VFD or DC

[SBLCHET]

I have a SBL heavy 10L (1976) and want to put an adjustable speed motor system into it.
Have some questions about VFD or DC motor with adjustable speed and reversing.

1. What is the average cost to set up a VFD system if you have the 3-phase motor?

2. Would the VFD have a full range speeds and be totally reversible?

3. Is the VFD as quiet as DC motor at all speeds?

4. Why do most people choose VFD over DC?

5. If given a choice with no cost differents, which would you, choose VFD or DC and why?

Thanks Chet

 

[Amigo]

Chet, IIRC, I read somewhere that some AC motors are wound in such a way as to be incompatible with a VFD and are very short lived if used with one.
I'm sorry I don't remember the source, But you might research the subject a little further to ensure a VFD is used with a compatibly wound motor.
While I'm thinking about it, with RPC's, a Delta wound 3 ph. is superior to a "Y" aka "star" wound motor.

 

[SBLCHET]

I came down with the Flu and just got back to reading my post. Wow a whole lot of info. Going to set back and read all the replys.
Thanks to everybody Chet
I will be getting back on which way I deciede to go VFD or DC.

 

[SBLCHET]

Well I should not of said I had the Flu should of said I caught a cold and wasn't feel well for the past couple of days.
Chet

 

[pdentrem]

Chet, IIRC, I read somewhere that some AC motors are wound in such a way as to be incompatible with a VFD and are very short lived if used with one.
I'm sorry I don't remember the source, But you might research the subject a little further to ensure a VFD is used with a compatibly wound motor.
While I'm thinking about it, with RPC's, a Delta wound 3 ph. is superior to a "Y" aka "star" wound motor.

Here is a link to a pdf about inverters and motors.

http://www1.eere.energy.gov/industry/bestpractices/pdfs/motor_tip_sheet14.pdf

I clipped this from one of the multiple motor sites.

*Inverter Duty Motors - Initially standard AC motors were employed on inverter drives. Most motor manufacturers
now offer Inverter Duty Motors which provide improved performance and reliability when used in Variable Frequency
Applications. These special motors have insulation designed to withstand the steep-wave-front voltage impressed by
the VFD waveform, and are redesigned to run smoother and cooler on inverter power supplies.