Converting a 3 ph powermatic TS to single phase

[Dean Chapel]

I see a LOT of used powermatic table saws that are 3 phase for sale. How much is the most you would pay for a 3 phase say knowing you will have to convert it to single phase? What would be the best single phase motor to switch to? Any info appreciated.

Dean

[Thomas Hotchkin]

Dean
If the 3 phase motor on the saw is in good shape, look into a VFD for about $200.00 you can use the starter that is on the saw now. There is a lot of good info on VFD on the Creek. Might save you some money in the long run. Tom

[Mark Ashmeade]

I have a PM72 with a 7.5hp 3ph beast on it. No way I'm switching it out. I'll build a RPC for about $400 and off we go resawing railway ties!

RPC the way to go, or VFD for smaller motors. Cheaper and better.

[Rod Sheridan]

Hi Dean, I would add the cost of purchasing a VFD (Variable frequency Drive) to the saw cost and see if that's reasonable.

As a guess, I would take 50% of the replacement cost, so for a $3,000 dollar saw I would pay a total of $1,500 maximum.

If the the VFD is $200, then that leaves me with $1,300 for the saw..................Regards, Rod.

[David Kumm]

Used saws are such a good deal now that you can often find a PM 72 or a Delta/ Rockwell 12-14 more little more than the 66 or unisaw. If the saw has a magnetic starter as most larger saws do you will have to bypass the existing unit if you go the vfd route. However you do it, keeping the three phase motor is preferable. check the after market riving knife systems and you are golden. Dave

[John McClanahan]

If the PM66 has a 3 HP motor, a VFD would be a good choice. I bought one with a 5 HP motor. In order to run the 5 HP motor at full power, I would need to get a 7.5 HP VFD, to overcome 1 PH to 3 PH current de-rating. I don't have enough shop power to supply the big VFD, so I changed out the motor.

John

[Rod Sheridan]

If the saw has a 5 HP motor, buy a 3 HP VFD and program it for 3 HP......................Regards, Rod

[John McClanahan]

I came close to going the 3 HP VFD route, but I had the extra Baldor motor lying around so I built a motor mount adapter and used it. I'm happy with my current setup, but if I ever get to wishing for more power, I still have the 5 HP motor.

John

[Don Jarvie]

It may be easier to swap the motor. I found a AO Smith 3hp that fits the PM 66 for 200.00 on the bay. I swaped out the starter for another 75 and needed 2 new pulleys. 300.00 total.

Only issue with the AO Smith is the motor has no reset so you need a NEMA 1 starter with overload protection. If the motor has a reset you can use a starter without overlaod which may be a bit cheaper.

Looking at the VFD and RPC costs it was the the same for the VFD and less than the RPC.

Don

[keith jensen]

When pricing out the VFD option, make sure you take into account the cost of an enclosure (assuming you buy a lower end IP20 verus a NEMA 12 or 4) and plugs/wiring for it. That stuff adds up pretty fast. I decided to make mine portable which required extra strain reliefs for the cables as well.

Looking back at it, I probably could have spent $300 changing out the motor and starter and pretty much broken even with the VFD. For me, it's not so much about breaking even as it is about learning new things though I guess.