3P/VFD or DC motor

[Bamban]

Just about any 3 phase AC motor would work, especially with a decent VFD running vectorless CT. Decent 3 phase 2 HP inverter rated motors are plentiful, and probably a much easier retrofit then a treadmill DC motor in this size range.

I give up, could you please explain in layman's term what does it mean when you say "VFD running vectorless CT." Is vectorless defined by the design of the VFD or how it is programmed?

 

[mksj]

Running vectorless CT is programmed by the VFD, it operates on any 3 phase AC motor. It essentially is like having an encoder feeding back information to the VFD about what the motor is doing, so the VFD can adjust it's drive parameters. It allows significant more torque at lower speeds. The is a significant difference between in delivery of power between a single phase and 3 phase motor, and one run off a VFD. I can run my 2 HP VFD lathe at very low RPM and it is unstoppable with gloves on the chuck. It really comes down to either choice will work, and provide more than you will probably ever need as to power delivery.

 

[amuller]

I'll just add one more little fact to UD's discussion.

Controllers for 3 phase motors, or VFDs , are quite sophisticated with tons of high end options.

Without going to a major expense, the same things just aren't around for DC motors.

Karl

That has been my experience. DC drives aren't cheap and don't have the features and performance of VFDs for similar pricing. This is not to say you can't do a very nice job with a DC motor. I suspect the future of "DC" motors is in electronically commutated motors, which may well push induction motors aside for many purposes. But for right now it's hard to beat a VFD and 3 phase induction motor.

 

[Jim Nunn]

DC drives

Low cost drive (mostly analog) Technology has not changed in these in the last 30 years.
High cost motors which demand maintenance.
PM motors cannot be ran at higher than motor base speed.
Can produce more starting torque When used with High performance Drive . the Typical Minarik/Dart control is not high performance.

AC drives

Higher cost drive, lower cost motors
Greater speed range when used with Sensorless vector drive (SV) (Most decent drives are SV type). Industrial AC motors can be operated at 1.5 to 2 times the motors rated speed in a constant HP mode
wide range of drive control interface. such as analog output for speed display, E-stop, multiple preset speeds.
Can be easily integrated in a CNC system for spindle speed control
I have both AC and DC drives and I will go with the VFD every time.

Jim Nunn

 

[Bamban]

It has been settled, I went with 3P/VFD route. Well, I said "I" it should have been "We." With the generosity and kindness of
mksj, who provided the kind of help, even from long distance, well beyond anyone's imagination and could only dream of, the system is all wired up waiting for the electrician to show up and wire the 220V. Maybe I should just wire the 220 from the panel to the machine

Stay tuned for the complete write up.