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Re: Anomalous Behavior of Beagle Bone Green on Acorn Board with separate power supplies
Posted: Mon Feb 05, 2018 3:16 pm
by martyscncgarage
andyolney wrote: ↑Mon Feb 05, 2018 2:47 pm
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
Its buried in all the messages...try and search for VFD or TECO VFD
Did you disconnect the wire from the VFD to Acorn com and the outputs, I assume Acorn starts ok then?
Is there a manual in PDF format you can post for your VFD?
Re: Anomalous Behavior of Beagle Bone Green on Acorn Board with separate power supplies
Posted: Mon Feb 05, 2018 5:37 pm
by andyolney
Yes, Acorn starts with both power off to the VFD and the terminals 4 and 5 disconnected.
Attached is the manual, looks like a relevant bit might be this:
Thanks for the help.
Andy
Re: Anomalous Behavior of Beagle Bone Green on Acorn Board with separate power supplies
Posted: Tue Feb 06, 2018 10:02 am
by martyscncgarage
andyolney wrote: ↑Mon Feb 05, 2018 5:37 pm
Yes, Acorn starts with both power off to the VFD and the terminals 4 and 5 disconnected.
Attached is the manual, looks like a relevant bit might be this:
clip.JPG
Thanks for the help.
Andy
Did you measure for DC voltage between COM and FWD?
with the VFD wires disconnected from Acorn
It appears to be that COM is at 0 potential an theoretically should be able to be connected to Acorn COM.
Perhaps Matt Centroid Engineer can take a look.
Marty
Re: Anomalous Behavior of Beagle Bone Green on Acorn Board with separate power supplies
Posted: Tue Feb 06, 2018 3:41 pm
by andyolney
I have the common tied together on both the acorn and the vfd, including the 0 to 10 volt speed control.
The voltage between the common and the forward terminal is about 23 volts.
Andy
Re: Anomalous Behavior of Beagle Bone Green on Acorn Board with separate power supplies
Posted: Wed Feb 07, 2018 10:33 am
by eng199
Voltage from the VFD input is feeding back into the ACORN output before the ACORN supply starts.
Review the document on the first page of this thread or the sticky post here:
viewtopic.php?f=60&t=1470&sid=d4d62d288 ... ae6df2aea5