Temperature based motor control
For controlling an HVAC system we generally take temperature as an indicator of comfortable thermal conditions. Even though temperature is not the only factor that affects our perception of thermal comfort, it is the major factor in comfort and is readily measured and controlled. HVAC systems are generally designed to handle peak cooling or heating loads that seldom, if ever, take place, so we must provide controls that can regulate the system output to meet the actual cooling or heating load at a given time.
Automatic controls for HVAC systems are used in place of manual to eliminate the need for constant human monitoring of a process, and, therefore, they reduce costs and provide more consistent and often improved performance.
The ultimate aim of every HVAC system and its controls is to provide a comfortable environment suitable for the process that is occurring in the facility. In most cases, the HVAC system purpose is to provide optimum thermal environment.
Temperatures is the major parameter to base ventilation on, especially when it comes to agricultural facilities such as grow rooms, greenhouses, sheds, stables, etc. Sentera’s temperature based controllers regulate simultaneously the speed of single-phase extraction and supply fans, some featuring the option to control a heater as well.
Sentera’s temperature based fan speed controllers regulate automatically based on the adjusted temperature setpoint and the ambient temperature measured by the connected temperature probe with an option for manual control.
Temperature measurement
To measure the temperature, a PT500 temperature sensor is necessary. For some models, it is prewired.
Temperature hysteresis
Temperature hysteresis
In a temperature-based controller, temperature hysteresis is defined by a minimum and maximum temperature value, where the heat will be turned on and off respectively. For example, if the temperature is to be maintained at 22°C with a hysteresis of 1°C, the cooling fan will activate when the temperature reaches 23°C and turn off when the temperature drops to 22°C.
Proportional range
The proportional range refers to the portion of the control output where the system response is directly proportional to the error signal. In simpler terms, it is the range within which the control system adjusts its output in proportion to the difference between the desired setpoint and the actual process variable.
Plug-and-play
Some of the series are ready for use, meaning they are prewired or all you need to do is plug the fan or heater cable into the provided sockets on the controller enclosure. This design eliminates the need for complex wiring or intricate setup procedures, making the installation process straightforward and efficient for the end user.
Standalone or Modbus operated
Some of Sentera’s temperature based variable fan speed controllers feature Modbus RTU communication, which means they can be operated using Sentera’s free software 3SM Center. However, all of them also feature jumpers to set the unit as a standalone device without the need to connect it to a computer.