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I have a Huanyang VFD and spindle connected to a Buildbotics controller, communicating by RS485. It seems to work okay, except for the speed. For example, if I request 10000rpm, the Buildbotics controller will show the request and actual speed of 10000, but the VFD display will show 4799rpm.
Any ideas what could be wrong?
There could be any number of problems, and I don't know your controller.Quote:
Originally Posted by garrett1812
However there are a few common issues with setting up a VFD on a spindle.
1) Your controller will probably be setting the reference frequency, not the RPM. If your spindle was a 4 pole motor then the frequency needs to be double that for a 2 pole motor to achieve the same RPM. So your controller may need to be set to output the frequency for a 4 pole spindle. Not sure if you have that setting in your controller.
2) The VFD may be incorrectly set up for a 4 pole motor, so it would display the RPM as half that of a 2 pole motor. If it was a actually a 2 pole motor it would be doing the correct RPM but displaying incorrectly on the VFD.
3) There may be a maximum frequency limit set up in the VFD which is just limiting/capping the RPM. Not sure if the RPM is displaying half at various speeds, or just at that particular speed.
4) You may have other settings incorrect in the VFD such as nominal current, nominal voltage etc. which is causing it to drive very inefficiently and not achieve the correct RPM. This would usually trip out safety settings in the VFD of it was set up so badly, so less likely the issue.
5) You may just have a RPM/Frequency Scale Setting on the controller that is incorrect.
6) The RS232 Settings could be incorrect and it is getting the commands jumbled. This would usually result in some communications error message on the VFD, but maybe not. It could just be missing some characters, or reading them incorrectly. RPM would likely be erratic and unpredictable in this case.
7) Some VFDs expect frequency * 10 as they don't support a decimal place in the value. So 104.5 needs to be 1045. This would not explain a half or double result
8) The VFD may just be expecting different information, for example the controller may be sending frequency, but the VFD is expecting a percent of max value. Maybe the controller is expecting a value through the RS232 that is equivalent to the data it would receive from its analogue input, which would be some binary value like 1024, 2048, 4096 which would act like a percentage type command but needs to be scaled accordingly. Need to read the VFD manual to see what data it is expecting to receive to set the frequency.
These are generic issues that arise with VFDs, not specific to your hardware
Thanks for all the feedback RoboDavo!
My VFD is the Huanyang HY03D011B (110V, 3.0KW).
1) No, I don't see any setting like this in the controller.
2) I am not sure. I don't have this with any of the (minimal) documentation with the spindle. It is a Huanyang GDZ-65-800C (800W, 110V, 400Hz, 24000RPM).
3) It happens for any speed.
1000rpm -> 475rpm
5000rpm -> 2395rpm
10000rpm -> 4795rom
20000rpm ->9595rpm
I will check all of the settings again, to make sure I am not missing anything.
What is the corresponding speed of the CNC 10V analog voltage? What is the maximum speed of the VFD speed command? These two values should be the same.Quote:
Originally Posted by garrett1812
In my controller the min and max speeds are set to 0rpm and 24000rpm, respectively. I don't see any settings with speed in the VFD.
I just did a factory reset and put in these settings. Still the same results. Any other ideas?
PD000 = 0 unlock settings
PD001 = 2 command source RS485
PD002 = 2 speed/frequency source RS485
PD005 = 400 max operating frequency
PD004 = 400 base frequency
PD003 = 400 intermediate frequency
PD072 = 400 higher analog frequency
PD008 = 110 max voltage
PD141 = 110 rated motor voltage
PD142 = 7 rated motor current
PD163 = 1 modbus ID 1
PD164 = 1 9600 baud
PD165 = 3 8 bit, no parity, RTU mode
PD000 = 1 lock settings
Solved!
I set PD144 to 3000 and all is working now. Didn't even see this setting before, but someone pointed me in the right direction.