Centroid Community CNC Support Forum

I have recently installed the ACORN CNC on a CT054 BusyBee Mill and am using a LENZE VFD for my 3 phase motor (upgrade). Unfortunately the generic VFD wiring diagrams do not fully work beccause they do not allow the VFD to turn off the motor because LENZE has a safety circuit and funny off switch so to speak. It must recieve a signal off. Since ACORN lacks DPDT relays on there relay board I have added to relays that are driven by the ACORN generic circuit which in turn switch the LENZE VFD taking advantage of both systems (no programming changes on the ACORN side.

When I have time I will post a drawing for those interested.

Speed control through the H8 connectors works well and attached to 2 (0-10VDC Com) and 5 (0-10VDC) on the LENZE Terminal Strip.

You should post a link to the manual for this inverter

Ac lenze drive are very good, i love mine. My guess is you are not setting Parameter P120, 121, 122, 123 correctly which controls how the start stop direction circuit works. 13 a b and c terminals on the drive are programable how they act by the previously mentioned parameters. And you do have your relay outputs to 1, 4, 13a, and 13b on the drive right?

See pages 33 and 34 of the ac lenze drive manual.
https://inverterdrive.com/file/Lenze-AC-Tech-SMV-Manual

My manual is a little different

https://download.lenze.com/TD/ESV__SMV% ... -0__EN.pdf (this is the newest one).

Setting on mine include P100, P101, P112, P121, P123, P160, P161

Mine is wired as per drawing 2.1.2 setting page 67 (or 69 on pdf viewer) more or less.

No start button.
Stop is part of the circuit.
Speed pot is I believe 2 and 5 only directly to analog speed control

The Acorn relay outputs are wired to the relays (mine) in series on the coils to drive the required outputs on the VFD. One relay for FWD, one for REV.
This issue with Lenze is that it requires a dedicated stop. Spindle reset does not do this unless Emergency stop is pressed on the Acorn, regular rest does not. So the solution is a relay (for each direction) that has 2 NO/NC contacts (vs 1 on Acorn) is required and a little fancy wiring is required to send the correct signal to the VFD.

The advantage to doing this is that no special programming is required on ACORN and No special programming is required on the VFD. Fail safe condition shuts spindle down.

You are correct that revised "my" relay outputs drive 1,4, 13A and 13 C and Acorn relay output drives my relays.

I'll create a drawing that will give the correct wiring diagram for change.