Centroid Community CNC Support Forum

Well done Keith. Thanks

Follow up on this issue.
I have been having an intermittent failure to turn on but don't quite fit the profile since I have one of those Leadwell dual PS. Following a hint on the Hobby Machinist BB, I removed power from my VFC before turning on the Acorn and got it to boot. Looks like anything connected to the acorn has the potential to cause this behavior.
Andy

andyolney wrote: ↑Sun Feb 04, 2018 4:42 pm Follow up on this issue.
I have been having an intermittent failure to turn on but don't quite fit the profile since I have one of those Leadwell dual PS. Following a hint on the Hobby Machinist BB, I removed power from my VFC before turning on the Acorn and got it to boot. Looks like anything connected to the acorn has the potential to cause this behavior.
Andy

What model VFD are you using?
If you completely disconnected the VFD does it come up consistently? Is it easy enough to reinstall and test the axis motors?

It's a 20 year old Boston Gear /Fincor / Ace KL inverter.
Just tried to start with the inverter on had a failure, turned the vfd off and was able to start fine.
Axis motors are working and don't seem to affect the startup.
Andy

andyolney wrote: ↑Sun Feb 04, 2018 5:42 pm It's a 20 year old Boston Gear /Fincor / Ace KL inverter.
Just tried to start with the inverter on had a failure, turned the vfd off and was able to start fine.
Axis motors are working and don't seem to affect the startup.
Andy

I'm curious to know if the VFD itself is causing the issues. Does it have a common for FWD/REV reset or does it supply voltage? A screen shot of the wiring diagram from the VFD manual would be helpful....I guess I wonder if it would be worth your while to test with another VFD?

It supplies voltage, I am seeing about 23 v, and the acorn output pulls it low.

At the moment, am going to make it part of my startup to turn on the VFD last.

Actually made my first part for my lathe conversion last night, a cover plate for the the x axis motor mount, the simplest part I could think of.

Andy

andyolney wrote: ↑Sun Feb 04, 2018 8:10 pm It supplies voltage, I am seeing about 23 v, and the acorn output pulls it low.

At the moment, am going to make it part of my startup to turn on the VFD last.

Actually made my first part for my lathe conversion last night, a cover plate for the the x axis motor mount, the simplest part I could think of.

Andy

If it supplies voltage you shouldn't be able to use it that way....some guys that have VFDs that use 24vdc to activate it's own inputs had to use small relays. You are taking VFD to Aforn common which is at 0 at the Acorn Power Supply.

Do you have a wiring diagram out of the VFD manual you can post?

Marty -
Your are right, after looking at the Centroid output schematic, I think I am seeing the voltage from the Acorn not the VFD. I have the thing programmed for 2 wire control. Terminal 3 is ground, top diagram. No good schematic in the vfd manual.

Andy

andyolney wrote: ↑Sun Feb 04, 2018 11:58 pm Marty -
Your are right, after looking at the Centroid output schematic, I think I am seeing the voltage from the Acorn not the VFD. I have the thing programmed for 2 wire control. Terminal 3 is ground, top diagram. No good schematic in the vfd manual.

Andy
IMG_20180204_192755.jpg

You should temporarily disconnect the Acorn outputs from the VFD, and measure between your VFD common (terminal 3)and its fwd terminal to see what you read. I'm wondering if it's 24vdc.

Marty-

Ouch, wrong again! Somehow I got the diode direction wrong in my head in the Acorn output schematic.

The vfd does indeed have a positive voltage (about 23v) at terminals 4 and 5 when I disconnected from the acorn.

On the other hand, the acorn seems to control it fine: CW, CCW, and speed control work. Can you point me to the thread where this is discussed ?
I do have a relay board I can use if needed.

I tested the acorn turn on again - no lights or heartbeat if the VFD is on before I power the acorn.

Andy