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EU declaration conformity
Fan speed controller 400 V | TK monitoring | remote run-stop | 11 A
Product description
This 5-step fan speed controller for 3-phase 400 VAC motors features thermal contacts. The maximum motor current of 11 A. The speed is adjusted manually via the switch on the enclosure. The motor can be turned on or off remotely using the additional inputs.
For motor protection, STRA4 has a thermal monitoring function. In the event of motor overheating, the TK monitoring function disables the motor to prevent possible damage. The motor restarts automatically without the need of manual intervention in case of power failure.
STRA4 includes an alarm output and an unregulated output. The alarm output triggers external alerts. The unregulated output can control external equipment to confirm normal operation or enable connected devices.
Fan speed is controlled by reducing the motor voltage using transformer technology. This ensures that the output voltage has a perfect sine shape, guaranteeing smooth motor operation.
The controller is designed for wall mounting and its enclosure features IP54 ingress protection rating against particles and moisture.
Additional specifications and description
Autotransformer technology
Autotransformer technology, when used in fan speed controllers, can positively impact the lifespan of the motor. By reducing the motor voltage, autotransformer technology helps decrease the stress on the motor windings and other internal components. Operating the motor at lower voltages reduces the electrical and thermal stress on the motor, which can contribute to a longer service life.
Autotransformer technology generates a motor voltage with a perfect sinusoidal waveform. This smooth voltage output results in reduced electrical noise and vibration during motor operation. The absence of voltage spikes or irregularities helps minimize mechanical stresses on the motor's moving parts, further enhancing its longevity. When the motor voltage is reduced, the motor tends to generate less heat. Heat is one of the primary factors that can degrade motor insulation and other components over time. By operating the motor at lower voltages through autotransformer technology, the motor can dissipate heat more effectively, reducing the risk of overheating and extending its lifespan. Fan speed controllers employing autotransformer technology often incorporate various protective features.
Autotransformer technology is known for its reliability and robustness. The technology itself is designed to withstand the demands of motor control applications. The use of high-quality autotransformers and components in fan speed controllers contributes to the overall durability and longevity of the system.
TK monitoring for temperature control
Thermal motor protection helps to prevent the motor from operating under extreme conditions that could lead to a failure. For example, if the motor overheats, the TK monitoring function deactivates the motor, protecting it from damage. The STRA4 series features TK contacts for connecting to the motor thermal protection. Such protective mechanisms contribute to prolonging the motor lifespan. However, if the controlled motor does not feature thermal protection, the TK contacts should be bridged to simulate normal motor temperature.
Remote start-stop
The controller provides inputs for remote control of the motor. There are two input options: a normally open (NO) input and a normally closed (NC) input. By connecting a remote switch to the NO input, the motor can be remotely enabled or disabled. Additionally, a smoke alarm can be connected to the NC input. If a smoke alarm is triggered, regardless of the state of the other input, the motor will be disabled.
Unregulated output
As standard, an extra unregulated output (230 VAC, 2 A) is available on the controller. This output becomes active when the motor is enabled. It can be used to control external devices such as run indicators, dampers, or other equipment. For example, when the fan is deactivated, the damper can be closed, and when the fan is active, the damper can be opened using this output.
Alarm output
The controller features an alarm output (230 VAC) that is activated when motor problems occur. This output can be used to generate alerts or activate warning lights. For instance, in the event of motor overheating, the alarm output is activated, and the motor is disabled by the TK monitoring function to prevent further damage.
Auto reset
In the event of a power failure, the controller automatically resets itself. When the power is restored, the motor restarts automatically without the need for manual intervention.
Solid enclosure
The controller is housed in a high-quality steel enclosure. It is designed for surface mounting and provides an IP54 protection rating. This rating ensures protection against the ingress of dirt, dust, and moisture, making it suitable for indoor installations.
Autotransformer technology generates a motor voltage with a perfect sinusoidal waveform. This smooth voltage output results in reduced electrical noise and vibration during motor operation. The absence of voltage spikes or irregularities helps minimize mechanical stresses on the motor's moving parts, further enhancing its longevity. When the motor voltage is reduced, the motor tends to generate less heat. Heat is one of the primary factors that can degrade motor insulation and other components over time. By operating the motor at lower voltages through autotransformer technology, the motor can dissipate heat more effectively, reducing the risk of overheating and extending its lifespan. Fan speed controllers employing autotransformer technology often incorporate various protective features.
Autotransformer technology is known for its reliability and robustness. The technology itself is designed to withstand the demands of motor control applications. The use of high-quality autotransformers and components in fan speed controllers contributes to the overall durability and longevity of the system.
TK monitoring for temperature control
Thermal motor protection helps to prevent the motor from operating under extreme conditions that could lead to a failure. For example, if the motor overheats, the TK monitoring function deactivates the motor, protecting it from damage. The STRA4 series features TK contacts for connecting to the motor thermal protection. Such protective mechanisms contribute to prolonging the motor lifespan. However, if the controlled motor does not feature thermal protection, the TK contacts should be bridged to simulate normal motor temperature.
Remote start-stop
The controller provides inputs for remote control of the motor. There are two input options: a normally open (NO) input and a normally closed (NC) input. By connecting a remote switch to the NO input, the motor can be remotely enabled or disabled. Additionally, a smoke alarm can be connected to the NC input. If a smoke alarm is triggered, regardless of the state of the other input, the motor will be disabled.
Unregulated output
As standard, an extra unregulated output (230 VAC, 2 A) is available on the controller. This output becomes active when the motor is enabled. It can be used to control external devices such as run indicators, dampers, or other equipment. For example, when the fan is deactivated, the damper can be closed, and when the fan is active, the damper can be opened using this output.
Alarm output
The controller features an alarm output (230 VAC) that is activated when motor problems occur. This output can be used to generate alerts or activate warning lights. For instance, in the event of motor overheating, the alarm output is activated, and the motor is disabled by the TK monitoring function to prevent further damage.
Auto reset
In the event of a power failure, the controller automatically resets itself. When the power is restored, the motor restarts automatically without the need for manual intervention.
Solid enclosure
The controller is housed in a high-quality steel enclosure. It is designed for surface mounting and provides an IP54 protection rating. This rating ensures protection against the ingress of dirt, dust, and moisture, making it suitable for indoor installations.
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