Originally Posted by
Padawon01
Ok, to address the relay - Yes, I know the relay is nothing more than a switch. There is no power at the relay.
For simplicity -
I currently have no way to control activation of the VFD. The only way that I have found is to jump S1 to COM. S1 is set by default as the FWD signal for the spindle. S1 carries a voltage of 20v DC, and when jumped to COM, closes the circuit and drops to 0v DC. Closing this circuit activates the VFD and any signal from the control such as M3 and M5 now work. If I send M3 S8000, the spindle will start up and accelerate to 8000 RPM. I can now enter any value S7500-S18000 to control the RPM of the spindle. Entering and sending M5 stops the spindle and brings it to a stopped position.
My wiring is as follows:
1. 240v 3-wire outlet, 30A breaker in the main panel.
Wiring goes into:
2. 25A, 2-pole circuit breaker
Wiring goes into:
3. 25A, fast blow fuses - 2-pole
Wiring goes into:
4. 30A contactor, with 120v coil (motor load of 32A)
Wiring goes into:
5. EMI filter
Wiring goes into:
6. R, S, G, terminals at the VFD. Power to VFD complete
From VFD to Spindle:
1. 4-wire VFD cable with foil and braided shielding. Drain is terminated at the control panel into the ground bus. Power from VFD to spindle complete.
Power to motion control:
1. 120v terminal block in panel to DC power supply.
2. From DC power supply to motion control box. Stepper drivers and all necessary items contained and powered in same motion control box. Power to motion control complete.
Auxiliary wiring from motion control to VFD.
1. 0-10v signal wire to VFD AI1
2. Ground for signal wire to terminal ground on VFD
The following parameters are selected in the VFD:
1. P5.10=0 (2-wire control, the defined FWD/REV terminal command determines the direction - in this case, the FWD command is determined by S1 since it is set at FWD as a default setting (P5.01=1). Terminal S2 default is 4 (jog forward), but I set terminal S2 to REV (P5.02=2). To run the spindle, the voltage at S1 (20v) needs to go to ground to complete the circuit. This can be performed with the use of a jumper between S1 and COM.
The caveat -
When using a jumper between S1 and COM, both of these terminals cannot be connected to form a circuit PRIOR TO powering on the VFD. The VFD manual even states in the P5.10 control programming (on page 48)
"Note: when 2-wire control mode is active, the inverter will not run in following situation even if FWD/REV terminal is enabled:
**Coast to stop (press RUN and STOP/RST at the same time)
**Stop command from serial communication
**FWD/REV terminal is enabled before power on <-- in other words, if S1 and COM are jumped prior to power on, inverter will not run (no spindle control)
Relay - I am not misreading anything in the manual. When the relay is open, there is no continuity. When the relay is closed (in the case of VFD and spindle operation) the relay has positive continuity. I did ask their tech support for clarification on the relay to make sure of its operation since my machine and workstation are in two separate places.
One way to fix this VFD issue, is to use the relay on the motion control box. Seems easy enough, right? This relay is triggered whenever the spindle is activated via the motion control software. In normal circumstances, this should be a straight forward and easy fix, but it is not.
Whomever designed this feature in the Openbuilds Blackbox firmware, has the relay toggling on and off briefly when the motion controller powers on for the first time. When the relay is hooked to the VFD S1 and COM terminals, the VFD "sees" this as having S1 and COM jumped (closed circuit) prior to the VFD powering on, which nulls the ability to use the 0-10v control signal the way it was intended.
Tech support provided recommendation after recommendation, none of which worked. Rather than taking the most direct route possible, I had to change relay functions in the box and change programming for the "enable", even though the correct solution was right there - change the firmware to stop the motion control box from cycling the relay on/off on initial power up, and again when establishing communication from the port on the laptop. This is the correct solution. For whatever reason, the person was more intent on trying to find fault in everything that I said.
Spindle minimum RPM - When I start my spindle, I type in M3 S8000 - to start the spindle at 8000 RPM. I see no issue with this, I am the only person running this machine and I know not to run it at rpms lower than that for any significant amount of time. At most, I will run 10% and 25% to check function, but not much more than a minute or so.
Are you telling me that I need to have the minimum frequency programmed into the VFD because it will damage something, or are you telling me to set the minimum frequency because that simply acts as the point of lowest RPM to prevent accidentally running at low RPMs? If the latter, then I am not concerned about it at this point. I will make that adjustment once I am able to make a few test cuts in this range (~7200 rpm, 7500rpm and up). If the test cuts show a good value to use as my rpm "floor", then I will set it accordingly. I also plan to obtain the proper value from the manufacturer. In any case, unless it is damaging to my equipment in some way, I will set the minimum frequency at a later time.