Recently I replaced the SP 3HP motor on my twin bag DC with a 4HP 3P motor and a VFD and thought you might like to see the VFD implementation and control panel I set up for it.
The DC is outside the shed in an enclosure and powered via the VFD located inside near the middle of one of the long walls of the shed. As my main wood dust making machinery is not more than 4m from the VFD I'm not adding a wireless remote although adding one in the future will be very easy to do.
Anyway here is the setup
Attachment 438063
1 = Mains power and E switch
2 = is a rotary switch with 5 positions: (a) no function (b) 40 Hz (c) 50 Hz (d) 60:Hz and (e) no function.
If the motor is running courtesy of switch 5, then positions (a) and (e) are where the speed can be set by the potentiometer (3)
When the other positions (b c d) are selected the DC motor operates at the selected speed.
3 = traditional potentiometer
4 = Delay timer. This OMORON delay timer is overkill for this purpose but I found a couple of them in an AC control box by the side of the road and they do make it very easy to perform things like delayed switching.
5 = ON/Off - Delay Off switch.
When this switch is UP the DC motor runs as per usually, Middle position switches DC motor OFF, DOWN position means the DC runs for the time selected by timer (4)
Usual operation will be
Start VFD using (1) followed by (5) flipped into the UP position
Select speed either with (2) or (3)
While working boost/decrease speed using (2) or (3) - why? because I hate noise and the large air flow makes a lot of noise.
When finished making dust reduce speed (and noise) for venting using (2) or (3) and toggle switch 5 to delay off position (DOWN)
Head off for coffee or lunch or snooze.
Using a preset speed is a second or 2 quicker than adjusting with the potentiometer which is handy when you are in a rush.
Attachment 438064
The multispeed switching capability I describe above is available on most VFDs
Most VFDs will have up to 6 or even 8 digital inputs which can be used to switch between the 6 or so speeds.
On the HY VFD they even have dedicated input terminals called SPL (Low Speed) SPM (Medium Speed) and SPH (high) for the switching lines (see red lines on photo below)
To select these speeds you just short the relevant terminal to DCM (digital ground) via an external switch - a rotary switch is a pretty easy way to do this rather than setting up a series of independent switches. About 8 parameters need to be changed in the software but it's fairly easy to do once you know how/
Attachment 438065