Manual motor control
In the context of manual motor control for AC fans, the utilization of variable speed controllers with a potentiometer is a practical solution. These controllers are designed to manage single-phase voltage controllable motors, supporting a maximum current of 10 A. The integrated potentiometer is used to set up the speed of the connected AC fan.
The utilized TRIAC technology provides smooth manual motor speed control and air flow control respectively. Operation of the controllers is based on output voltage control with a TRIAC voltage regulator.
Several fans may be connected to one controller if their total current does not exceed the maximum permissible controller current.
TRIAC-based controllers boast high control efficiency and accuracy. However, when running in low-speed mode the fans may generate unusual noise, so these types of controllers are not the best choice for low-speed applications. The recommended speed control range is 60 - 100%.
Minimum speed trimmer
The internal minimum speed trimmer incorporated in Sentera’s variable fan speed controllers is 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 a desired value.
Maximum speed trimmer
Apart from the Sentera standard minimum speed trimmer, some of the variable fan speed controllers in this group feature a maximum speed trimmer, too. 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 thus realizing energy saving and extending the motor service life.
Kick start
Some series feature a kick start mode, meaning that when enabled, the fan starts running at maximum speed for a limited time period. This feature contributes to improved efficiency and responsiveness of the fan control system to meet specific environmental or comfort requirements, such as:
• Quick cooling or heating: The initial burst of maximum speed helps in rapidly achieving the desired temperature in a room.
• Ventilation boost: In scenarios where immediate and enhanced ventilation is required, the kick start mode ensures a rapid increase in airflow, improving air circulation.
• Clearing residual heat or cold: Before adjusting to the desired operational speed, the kick start mode helps in removing any residual heat or cold that might be present in the system, providing a fresh start for temperature control.
• Overcoming inertia: In certain motor systems, the kick start is used to overcome the inertia of the fan blades, ensuring a smooth start-up process.
Safety features
Some of the series feature additional connections in case the connected motor features thermal protection. These controllers have the capability to monitor these thermal motor contacts. This monitoring function allows the controller to assess the temperature conditions of the motor. In the event of detected motor overheating, the TK monitoring function takes preventive action by disabling the motor. This is a protective measure to avoid permanent damage to the motor. Simultaneously, when the motor is disabled due to overheating, the alarm output is activated. This provides a signal indicating motor problems. To make this alarm visible or audible, external devices like buzzers or indicator lights can be connected to the alarm output. This ensures that operators or maintenance personnel are promptly alerted to the motor issue.
Modbus RTU
Thanks to the featured Modbus RTU communication, a variable fan speed controller can turn into a hybrid, providing both manual operation using the keyboard and remote control using Modbus protocol allowing enhanced features and settings.
Different enclosures
Sentera offers manually operated variable fan speed controllers with different IP protection rating and mounting possibilities:
• DIN rail mounted enclosures designed for mounting electrical equipment in a control cabinet featuring IP30 rating
• Industrial enclosures suited for industrial settings, providing robust protection in demanding environments featuring IP54 rating
• Residential enclosures meeting the specific needs and aesthetic considerations of residential installations; these can be surface mounted or built into a wall and, depending on the mounting option, the ingress protection rating is either IP44 or IP54.