G540 VFD output not turning completely off

[Aracheon]

In all the searching I've done against the G540 and wiring it to a VFD, it seems that the majority of the problems are with people getting voltage out.

My problem seems to be the opposite... I can't get the G540 to stop outputting voltage when I tell Mach3 to turn the spindle off.



I'm using the G540 in conjunction with a Minarik MM23001C drive which is powering a treadmill motor. According to the spec sheet, the analog input voltage range for the drive (using the 90VDC armature setting) is 0 - 1.4VDC. I'm supplying that voltage to the G540 directly from the drive itself. S1 (-) is wired to pin 7, S2 (signal) is wired to pin 8, and S3 (+) is wired to pin 9. Spindle control is enabled in Mach3, PWM enabled, and once everything is plugged in and turned on, pin 8 is outputting about 0.3VDC when the spindle is turned OFF in Mach3. When I turn the spindle ON in Mach, the motor spins up to full speed and works fine. I have the pulley setup to go from 1 to 5000rpm, and I can control the motor speed from within Mach3 without a problem, other than it won't completely turn off.

Has anyone seen this before? Is there a bit of wiring I overlooked or missed? Why is the G540 outputting voltage over pin 8 when it shouldn't be?

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[Aracheon]

I've tried isolating the power input to pins 7 and 9 by utilizing a CC power supply, which doesn't seem to change the results.

And I just realized I made a typo above. When the spindle is turned on with F5, I'm seeing 1.7VDC between pins 7 and 8 on the G540. When the spindle is turned off, I'm seeing 1.3VDC, not 0.3 at stated in my first post.

When putting the pot back into play, I have 0VDC between S1 (VFD -) and S2 (signal input) on the drive when the pot is turned completely off. I have 1.54VDC at full clockwise.



I'm stumped. It's almost like the G540 isn't functioning correctly. :|

[dmauch]

Here is how to test the G540. Disconnect any wires you have to the +10 terminal (9) and the VFD ground terminal (7). Connect a 9V battery + to terminal ( and the battery - to terminal 7.
Now run mach3 and try MDI using M3 S5000 Then connect a VOM to terminal 8 and 7 and read the voltahe. Then enter in the MDI window M5 and you should read Zero.
Dan

[Aracheon]

Here is how to test the G540. Disconnect any wires you have to the +10 terminal (9) and the VFD ground terminal (7). Connect a 9V battery + to terminal ( and the battery - to terminal 7.
Now run mach3 and try MDI using M3 S5000 Then connect a VOM to terminal 8 and 7 and read the voltahe. Then enter in the MDI window M5 and you should read Zero.
Dan

I will give that a try. Stand by.