VFD output fluctuates, no max speed
I’ve had my VFD running my spindle with manual speed control (panel potentiometer) for a while with no issue. I thought it would be useful to control the spindle speed using my Centroid Acorn controller 0-10V output.
But, the speed fluctuates randomly and won’t go higher than about 20%. I’ve attached a video showing the behavior at 18,000 RPM (max) setting on the controller. Connections are per the attached diagram from Centroid.
VFD is a Simphoenix E500 running an HQD 2.2kW spindle. I bought the hardware from https://www.automationtechnologiesinc.com/ and they have been helpful in verifying all VFD settings. The issue doesn’t seem to be with the Acorn, I have measured a steady 10.2V output at full RPM setting.
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Re: VFD output fluctuates, no max speed
This type behavior is often caused because the wire size running from the Acorn to the VFD is to small of a gauge limited current. Make sure you have at least 22 AWG. The longer that cable normally require one wire gauge larger like 24 AWG. I have a VFD and acorn and had this problem
Russ
Re: VFD output fluctuates, no max speed
Sounds like Parameters not set correct, it should not be able to run at that speed.Originally Posted by kmagyoyo
What Parameters have you set??
Is the Voltage the same at the VFD Drive input 10.2v??
Mactec54
Re: VFD output fluctuates, no max speed
24” wire to VFD from Acorn is a pair of 16 AWG wires so I don’t think it’s a voltage drop issue. Possibly shielding?
I too suspect a parameter is out of whack but I have triple checked with what Simphoenix recommends.
Parameters are set as follows (300 Hz spindle):
F0.04= 300
F0.05=10
F0.06=10
F0.11=0
F0.12=300
F0.13=220
F1.00 =0
F1.01 =10V
F1.03=0
F1.04 =300
F1.08=11 ( Terminal X1 as a Run)
F1.14=8 ( Inverter Fault signal Output)
The Simphoenix manual shows 3 wires to the VFD 10V input, but I suspect that is in the case of a remote potentiometer rather than a 0-10V DC supply from the controller.
Re: VFD output fluctuates, no max speed
Is it similar to below spindle speed problem?
How to correct actual speed of spindle
http://cncmakers.com/cnc/controllers/CNC_Controller_System/CNC_Retrofit_Package.html
Re: VFD output fluctuates, no max speed
No, you don't need to worry about 3 wires, the 3rd wire is if the Board requires a 10v supply, and yours does not.
Are the 0-10v wires Twisted pair??
Simphoenix would not know what your spindle needs, I'm surprised that you did not damage the spindle with no minimum speed setting
Try these settings not a lot of difference but it only takes (1) Parameter not set or be incorrectly set, to cause problems
Mactec54
F0.00=1 (F0.00=3 Keypad Potentiometer Control) (F0.00=1 0-10v Remote control)
F0.01=300
F0.02=1001 (F0.02=1 Run/Stop Keypad Control) (F0.02=1001 for Remote Terminal Control)
F0.03= 120
F0.04=300 (Max Motor Frequency)
F0.05=5 To 8 (Adjustable Acceleration)
F0.06=5 To 8 (Adjustable Deceleration)
F0.07=1 (S-Curve for Acceleration and Deceleration)
F0.12=300 (Motor Rated Frequency)
F0.13=220 (Motor Rated Volts)
F1.03=120
F1.04=300
F2.00=50
F2.01=2
F2.07= 100% (VFD Max Amps Match Spindle Max Amps Adjust Percentage to Suite)
(If VFD Amps are More Than the Spindle Then the Percentage Must Be Adjusted to Suite)
F2.19=1 (Number of Pole Pairs)
F3.13=150%
Mactec54
Re: VFD output fluctuates, no max speed
0-10V wires are not twisted pair, just 16 AWG stranded primary wire. Should they be twisted?
Here’s the spindle nameplate (why do these forums always turn pics sideways??):
Re: VFD output fluctuates, no max speed
Either Twisted pair (like the Snip) or shielded and the shield terminated correctly.0-10V wires are not twisted pair, just 16 AWG stranded primary wire. Should they be twisted?
Here’s the spindle nameplate (why do these forums always turn pics sideways??):
Not sure why the photos are sideways I don't have that problem.
Mactec54
Re: VFD output fluctuates, no max speed
Problem solved.
I noticed that when I moved the 0-10V wire while the spindle was running, the speed would change. I have chased EMI issues all along while building this machine, so I suppose I should have guessed that first.
I twisted the wires and the speed is rock solid. Also adjusted the minimum input voltage…for whatever reason it’s not 0V at minimum speed from the Acorn. Actually it’s 3.6V so when I set the F1.00 to 3.6 I get the exact minimum frequency output of 100 Hz (to achieve specified 6,000 RPM minimum spindle speed).
Thanks @mactec54, I did tweak a few of the settings as you suggested. I didn’t change F2.19 (currently at F2.19=2) and all seems to run fine. The spindle nameplate states 2 poles but the use of “pairs” is confusing. Should I still change that setting?
Re: VFD output fluctuates, no max speed
Yes 2 Pole =1 Pair this needs to be set correct 4 Pole=2 Pair your spindle is 2 Pole so needs to be set to (1)
Your spindle being air cooled just keep a check on the temperature at low speed as your minimum may be too low (100Hz) for an air-cooled spindle.
Mactec54
Re: VFD output fluctuates, no max speed
Did you figure out why you were getting voltage something other than 0 volts ? I am getting 1.2 ish volts with the spindle stopped, then when I start the spindle, the voltage is only 1.4 ish where it wants 1.66 in the spindle bench test, if I enter 1.5 in the first option, the rest land correctly. Not sure what is going on.
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