EU declaration conformity
Three phase fan speed controller | calendar function | 11 A
Product description
This fan speed controller is designed for controlling 3-phase 400 V motors. Its maximum combined current of 11 A.
The calendar function allows configuring two optimal motor speeds, and the timer with a day-week configuration enables automatic switching between these speeds based on predefined schedules.
To ensure motor safety, the controller includes a TK monitoring function that monitors motor temperature. If overheating is detected, the controller will deactivate the motor to prevent damage.
In the event of a power failure, the controller is equipped with an automatic restart feature., i.e. once the power is restored, the motor will automatically restart without the need for manual intervention.
The AC fan speed control is achieved by reducing the motor voltage using autotransformer technology. This technology generates a motor voltage with a perfect sinusoidal waveform, ensuring smooth and quiet motor operation.
The enclosure of the controller is suitable for surface mounting indoors and has an IP54 rating, providing protection against dust and offering resistance to water splashes.
The supply voltage for the controller is 400 VAC.
Documents
Additional specifications and description
It utilized transformer-based technology to reduce motor voltage in steps (0-130-170-210-250-290-330-400 V). This method ensures a smooth sinusoidal waveform, resulting in quiet motor operation and an extended motor lifespan. During commissioning, you can select high and low speeds from the available output voltages. The high and low speed operation time ranges can be configured using the built-in clock, allowing for precise control, such as day/night variations.
Built-in clock and autonomous operation
The controller has a built-in clock, enabling it to work autonomously. Two optimal speeds (high and low) can be configured from the range of voltage options. The clock also allows you to set the high and low speed operation times and motor stop times, providing control over prolonged periods without the need for frequent manual adjustments.
Day-week timer
The controller features a built-in day-week timer that allows you to set different fan speeds for different times of the day or week. This provides flexibility in selecting the optimal fan speeds based on specific time periods.
Remote start-stop
You can remotely enable or disable the motor connected to the controller using two input options: one that is normally open and another that is normally closed. This remote start-stop capability adds convenience and control to the operation of the motor-driven fan system.
![transformer controller for 11 A fans](/en/files/article/image/description/st2r4110l55/controller-for-11-a-fans-with-calendar-function.jpg)
Thermal motor protection
The controller can monitor thermal motor contacts (TK or thermal contacts) to measure the temperature in the motor windings. If the motor overheats, the TK monitoring function will disable the motor to prevent damage. In cases where the motor does not have TK contacts, the TK terminals should be bridged to simulate normal motor temperature.
Unregulated output
The ST2R4 provides an unregulated output of 230 VAC that is active when the motor is enabled. This output can be used to control external devices such as operation indicators or damper actuators. For example, it can be used to open dampers when the fan is active and close them when the fan is deactivated. As standards, its maximum current is 2 A.
Auto reset after power failure
In the event of a power failure, the controller will automatically reset itself. When the power is restored, the motor will restart automatically, ensuring seamless operation after power interruptions.
Alarm output
The controller has an alarm output that is activated in case of a motor problem. This feature can be used to trigger alerts, such as controlling a warning light indicator to alarm of issues with the motor or the system.
Metal enclosure
The ST2R4 is housed in a high-quality steel enclosure with paint coating and an IP54 protection rating. This rating ensures that the controller is resistant to dirt, dust, and moisture, making it suitable for operation in various environmental conditions.
Wiring guidelines
When wiring a three-phase fan motor, specific guidelines need to be followed to ensure correct connections and safe operation. The motor leads are typically labeled U, V, and W for the three phases, while the controller is supplied using the R, S and T terminals. The motor voltage should match the available power supply voltage. Depending on the motor voltage and power supply, the motor may need to be wired in either a delta (Δ) or star (Y) configuration, as indicated by the motor nameplate or manufacturer's documentation. Grounding guidelines specified by local electrical codes should also be followed.
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