Lenze VFD, how to add forward/reverse switch?

I have a Lenze VFD which I have fitted to a friends Colchester Student lathe to run its 3hp three phase motor using single phase input.

At present I have a remote on/off switch connected between terminals 28 and 20 to start and stop the lathe.


Reversing the lathe spindle direction was originally done by reversing the motor.

I am guessing I can now do this internally in the VFD?

Could I wire in a forward-reverse/off switch? If so, could someone please advise which terminals to connect.

I am electrically challenged but can do basic wiring if it is explained. I can also find my way around the parameter menu if required.

Another question - I guess the motor should be allowed to stop before reversing its direction? Can this be controlled by the ramp times or some other method? Or simply pause between switching direction.

Please see attached diagrams.

Model details:

ESMD222W2SFA000XXID20
Input: 1(2)/N/PE, 230/240 volts, 21 Amps
Output: 3/PE, 0-230 volts, 9.5 amps.
2.2kW (3 hp)
0-240 Hz.
CAN open, Basic I/O
Integral filter

(This model was intended to be controlled by a PLC, but works fine as a single to three phase convertor with soft starts. I can't connect a pot for speed control, but can connect a push button to increase or lower speed. I am not intending to do this at present, it will run at a constant 50 Hz).

BTW, New Zealand uses 50 Hz, 230 volt single phase.

A wire from terminal 20 to a simple on/ off toggle switch and then back to terminal E2 is the FWD REV function.
Closed switch contacts (on) is voltage high, Open switch contacts (off) is voltage low.

Wiring to the MOTOR will determine rotation direction.

Vis. What does Forward mean to a reversible electric motor? "Alternate direction" is a term more meaningful.

CalG said:

Vis. What does Forward mean to a reversible electric motor? "Alternate direction" is a term more meaningful.

Click to expand...

It DOES have an agreed meaning in the three phase world, even so.

eta

Reversing "on the fly" is not an issue. BUT The drive may fault with an over capacity error depending on many variables.

I have VFD's on a a couple different lathes with the fwd/rev control through the apron lever switch gear.
I frequently reverse rotation with a simple flip of the apron lever. High spindle speeds and heavy work pieces sometimes fault the drive. OH! That's hard on carbide!

ps. I've got the ramp up and down set to 3 seconds or so. If I'm doing something where "instant reversing" is an advantage, I set the ramp to .2 seconds, but control the spindle inertia by means of rpm.

ps

I've got a LENZE unit on the shelf behind the MAZAK. I used to use it to run the suds pump.

But that changed, and I've taken it out of service.

CalG,

Thanks very much for your reply, I can now see how to do this with 2 x switches i.e. one switch for on/off and a second switch for fwd/rev.

That's fine and probably what I will do.


Is it possible to do it all of the above with 1 x (three-position?) switch? So FWD - OFF - REV? If so, how to wire?

I am guessing your apron control is doing this?


Regarding "reversing on the fly", I was recently doing this on my Bridgeport when power tapping i.e. switching direction without any pause. After tapping about 20 holes, the motor tripped out and it had got quite hot. After leaving it for a while, it was OK.

This was the original 3 phase motor running direct-on-line 3 phase power, no inverter or anything else involved.

Hence my concern about this. The lathes I use have fwd/rev clutches, so don't mind rapid reverse when screw cutting.

I know from past experience with conveyors that 3 phase motors don't mind being switched on and off every few seconds, all day, every day. But since my Bridgeport experience, I'm not so sure about (repeated) rapid reversal of a motor running at 50Hz.

This should pretty well cover what you're looking to do with the Lenze VFD.

Lenze SMV Training Lesson 5: Basic Start Stop Selector Switch Control Wiring & Programming - VFDs - YouTube