Impacts of poorly functioning ventilation system on inhabitants
Poorly functioning ventilation system has a huge impact on human health. In most cases in which the ventilation system cannot extract a huge percentage of most common pollutants like carbon dioxide, volatile organic compounds or airborne pathogens from the rooms, the air is still contaminated. In such situations, inhabitants may feel dizzy, sick and have some negative impacts on their skin like increased dryness, irritation and sensitivity, acne, infections or even allergic reaction due to increased levels of pollen. However, the bad condition of the ventilation system can also reflect on the installed devices and the fan in it. When the system does not work properly, most of the pollutants from the extracted air clog the installed devices and the fan through the connection elements (pipes, nozzles and etc.) as the devices could wear out, overheat, reduce working efficiency, electrical issues would appear or mostly common to reduce the airflow, which still has a huge impact on human health. This is a clear example of how the ventilation system can reflect on the long-term exploitation life of the installed devices and the human health.
Variable fan speed control through an analogue input
In HVAC control systems, the analogue input is typically used with input sensors in order to produce a voltage, current or resistance change in response to an environmental variations or system measurements or sometimes with a control device, such as a potentiometer, providing the needed output signal. The requested fan speed can be set via the analogue input signal. This analogue signal can be between 0 and 10 V or between 0 and 20 mA and in ascending or descending mode, depending on the used version from the EVS, EVSS, MVS, MVSS and TVSS series of fan speed controllers. In ascending mode, the motor will run at low speed when the analogue signal is at its minimum value (0 V), as the motor will run at high speed when the analogue input is maximum (10 V). In descending mode, the operation is inversed: when there is no 0-10 V input signal available, you can connect an external 10 KOhm potentiometer via the integrated 12 VDC power supply. Sentera has developed many convenient solutions for remote control of the fan speed or the air curtain, which are available on our website. Depending on the application and the required devices, you receive a clear vision for remote and automatic regulating of the fan speed, depending on the measured values of temperature, relative humidity or VOCs.
Connect a sensor or a potentiometer for an automatic control of the fan speed
Sensors in control systems often produce analogue signals that vary in voltage, current or resistance based on the measured parameters of temperature, humidity or other crucial for the human health environmental conditions. For instance, a temperature sensor can generate an output voltage signal proportional to the measured temperature values.
Analogue inputs are designed to capture and interpret signals from sensors that monitor environmental variations or specific parameters within the whole ventilation system system. This can include temperature sensors, pressure sensors, light sensors and other.
When we continuously monitor the information, given from the analogue signals from sensors, the control system can make real-time adjustments in order to maintain the desired from the inhabitants conditions or quickly respond to changes in the environment. This is how the ventilation should really work to have a good impact on the health of the human organism.
Various types of sensors, controllers and transmitters with analogue outputs could be connected to devices with analogue input from the variable fan speed controller series of Sentera. The control system uses the signals from these devices to regulate the operation of heating or cooling elements, fans, and other components to maintain a comfortable indoor environment. The analogue input can also be connected to an external potentiometer providing 0-10 V control signal. In this way, a motor can be regulated based on the input information provided by the potentiometer. You can use Sentera’s potentiometer series LTV, MTP and MTV and see our solution examples of connecting variable fan speed controllers and potentiometers, available on our website.
Standalone or Modbus operation mode
The variable fan speed controller series (EVS, EVSS, MVS, MVSS and TVSS) feature two types of operation modes – standalone and via Modbus RTU communication. In standalone mode, there’s no need to connect the fan speed controller to a computer in order to operate with the device. All you have to do is use the integrated dip switches or trimmers to set the desired speed of the fan directly through the device. If the fan speed controller is in Modbus operation mode, you can operate the chosen device using the Sentera’s free software suite 3SM Center. Sentera’s variable fan speed controllers do have an integrated Modbus RTU and we share the common opinion that the Modbus RTU communication still is the easiest way to connect devices and receive information from them.
Trimmers for setting the desired fan speed Sentera’s variable fan speed controllers have an internal minimum speed trimmer built in, intended for setting the minimum speed sufficiently high to prevent motor overheating and buzzing at low speeds. This is a one-time screwdriver adjustment to an exact desired value and with its help you can avoid motor stalling. Apart from Sentera's standard minimum speed trimmer, some of the variable fan speed controllers feature a maximum or maximum speed trimmer. Thanks to it, the maximum speed of the fan can be restricted, irrespective of the potentiometer position. Using the two trimmers, you can set the speed within the desired limits and still save energy saving and extend the motor service life.
Thermal motor protection in case of overheating
Some series of the fan speed controllers offer thermal motor protection (TK monitoring) against eventual motor heating. This option is available only in MVSS, TVSS and EVSS series of variable fan speed controllers. The thermal contacts measure the temperature in the motor windings and when an extreme motor overheating is detected, the TK function will shut down the motor in order to prevent motor damage.
Two types of enclosure, made from high-quality plastic
The plastic enclosures for variable fan speed controllers are designed with sustainability in mind. They offer robust protection for the internal components of fan speed controllers while being lightweight and durable. These enclosures can withstand various environmental conditions without compromising on performance. Additionally, their production process emphasizes energy efficiency and minimal waste generation. The enclosure of the variable fan speed controller series is made of high-quality r-ABS VO (UL94) type plastic, as it offers two types of mounting – DIN rail or surface, depending on the chosen series of the devices. All of the enclosures of the fan speed controller are made with an IP protection rating (IP30 or IP54, depending on the version chosen) against ingress of dirt, dust and moisture.