EC fans are controlled by a 0-10V signal, not by switching the mains supply. That’s the starting point for understanding where a 10k pot fits in.
When there’s a BMS, the 0-10V signal comes from the building management system. The BMS monitors CO2, temperature, occupancy or whatever the application calls for, and adjusts the signal accordingly. But not every installation has a BMS. Smaller buildings, individual tenancies, retrofit jobs, plenty of applications need manual speed control without the infrastructure of a full BMS.
A 10k potentiometer wired to the fan’s control input gives you exactly that. Turn the knob clockwise, the voltage rises, the fan speeds up. Turn it back, the fan slows.
How it works
The pot is connected between a reference voltage (usually 10V DC from the fan or an external supply) and ground. The wiper, the middle terminal outputs a voltage between 0V and 10V depending on the knob position. That signal goes to the fan’s speed control input.
The Powerform 10k pot comes pre-assembled with a knob, terminal block and the appropriate mounting hardware. It comes ready to connect.
The switch variant
EC fans are designed to be permanently powered. On/off is handled through a digital enable input, not by switching the mains supply. Cutting the power to stop the fan works, but it’s outside the design intent and can cause issues with some fan controllers.
The 10k pot with switch variant combines the speed pot with an HPM red dot switch on the same wallplate. The switch controls the enable input when it’s open, the fan stops. The electronics stay powered. This is the correct wiring approach for applications where residents or occupants need to be able to turn the fan off manually.
VSDs too
The same 10k pot works with Powerform’s RC10x series single phase VSDs and other 3 phase VSDs. The VSD takes a 0-10V input, the pot provides it. If you’re controlling an AC fan through a VSD and want a manual wallplate rather than a BMS signal, wire the pot to the VSD control input the same way.
Mounting options
Four options to suit different installations:
Wallplate. Comes with its own single-hole HPM Excel plate. Other options available up to 6 per wallplate
Wallplate with switch. 10k pot and HPM red dot switch on a two hole HPM Excel plate. Up to 3 sets per wallplate
HPM adaptor. Fits a standard HPM/Clipsal/etc wallplate, useful when the pot is being installed alongside other switches in an existing plate.
Bulkhead enclosure. Pot mounted in a black surface-mount enclosure, for mounting on ductwork, in plant rooms or anywhere a wall box isn’t practical.
DIN Rail. One or two pots mounted on a small DIN rail bracket, perfect for slotting into a switchboard
All variants are Australian made and come with a removable knob. We can supply other brands/types of wallplates if required. We can also laser mark or colour UV print the wallplate with your branding and indicator marks
If you’re working on a project with EC fans and need manual speed control, call us. We can advise on wiring and which variant suits the installation.
https://powerform.com.au/10k-potentiometers/
02 9460 8881