Controlling VFD power

I'm retrofitting my router to a VFD and spindle but need some info on how to control the VFD power. It is a 2.2 KW unit with 1 phase 240VAC input and 3 phase 240V output. As per the manual, the mains input goes to a breaker, then a contactor, then a line filter and then the VFD but it doesn't show what controls the contactor. One option is to use the 120V input power to energize the contactor whenever the rest of the control box is turned on. Another is to use an output of the 7i96 to control a relay to turn on the contactor. The problem with that however is that linuxcnc won't even start if the Modbus is not active (according to HY_GT_VFD component). How do setups with small power VFDs generally wire up the power control circuitry? TIA
Jim

I am new to linuxcnc but have lots of experience wiring motors contractors and vfd's. I would wire the contractor to come on when you turn the machine on. The vfd won't run the spindle until commanded.

All of the large commercial routers I work with at work have the VFDs powered all the time when the main machine's power disconnect is on (only fuses between the disconnect and the VFD). Then all of these are then controlling the spindle by the VFD's command inputs either directly to the VFD's terminal strip or a serial connection (most use the terminal strip, some a combination of both).

i use hy_vfd for my non gt series. with an output of the 5i23 I control a relay for the power and it works .. I don't know the gt series.

The GT series uses a DSP to implement sensorless vector control of a synchronous AC motor. Among other things, this provides higher torque at low RPMs. I just noticed that the latest 2.7.15 release fixes a bug with HY_GT_VFD. I don't know if this will fix the issue with linuxcnc not starting without an active RS-485 bus but I will find out soon enough. If it does, then the VFD can be switched on and off with a 7i96 output. (through a relay of course). This would kill the power to the VFD and spindle in the case of an ESTOP condition. Otherwise the contactor trigger will be wired to the 120V input. Thank you all for the replies.

the loader of the vfd did you put it in the postgui.hal file? it must be loaded when everything is ready.

So far I've only been testing through halrun but it will go into the postgui.hal file. The problem is that in order for everything to be ready, the modbus client needs to be active and it won't be active until the VFD is powered on. Therefore I can't use the linuxcnc gui to turn on the VFD because linuxcnc won't start until all the HAL components are ready. It's OK though, I will just power on the VFD when the controller power comes on.

when i start linuxcnc the vfd relay closes immediately, it finishes loading the interface and after a moment the modbus light turns green. however i have the vfd initialization line in postgui.

Does anyone have a working HAL file for the Huanyang GT series VFD they are willing to share? I run :
halcmd loadusr -Wn vfd hy_gt_vfd -d /dev/ttyUSB0 -S 24000 -F 400 -f 40
and get the following output:
hy_gt_vfd: device='/dev/ttyUSB0', baud=38400, parity='N', bits=8, stopbits=1, address=1
[01][03][30][00][00][01][8B][0A]
Waiting for a confirmation...
<01><03><02><00><00><B8><44>
[01][03][30][02][00][01][2A][CA]
Waiting for a confirmation...
<01><03><02><0D><2D><7C><C9>
[01][03][30][03][00][01][7B][0A]
Waiting for a confirmation...
<01><03><02><00><00><B8><44>
[01][03][30][04][00][01][CA][CB]
Waiting for a confirmation...
<01><03><02><00><00><B8><44>
[01][03][30][05][00][01][9B][0B]
Waiting for a confirmation...
etc. etc.
All VFD registers are set according to linuxcnc.org/docs/2.7/html/man/man1/hy_gt_vfd.1.html
As far as I can tell, there is no documentation for the hy_gt_vfd in 2.8 or 2.9 documentation.What about the MB2HAL component - maybe I should be using that? It looks way more complicated.

The above info was with -v (verbose) flag on. According to the manual, it appears that the requests are actually being responded to. If I omit the -v flag, the output is:
hy_gt_vfd: device='/dev/ttyUSB0', baud=38400, parity='N', bits=8, stopbits=1, address=1
Waiting for component 'vfd' to become ready.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................etc. etc.
The hy_gt_vfd component never becomes ready.