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.webp "single phase fan speed regulator")
.webp "single phase speed regulator")
EU declaration conformity
Fan speed controller | TK monitoring | remote start-stop | 5 A
Product description
5-speed transformer fan speed controller for single-phase motors with thermal contacts. The maximum motor current is 5 A.
The fan speed is set with the rotary switch in the OFF position. The motor can be remotely switched on or off via a digital input.
The TK monitoring function stops the motor in case of overheating. The motor restarts automatically after a power failure. Alarm and uncontrolled outputs can be used to control external devices to issue warnings or check normal operation.
The fan speed is controlled by a five-stage reduction of the motor voltage through an automatic transformer. This technology results in a perfectly sinusoidal output voltage and guarantees quiet motor operation.
The enclosure can be surface mounted and is IP54 rated against dirt, dust and moisture.
Additional specifications and description
5-step fan speed controller with extra features
The fan speed controller has a rotary switch with 5 positions. Through this switch, the fan speed can be set. It includes an OFF position with which to switch off the motor. The autotransformer technology reduces the motor voltage and the fan speed in 5 steps. This speed controller is therefore only suitable for voltage-controllable motors. If you are not sure whether your motor is voltage controllable, it is best to contact the motor manufacturer. Autotransformer technology is very reliable and robust. It generates a motor voltage with a perfect sinusoidal shape. This results in exceptionally quiet motor operation and extended service life. A special impregnated coating reduces the electrical noise from the autotransformers.
Outputs to control external devices
This controller has an extra output of 230 VAC, which is active when the motor is enabled. This output is either ON (230 Volt) or OFF (0 Volt), and it cannot be regulated to a value in between. Therefore it is called ‘unregulated output'. The maximum current of this output is 2 A. This output can be used to control an indicator lamp, open the closing grids of the air ducts, activate lighting, etc. The device connected to this output will operate simultaneously with the fan.
Automatic reset after power failure
In case of a power failure, this controller will automatically reset itself. When the power is restored, the motor will restart automatically. With standard fan speed controllers, after a power failure, the rotary switch must be turned to the OFF position and then back to the desired speed position manually. This is not necessary with the STRA1 series.
Fans with TK contact can be thermally monitored
This fan speed regulator offers the same speed control as the standard STR-1 series, but has some extra options. Among these options is the possibility to monitor thermal motor contacts. TK or thermal contacts monitor the temperature inside the motor windings. In case of the motor overheating, the TK monitoring function will disable the motor to prevent motor damage and will activate the alarm output. If the motor does not have TK contacts, both TK terminals of the controller must be bridged to simulate normal motor temperature.
Inputs offer remote control possibilities
Furthermore, the STRA1 series offers more control options thanks to the extra inputs. Via these inputs, the motor can be remotely enabled or disabled. This can be used, for example, to connect a door contact to control an air curtain. When the door is opened, the door contact activates the air curtain via the input of the STRA1 controller. The air curtain will run at a fixed speed. This speed can be set via the rotary switch. Another example is to connect a smoke alarm to the input. If a smoke alarm occurs, the motor will be disabled - regardless of the status of the other input. In this way, spread of the toxic smoke gases through the ventilation system can be slowed down.
Enclosure for indoor wall mounting
Make sure that the fan speed controller can cool sufficiently. This can be done by installing it in a cool place, best not in direct sunlight. The enclosure is designed and manufactured in-house. We use high-quality r-ABS VO (UL94) plastic. This material is flame extinguishing, very tough and offers good protection against impacts. It offers IP54 protection against the ingress of dust and water. This fan speed controller can be installed on a wall or panel indoors.
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