Can I run multiple machines on one VFD?
Over the years we have occasionally been asked the question: "Can I run 2 machines off the same VFD with the use of a 3 phase change over switch?"
In short, this is not a practice recommended by any VFD manufacturer as doing so risks damage to the VFD (Variable Frequency Drive) and motor.
product specific programming
84 Engineering VFDs are programmed specifically to each application and motor. Some of the parameters are adjusted to optimise performance including:
- Maximum motor RPM
- Motor power requirements
- 2 pole or 4 pole motor
- Acceleration / deceleration rate
For example, a VFD tuned for disc grinder use is significantly different to the tune we run on our Shop Mate 48" belt grinder. If you were to run a disc using a belt grinder VFD - the disc would be spinning at over 4500rpm (Which we DO NOT recommend!)
Sensor-less Vector Technology
84 Engineering Variable Frequency Drives use 'sensor-less vector' technology. Sensor-less vector technology uses complex algorythms to calculate motor rpm and position using feedback readings from the motor.
When load is applied to the grinder causing the motor RPM to drop, the VFD compensates by sending more amperage to the motor and optimising output signal to maintain the target RPM.
For sensor-less technology to work correctly, the VFD needs to 'auto-tune' to the specific motor it is to be connected to.
Auto Tune
Auto-tuning is a process that occurs when connecting the motor and VFD for the first time. The VFD generates a detailed map of the motor by measuring variables including speed, torque and current whilst testing the motor at various frequencies and loads.
This data is specific to each individual motor and is saved to the VFD once the initial tune is complete. To use a different motor with the VFD, the unit should be re-flashed and auto-tuned to the new motor.
This is another reason that we do not recommend running multiple motors using the same VFD. The motor the that the VFD is optimised for will run as normal; however the motor that did not complete an auto-tune will be less efficient and potentially cause issues in time.
All 84 Engineering assembled grinders and motor-drive combos are auto-tuned prior to dispatch.
where can I buy a motor/vfd for my project?
Are you the DIY type and plan on making your own belt grinder or other piece of equipment requiring a variable speed motor? 84 Engineering now offer pre-wired VFD's with 0.75kw, 1kw and 1.5kw motor options.
As part of this package, we offer a free tuning service where you can talk to one of our team members about your specific requirements and we will program the parameters to suit your specific application.
The standard VFD/Drive packages are also great as a bolt on option to upgrade your old fixed speed 84 Engineering belt grinder to variable speed!
