VFD Reset Output No Working

[MecTechMike]

Folks,

Running the mill, I programmed a output relay to get a VFD reset signal to pull the VFD out of reset.  I know its just supposed to pulse the relay after clearing an E-stop, but I don't observe it working at all. Might I be missing a configuration issue? Running 4.20 on a Rev 4 board (relay board rev 1.1).

Thanks,
Mike

[carbuthn]

Mike,
What model / brand of VFD are you using?

I am using a GS2 on the Techno lathe and the reset appears to work correctly as wire in the pages that I attached. Of the VFDs that I have looked at, they have had a parameter for external reset.
Chuck

Acorn - VFD Settings.pdf

(124.27 KiB) Downloaded 142 times

[MecTechMike]

Thanks Chuck,

I have the same drive. Love it. The issue is on the Acorn side. I see/hear no evidence that the VFD Reset relay activates.

Mike

[carbuthn]

I will recheck mine tomorrow.

[cnckeith]

post a fresh report.zip....

[Richards]

The manual shows three steps.

1. The fault must be cleared for the drive to reset
2. Parameter P3.02 must be set to 02 to enable an external reset
3. DI3 must be pulled low to reset the drive

I would check/change parameter P3.02 to verify that it is 02.
I would connect DCM to Acorn's GROUND.
I would connect a relay common to Acorn's GROUND and its N/O contact to DI3, then, when the relay activates, it sinks current through DI3.

(My GS1 is sitting in a box, waiting for me to build a lathe around it, so I can't test anything, assuming that the GS1 and the GS2 have similar external reset circuits.)

[carbuthn]

Mike,
I am setup that way except I have not tied the DCM and Acorn grounds together. The three relay commons tie to the DCM only (only because it is shown that way in the manual). I originally was using the Acorn common, but changed to the DCM connection.

I did have to tie the commons from the Acorn and the PLC together to get them to play together. May need to tie the VFD, PLC and Acorn together.
Chuck

[Richards]

Typically, all grounds are tied together. Ground is the reference point from which all voltages are measured. Common practice also ties earth ground to signal ground, i.e., the earth ground and signal ground are common on the Acorn board. I have build controllers for other machines that used opto-isolators to separate my system from other systems in other buildings that each had their own ground rod driven into the ground at the service entrance to each building. I haven't run into that type of situation in several decades. Now the only connection between buildings is fiber internet cable, not the copper cable that we used at that time.

When I build a system, I use a bank of terminal blocks for ground (earth and signal). That bank of terminal blocks is also tied directly to a bolt in the metal enclosure so that the enclosure and the two types of grounds are tied together. On the test bench, I do things a little different. Typically, I mount components for each subsection on a 6"X18" piece of sheet steel from Home Depot. Each subsection has it's own set of terminal blocks. I tie the grounds between the steel subsections together so that all metal is grounded together. In reality, that is a daisy-chain, but each subsection has a 14-awg wire connecting it to the next subsection. The distance is short. That daisy-chain works on the test bench, but it is not an approved practice.

We sometimes think of a relay the same way that we would think of an external switch. On the GS2, if a switch were inserted between DCM and DI3, when the switch was closed, the circuit would be closed. We could connect the Acorn's relay the same way, with the relay's common connected directly to DCM and the N/O contact connected directly to DI3 on the GS2. That would work. When the Acorn controls several inputs on the GS2, it would be cleaner to use a common row of electrically connected terminal blocks for all grounds, relay commons, DCM, etc. and then connect relay N/O contacts to signals on the GS2 or other devices.

[carbuthn]

Mike,
Thanks for taking the time to explain, I believe that the VFD ground and the DCM terminal are tied on the VFD, but I have not tested it.

I will added a tie between the Acorn common and the DCM block for the relays.

I am used to working with higher voltages (120 vac upto 500,000 vac transmission lines),
Chuck

[carbuthn]

MechTecMike,

Sorry for not getting back quicker. My lathe is setup with a PLC that controls power through an auxiliary relay to the ClearPath power supply and to the GS2-11PO VFD power input (applies power after 10 second delay). If I use the E-Stop to cause an EF fault on the VFD it will de-energize the VFD resetting the fault.

So at first I powered everything. Pressed the E-Stop, EF (external fault appeared on the VFD display), Acorn showed a Spindle Fault in the message section, Acorn Relay #6 energized closing the N.O. contact sending a reset to the deenergized VFD.

When I reset the E-Stop, relay #6 deenergized.

I changed power to the VFD so that it came from a different power supply (would not lose power).

Pressed E-Stop, VFD showed EF (external fault), Spindle Fault on the message section, Relay #6 energized, VFD didn't show reset. Reset the E-Stop, Relay #6 deenergize, but the VFD fault remained.

It works when the VFD is de-energized but not when power remains. Not sure what to try next.
Chuck