BTRN-1 • Auto transformer fan speed controller

Why transformer-based fan speed control

Transformer controllers offer several advantages as a speed control solution. They are robust, easy-to-use, efficient, and affordable. One notable benefit is the absence of electromagnetic excitation in motors, making them suitable for noise-sensitive environments. With a transformer fan speed controller, you can enjoy silent motor operation, convenient step-based control, and a long-lasting controller at a reasonable cost.

Simplified 5-step fan speed control

5-step fan speed controllers find extensive application in industrial kitchens, warehouses, and other industrial settings. They serve as straightforward controls for regulating extractor hoods or exhaust fans. These controllers allow for adjusting the fan speed in five steps, ranging from standstill to maximum speed. They are plug-and-play devices, requiring no configuration or programming. This makes AC fan speed control hassle-free and convenient.

The technology

This is a fan speed controller for single-phase motors. It features a built-in rotary switch that allows you to select one of the five speeds. Autotransformer technology is utilized to decrease the motor voltage and adjust the fan speed in these five steps. Autotransformer technology is highly reliable and durable, producing a motor voltage with a smooth sinusoidal waveform. This results in exceptionally quiet motor operation and an extended service life. The autotransformers incorporates in the STR-1 are impregnated with a special material that reduces electrical noise.

Application

The series is designed specifically to control AC fans by reducing the motor voltage. AC fans operate using alternating current and convert it into mechanical power. That is why they are compatible only with voltage controllable motors. It is possible to connect multiple motors to the controller, provided that the current limit is not exceeded. In such cases, all connected motors will operate at the same speed. If you are uncertain about the type of motor you have, it is strongly recommended to carefully review the accompanying documentation or contact the motor manufacturer for further assistance.

Unregulated output

The fan speed controller features an additional unregulated output (230 VAC) that becomes active when the motor is enabled. This output is either ON (230 Volt) or OFF (0 Volt) and is therefore referred to as the "unregulated output." It has a maximum current rating of 2 A. This output is commonly utilized to control various external devices, such as a run indicator, damper, relay, and more. For instance, when the fan is not running, the damper is closed, and when the fan is active, the damper opens.

Rotary switch with built-in mechanical time delay

It is important that you do not operate the rotary switch too quickly. The switch has a built-in mechanical time delay. This is important to prevent internal sparking during switching. Rapid rotation of the switch can bypass this time delay mechanism. In such cases, the device will remain internally in the "0" position (OFF position) even though the switch has been turned to a different speed setting. Therefore, it is advisable to rotate the rotary switch at a moderate pace, allowing the mechanical time delay to function correctly.

Solid enclosure

To ensure optimal cooling performance, it is important to ensure that the fan speed controller is installed in a location with sufficient airflow. It is recommended to install the controller in a cool area, preferably avoiding direct sunlight. The enclosure of the controller is designed and manufactured in-house using high-quality r-ABS VO (UL94) plastic. This material is flame extinguishing, highly durable, and provides excellent protection against impacts. The enclosure has an IP54 protection rating, offering resistance against dust ingress and protection against water splashes. The fan speed controller is suitable for installation on a wall or panel indoors, ensuring proper functionality and protection.