VFD stopping

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Downwindtracker2

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A basic question, machinery, in this case a lathe, needs two types of stop, hard and soft. I'm a retired millwright with just basic electrical and computer skills, so please be understanding. I'm wiring up a Hitachi WJ200 VFD . The hard, E-stop seems easy enough to program and wire , there is section on that in the big manual,but the soft has me puzzled. I get the part about run forward and run reverse, pins 1 and 2. Is soft stop automatic with switching off of RUN ? THX
 
Downwindtracker2 said:
Is soft stop automatic with switching off of RUN ?
Click to expand...
Yes, you set that with the deceleration parameter. If your VFD will accept a braking resistor then it will stop the spindle a bit faster if that is installed. Without a braking resistor it may need as much as 5 seconds of decel, maybe 1 or 2 seconds with the braking resistor.
 
I am not an expert but yes the soft stop is adjustable through the programing. It can be changed for how fast or slowly you want.
 
The Hitachi VFD has two selections for braking rate which is Stage 1 (default) or Stage 2 which is selected by an programmed additional input. The default input for 2 stage braking on the WJ200 is input 5, but one can program each input accordingly. The time you set for each input is what you select, stage 1 or stage 2 is not in any specific order. My recommendation is usually to program stage 1 as a faster stop time to something like 1 second (default) and stage 2 to something like 2.5 seconds. Thus stage 2 is active with a front panel switch on the front panel which activates the programmed input. When you press the E-Stop (depending on it's purpose) it interrupts L or P24 (Sink or Source) connection which shuts down the run commands and also the stage 2 if activated, thus a quicker stopping. You do run the risk (in particular w/o an external braking resistor) of tripping a buss over voltage error (and putting the VFD into a free-run) if you try to stop a large chuck/heavy workload too fast spinning at high speed. The WJ200 does have some settings to minimize this.

The WJ200 does not have a program parameter for a fast stop (E-Stop) that is for a specific input, it only has a parameter to prevent the VFD from starting if it has an active run command on power up.
 
Thank you, I really appreciate the help. I've gotten old and slow, both of foot and brain.

So for a longer timed deceleration, I would have to choose a parameter for when power is off to the RUN , forward or reverse ?

Are you saying E-stop will not work with a standard mushroom head when engaged , switch closed?

The inverter is a Hitachi WJ200-015SF , the motor a Baldor TEFC 2hp, lathe a DF1224g. A Taiwanese generic sold by BusyBee. Grizzly also sold it.

I'm getting excited about getting my lathe back and running.
 
VFD is not a power source for the lathe, it is a direct connection between the VFD output and the motor. So no contactors, not overload relays, etc. As such you need a means to tell the VFD what to do which is accomplished with low voltage (24VDC and a few mA) triggered inputs. If you have those hardwired to your spindle switch, then you have no safety (E-Stop , power up, belt cover, etc.) so I do not advise that. On a new lathe it is possible to strip out the high voltage to the contactors and use them to switch the low voltage inputs of the VFD, used contactors doesn't work well because of the increased contact resistance with contacts designed for higher voltage/amperage. Check out the below last posting for some documents which goes through suggestions for connecting the VFD and programming. I have some older VFD designs that use a single 4 pole relay that will work with the WJ200, but requires some basic wiring ability and a few parts.

www.hobby-machinist.com

Pm1340gt Lathe Basic Vfd Control Conversion Using The Stock Control Board And Switches

So I am already up to $700 for VFD and enclosure in my shopping cart, and I am probably forgetting some things. WOW. @mksj shoot me a DM to discuss the possibility of having this built out. I am growing somewhat overwhelmed. I sent you a spreadsheet of my cart. Hey Christian I’m in the same...
www.hobby-machinist.com www.hobby-machinist.com
 
The reason I looked into a VFD, the lathe,a'91, had fried the forward contacts so the previous owner had wired the reverse for forward. Rather than rebuild, it made more sense to add a VFD. And I get variable speed, braking, and jog. 1/2 speed would be nice. I found the motor on Craig's list for $20 and adapted it. I phoned within minutes.1725rpm, 230 volt, 3ph. The mechanical aspects are what millwrights do. While I was at it, I did spindle bearings and belts. For the electrical, I simply pulled the guts out, put them aside, same for the control panel, and added a new box and control panel.

Was I wrong in thinking VFD could supply low power for switches ? off the "L" pin ?
 
Downwindtracker2 said:
Was I wrong in thinking VFD could supply low power for switches ? off the "L" pin ?
Click to expand...
Not at all. But to be used for only for the VFD control. Not sure about the ''L'' pin, don't know what that does.
 
You have to understand when I started this journey, my comment was "It's tough to read a book if you don't speak the language." That was just a couple of weeks back. I was counting on my oldest son , the electrician , to wire and set up. I didn't take into account his wife, so the lathe sat for a couple of years with the main wiring done, but not the control or programming. To be honest, I was more than a little overwhelmed . 30 years ago, it would have been a different story. But.........

I've come to understand sink and source, pot wiring, even Esc. So you see my understanding was pretty elementary .

So when I say your help is appreciated, I really mean it.
 
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