single phase goes to the VFD, and it outputs three-phase. The Pullmax will have no idea that the VFD is there.
I just got a new motor installed. Had to travel 3 hours one way to get it but for $75 I didn’t want to pass it up. It’s a 3 phase, 3hp dual voltage motor that I don’t think was ever used. I hooked it up to my vfd on the mill and it works. I think I’ll just install a vfd and bypass the box that is on the Pullmax and use the start button on the vfd.
It was a craigslist find. The guy didn't have the capability to test it but for $75 I figured I could take the risk. The best part is that it's a 182 frame so it bolted right in except I had to cut about a 1/2" off of the shaft.
Curt, it sounds like you are set. The VFD should work great. My P5-2 runs off a rotary converter but with a replacement motor doesn't have the two speeds. It was set up with a pedal that allowed single stroke but being able to control the speed would be a plus. Stan Fulton is the go to guy for these machines.
This could be a stupid question but how were the speeds changed from high to low? Was it a switch on the motor? I see no way of doing it on the previous motor?
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