spindle start/stop through VFD

[endgrainguy]

I"m going to be running a high frequency spindle on a CNC machine with this VFD :Hitachi SJ200-015NFU. Will I be able to start and stop the spindle with a simple relay, (this one:http://www.cnc4pc.com/Store/osc/prod...roducts_id=132) as I've been doing with simple 110 volt router, which will essentially cut and open the 220 volt single phase power into the drive, or do i need to do something more sophisticated than that? And if so, what? I"m happy enough with manual speed control via the VFD keyboard, but I want g-code starting and stopping of the spindle. In other words, will the drive remain in a "restartable" state ,via the relay, after power into it is cut ?
Thanks! Al Ladd , Colrain MA

[orbyog]

It is not a good idea to control via disconnecting input power to the VFD, Manual states "This will reduce the operating life cycle of the AC drive" as well you will loose the braking power of the drive. You should connect the relay to the control input as explained in the manual ( http://www.hitachi-america.us/suppor...ok_NB650XA.pdf ). Also the relay you mentioned is for A/C only, you will need a C9 or some other DC relay ( I used optoisolators in my case).
Robert

[Al_The_Man]

Opening the feed to the drive is not only undesirable it defeats the whole object of VFD control.
You will not get the advantage of controlled deceleration start/stop etc.
There are configurable low voltage inputs to control start/stop/direction etc, also variable speed or programmable pre-set speed settings.
If you want CNC S & M3/M4/M5 control then you will need power at all times to the drive.
Al.

[Greolt]

I use the same VFD to drive a 1.5 hp Chinese spindle.

The others are of course correct. A simple on off via gcode is done via one input on the VFD.

But why not do it properly and have the gcode also control the rpm?

Look at Peter Homman's Digispeed, this is the one I use,

http://homanndesigns.com/store/index...products_id=39

It will provide the 0 - 10 v speed control from a step signal, as well as having two on board relays for stop start, forward and reverse if wanted.

I get a nice linear speed ramp. Using Mach3.

Greg

[TOTALLYRC]

Originally Posted by endgrainguy I"m going to be running a high frequency spindle on a CNC machine with this VFD :Hitachi SJ200-015NFU. Will I be able to start and stop the spindle with a simple relay, (this one:http://www.cnc4pc.com/Store/osc/prod...roducts_id=132) as I've been doing with simple 110 volt router, which will essentially cut and open the 220 volt single phase power into the drive, or do i need to do something more sophisticated than that? And if so, what? I"m happy enough with manual speed control via the VFD keyboard, but I want g-code starting and stopping of the spindle. In other words, will the drive remain in a "restartable" state ,via the relay, after power into it is cut ? Thanks! Al Ladd , Colrain MA

I am using the 3hp version of that drive and it is real nice to turn it on and off from the gcode. Once you also set it up to do the s commands from mach3, you will wonder how you ever did without it.

Once you get the rpm figured out for a particular job and then save it to the code, every time you run it your speed will be correct. You won't start of at the wrong speed and break something.

Mike

[endgrainguy]

OK, looks like the way to go. This is the functional equivilent of the Hoffmann Aussie board right? http://www.cnc4pc.com/Store/osc/prod...products_id=58 And the input to the VFD is going through this board, and configued in MACH as if it were an axis motor? (CNC4PC gives decent intructions on this, if I'm understmading them correctly). If you guys with the same or similar Hitachi drives could clue me in on the correct terminals and their configurations for this purpose it'd save me some considerable hair tearing! Thanks, Al Ladd www.alladd.com