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Fan speed controller 400 V | day-night function | 4 A
Product description
This is a two-speed controller for 400 V motors with thermal contacts (TK). The maximum combined motor current is 4 A.
This controller has two distinct 5-step switches that allow you to choose between two different fan speeds. When the motor is turned on, a dry contact input allows you to select between the two speeds.
If the TK monitoring feature detects overheating, it shuts the motor. After a power outage, the motor will resume automatically.
External devices can be controlled by the alarm and unregulated outputs to create alerts or validate normal operation.
The fan speed is controlled by lowering the voltage of the motor using autotransformers. This technology generates an output voltage with a perfect sinusoidal form, ensuring silent motor running.
The enclosure is surface-mountable and provides IP54 protection against dirt, dust, and moisture entry.
The supply voltage is 400 VAC
Documents
Additional specifications and description
General
This feature allows users to establish different fan speed settings, such as one for day operation and another for night operation or to adapt to varying operating conditions.
Due to this function, the SC2A4 series enables energy savings and increased comfort. Users can adjust the fan speed based on specific requirements, ensuring that the fan operates at the most energy-efficient level for different periods or conditions.
The knob-based selection of fan speeds on the enclosure makes the SC2A4 series user-friendly and straightforward to operate, allowing for quick adjustments as needed. What is more, wiring is intuitive and simple!
![wiring scheme SC2A4](/en/files/article/image/description/sc2a4-40l55/wiring-sc2a4.jpg)
Connections
When connecting a three-phase fan motor, it is crucial to follow specific instructions to ensure safe and proper connections.
Firstly, identify the motor leads. Three-phase motors typically have six leads labeled as U, V, and W, representing the three phases. These leads serve as the motor outputs, while the controller is powered using the R, S, and T terminals.
Secondly, determine the appropriate wiring configuration. Refer to the motor nameplate or specifications to find the voltage rating of the motor. Ensure that it matches the available power supply voltage. Based on the motor voltage and the available power supply, you may need to wire the motor in either a delta (Δ) or wye (Y) configuration. The motor nameplate or manufacturer's documentation should provide instructions for the suitable wiring configuration for your specific motor model.
last, but not least, ensure proper grounding. Three-phase motors require proper grounding for safety purposes. Follow the grounding guidelines specified by local electrical codes to ensure a safe installation.
By following these guidelines, you can ensure that the wiring for your three-phase fan motor is done correctly, leading to safe and efficient operation.
Extras
Selection of two optimal speeds: The controller includes two separate 5-step rotary switches that allow you to select two optimal fan speeds. These speeds can be
![transformer controller with day and night functionality](/en/files/article/image/description/sc2a4-40l55/transformer-controller-with-two-knobs.jpg)
Dry contact input for speed switching: The controller utilizes a dry contact input to switch between the selected fan speeds while the motor is active. For example, an external clock can trigger the switch to high speed during the day and low speed during the night. This enables automated control and flexibility in adjusting fan speeds based on external triggers.
Remote ON/OFF: The fan motor can be remotely enabled or disabled using two inputs: normally open and normally closed. Connecting a remote switch to the normally open input allows remote control of motor activation and deactivation. Similarly, a smoke alarm connected to the normally closed input will automatically disable the motor in the event of a smoke alarm event. This provides convenient and flexible control of the fan motor from a distance.
Unregulated output for external devices: The controller features an additional unregulated output (single phase, 230 VAC) that becomes active when the motor is enabled. This output can be utilized to control external devices, such as operation indicators or dampers. For example, when the fan motor is deactivated, the damper can be closed, and when the fan motor is active, the damper can be opened. This allows coordinated control of associated equipment based on the fan motor status.
Thermal motor protection contacts: The controller can monitor thermal motor contacts (TK) that 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 lacks TK contacts, the controller's TK terminals must be bridged to simulate normal motor temperature. This ensures motor safety and prevents overheating-related issues.
Alarm output: In case of motor problems, such as overheating, an alarm output (230 VAC) is activated. This output can generate alerts or control warning indications, allowing prompt detection and response to motor issues. If the motor overheats, the TK monitoring function will disable the motor to prevent further damage.
Auto reset after power failure: In the event of a power failure, the controller has an automatic reset feature. When power is restored, the controller will reset itself, and the fan motor will restart automatically. This ensures seamless operation and eliminates the need for manual intervention after power disruptions.
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