VFD questions

[chrispy]

Hi all,

Just picked up a cheap (at least I think so) VFD. I am looking at the Campbell card to control the VFD.

From what little I know about VFDs the interfaces all should be the same. Correct me if I am wrong. In other words, I should have no problem running the Campbell board to most newer VFDs???

Any cheap ways to calibrate the thing? I have heard that they can be relied upon without the calibration. Is this true? If not any cheap ideas how to check? No I have no access to a laser tach.

Thanks in advance,

Chris

For reference,

VFD I won:
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7541241180

Bob Campbell VFD controller
http://www.campbelldesigns.com/mach2...ed-control.php

[Al_The_Man]

That unit was probabally well in excess of $1k, fortunately it has the manual, you will need it!
You will have to scale the command signal to the resultant frequency output, either in the control software or in the VFD parameters, Firstly, do you have a 4 pole motor? if so do you want to run it at 2x speed? (120hz)
To calibrate it, set the mechanical ratio to 1:1 set a speed in the software at the rated rpm of the motor, and then scale the s/w or VFD so that the frequency out is 60hz. The motor will then track the frequency above and below the normal operating Hz.
Any other mechanical ratio and you will have to calculate accordingly.
Al.

[chrispy]

Al,
As always thanks a million. All good advice.

Yes it is a 4-pole motor (spins at 1710). So I should be all set there. At least I hope it is.

You are correct on the manual. I did find the PDF version of the manual before I bid. Took a while as it was hard to find. It is a complicated device. Heck it probably has more MIPs than the original BOSS 3 controls had. I am thinking I will have to set it once and be done with it. Due to the size it will have to go in the cabinet. I do wish the user panel would be detachable, that would of been cool.

I just confirmed with Bob Campbell that it will indeed work as I assumed. Always a quick response from Bob. So I will be ordering the board from him soon. Might as well get the relay card as well, as I cannot find optoisolaters at Radio Shack (do they carry anything any more?).

Thanks for the help on the calibration. Not sure I fully understand what you mean, but after I think about it for a while, I am sure it will be clear.

5hp is a little over rated, but might prove useful later on. Who knows? Really $1k. I had a felling that they were up there. Gotta love ebay.

Thanks again,
Chris