Electric Motor Selection

The big difference is the IP rating. Compressors usually run in a cleaner environment so an ODP (Open frame Drip Proof) motor will do. Since sawing wood is a dusty enterprise I would go with a TEFC (Totally Enclosed Fan Cooled) motor to minimize wear and tear and maintenance intervals, plus it's less likely to spark a wood dust explosion. Just make sure that your circuit can handle the starting current/voltage drop when you flip the switch.

Either motor would work, but neither would be better than a table saw motor which is better for a variable load....

http://www.ebay.com/itm/Craftsman-Belt-drive-Table-saw-motor-820030-Rated-1-5HP-3HP-MAX-EXC-condition-/161761561647

Compressor duty is typically a term I associate with grossly over rated motors. If you look at a 5 hp compressor duty motor and a honest rated 3 HP general purpose motor you will see they have almost identical amp inputs and general specs.

Ron,

Be on the lookout for an old repulsion start/induction run motor. You will be able to saw ironwood without stalling.

Lots of good advice in the thread. Only one thing I can add, and that is the motot enclosure itself. You will want an "enclosed" motor to prevent foreign materials from entering. Most common off the shelf are TEFC(totally enclosed fan cooled). You don't say what the saw is to be used for, so, unless you are going to be using it continually and on a regular basis, I, personally, would base my selection on price.

Compressor Duty might also mean a greater starting torque is available. I'd also go with a TEFC for a 3 HP saw motor. Would assume it's 3 phase at that HP.

Thank you all. The motor is for a 10" cabinet saw. The reason for the question is; the common 3 hp, single phase motor used on saws of this size are purpose built and have typically been made by Baldor and Leeson. They are quite expensive, so that is why I am looking for a less expensive motor. Frame size is not an issue, as I can make a suitable mount adapter.

I used to have a repulsion start induction run motor many years ago. It was only about 1/3 hp, but twice as heavy as a modern motor. IT sure had a lot of torque.