Sentera has a wide range of products and solutions to control fans and monitor indoor air quality. Our product range has a modular structure, which offers enormous advantages. Sentera products are easy to install and they can work stand-alone. If the need changes, additional components can be added afterwards. The connected devices exchange information and work seamlessly together.
A good example is controlling an AC fan.
Variable fan speed control
Controlling the speed of an AC fan can be done using a frequency inverter. Many people fear the complexity of this type of speed controller. No need to fear: frequency inverters in our product range are easy to install and in many cases – especially AC fan speed control - the default settings should not be changed. AC fan speed can be adjusted via the up and down buttons below the display. Controlling an AC fan with a frequency converter offers high energy efficiency. At low speed, little energy is wasted due to heat losses. AC fan speed can be variably controlled over a wide range. The standard frequency inverters must be installed in an electrical cabinet. The IP66 variant may simply be installed on a panel or wall as long as sufficient cooling is possible (do not mount enclosed). Protection against direct sunlight and rain is a guarantee for a longer service life.
How to control AC fan speed remotely?
If desired, an external potentiometer can be added to start or stop the AC fan and control the speed from a different location. This external rotary knob can be connected via a 3 wire cable. No additional settings are required on frequency inverter. Via a switch (connected to input 3 of the frequency converter) it is possible to switch between the external rotary knob and a fixed set speed (parameter 20). This standard functionality offers many possibilities for coming up with creative control solutions.
In case additional control is desired, such as a day-week regime or remote control, a potentiometer with Modbus RTU communication can be used. This can then be connected to a building management system or to SenteraWeb - the online HVAC portal to overrule the local control.
Demand based fan speed control
Would you rather control the fan speed automatically? The higher the CO2 concentration, the higher the fan speed? No problem! In that case you can connect a CO2 sensor to the frequency converter. The output signal of the CO2 sensor can be connected to the frequency converter via a cable with 2 wires. This is also possible without making additional settings on the frequency converter.
All Sentera HVAC sensors have Modbus communication. This means that also here it is possible to connect the sensor to a building management system or to SenteraWeb - the online HVAC portal for remote control or data logging.
Remote AND demand based fan speed control?
For those who really can't choose, there is also a solution. The external rotary knob and the CO2 sensor can both be used to control the fan speed! Via an external switch you can choose which of the two controls you use. This is not that complicated to realize. Both the rotary knob and the CO2 sensor are connected to the frequency converter (inputs 3 and 4). The selector switch is connected to input 2 of the frequency inverter. The motor can be started or stopped via input 1 - this is possible with the contact of the rotary knob.
To enable this operation, parameter 12 of the frequency inverter must be changed to value 5. Changing the parameters of the frequency drive is possible using the keys below the display. Once that is done, it works!
All in all, not that complex...