EU declaration conformity
Fan speed controller | Modbus RTU controlled | 5 A
Product description
This transformer fan speed controller controls fan speed manually or on demand. It controls single-phase motors. The maximum motor current (combined) is 5 A. The supply voltage is 230 VAC.
Modbus communication is used to operate RTVS1. The required fan speed may be adjusted b using a Sentera HVAC sensor, potentiometer (SPV series), or a BMS system with Modbus RTU communication. Fan speed may be set manually or automatically based on temperature, relative humidity, CO2 and air quality (TVOC).
The fan speed is controlled by gradually adjusting the motor voltage. The autotransformer technique produces a motor voltage with perfect sinusoidal shape. This ensures that the motor runs quietly. The electrical noise from the autotransformers is reduced using a unique impregnated coating.
Surface mounting of the plastic enclosure is possible (IP54 protection).
Documents
Additional specifications and description
Transformer-based fan speed controllers offer a range of benefits, making them a desirable choice for speed control solutions. These controllers are known for their robustness, user-friendly nature, efficiency, and affordability. One significant advantage of using transformer-based control units is their ability to provide speed control without relying on electromagnetic excitation in motors. This feature makes them particularly suitable for environments where noise sensitivity is a concern. What you get by a transformer fan speed controller is: silent motor operation, control in steps and a controller with a long service life!
Modbus RTU Control
The RTVS combines proven transformer technology with Modbus RTU - a widely used communication protocol in industrial automation and control systems, designed for serial communication between devices over RS485 networks. Modbus RTU is often used to enable communication between devices such as sensors, actuators, controllers, and other industrial equipment.
In a Modbus RTU network, there is a master device that initiates communication with one or more slave devices. The master sends requests to the slaves to read or write data.
In manual mode, the desired fan speed can be set by a Building Management System (BMS) or a Modbus RTU master. The requested fan speed value is written via Modbus holding register 12.
In automatic mode, a Sentera HVAC sensor or an SPV series of potentiometers is connected to the RTVS1 controller. The type of connected device (sensor or potentiometer) is specified via Modbus register 18.
Fan speed is controlled by the connected device based on measured parameters like temperature, relative humidity, CO2 levels, air quality (TVOC), CO, NO2 if an HVAC sensor is connects and or by the SPV series that also feature Modbus RTU communication.
![fan sped controller with auto control](/en/files/article/image/description/rtvs1-50l22/oautomatic-fan-speed-controller.jpg)
Fan speed control in automatic mode
The controller offers two operating auto modes: auto forward mode and auto reverse mode, selected via holding register 11.
In forward mode, fan speed increases as the measured parameter value (such as temperature) increases. This mode is suitable for applications where increased cooling is needed as the temperature rises.
In reverse mode, fan speed decreases as the measured parameter value increases. This mode is useful for applications where reduced cooling is required as the temperature increases.
Unregulated output
The fan speed controller includes an extra unregulated output with a default setting to indicate alarms.
The functionality of this output can be configured using Modbus register 19. It can indicate alarms, motor operation, or be controlled using Modbus register 15.
Thermal motor protection (TK monitoring)
The fan speed controller can monitor thermal motor contacts (TK) that measure temperature in the motor windings. If the motor overheats, the TK monitoring function will activate and disable the motor in order to prevent damage. If the motor is not equipped with TK contacts, the TK monitoring function can be disabled using Modbus register 14.
Auto restart after power failure
If there is a power failure, the fan speed controller will automatically reset itself. When power is restored, the motor will restart automatically, ensuring continuous operation.
Enclosure type and protection
The fan speed controller is housed in an enclosure made of high-quality r-ABS plastic. This material offers heat resistance, toughness, and protection against impacts. The enclosure is designed for surface mounting and provides an IP54 protection rating, safeguarding the controller against dirt, dust, and moisture ingress.
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