how to use vfd for old cnc mill

[jaysihn]

ok, no worries, so i just need to run a wire from fwd&rev down to the contactor or relay and then on the other side of that relay take a wire back to the GND (common) pin of the VFD.

[Jim Dawson]

Yup, that's all there is to it.

[mactec54]

ok, no worries, so i just need to run a wire from fwd&rev down to the contactor or relay and then on the other side of that relay take a wire back to the GND (common) pin of the VFD.

No that is not correct you could not use the contactor to switch this it would be to harsh

And for the wiring the Relay basically is just a switch ( 1 ) side you connect to FWD the other Side to DCM and the same for the Reverse it is best to use a solid state Relay then you won't have any noise with the switching to worry about

[mactec54]

so put 10V output from the VFD to one side of the contactor and then the other side of a contactor back to teh fwd or rev pin of the vfd? I wasn't as comfortable with that just because there are still a variety of other wires going to those contactors that i didn't want to risk screwing up. I figured a couple of DC/DC relays would be safer and cleaner.

Any reason not to use the dc/dc relay option if I want to?

No you should not be using the 10v output from the VFD Drive for anything other than to supply for a PWM to analog Breakout board 0-10v supply

2 Relays is all you need that are controlled by M3 M4

[machinehop5]

so i did some digging to find the wires that correspond to spindle fwd and spindle rev coming from the cnc controller. i found pins 61 and 64 which seem to be 24V logic pins. they go into some relays which have 120V output that feed the main contactors..

...these relays look like Solid State Relays (SSR) already installed from factory. photos worth a thousand words

[Al_The_Man]

...these relays look like Solid State Relays (SSR) already installed from factory. photos worth a thousand words

Opto22 I/O modules, AC output, maybe.
Al.

[machinehop5]

Opto22 I/O modules, AC output, maybe.
Al.

...bingo. I think you nailed it. http://documents.opto22.com/0510_Std...data_sheet.pdf

[jaysihn]

Ya those are ac output. They have 20 something vdc on one side and 120v ac on the other side. I wired it up with the contactors as the switches to pull the fwd and rev pins to the gnd/common of the vfd. Works perfectly at this point...

[Jim Dawson]

Sounds like you're making progress.

[machinehop5]

...its all jaysihn's default for saving the Lagun250....