Description
Parts and characteristics
- Microprocessor system with programme and system data stored in nonvolatile memory
- Double-stack terminal block for supply voltage connection and communication cable
- Inputs and outputs with screw terminals
Construction features
- PCB with terminals enclosed in a casing
- Casing is to be screw-fixed to the installation surface
- Casing with knockouts for cables
Materials and surfaces
Maintenance
- Maintenance-free as construction and materials are not subject to wear
Function
Functional description
Adjustable air terminal devices with actuators are used to achieve the best possible air distribution in high and large rooms with changing thermal loads. Type LON-WA TDC control modules control actuators based on the supply air to room air difference.
Supply air temperature and room air temperature are measured with external sensors and transmitted as voltage signals or LonWorks network variables Characteristic curve values translate into discharge angles, and the actuators are set accordingly.
Override functions are available to set various operating modes.
The program sequence of the control module includes a watchdog and a heartbeat function to monitor and maintain operation.
Operating modes
Temperature difference control
- Calculation of the supply air to room air temperature difference
- Discharge angle corresponds to characteristic
- Standard operating mode if temperature difference control has been configured
- No override functions
Variable operation
- Direct control of the discharge angle with a voltage signal (AI1) or with a network variable (nviManCntrl)
- Temperature difference is neglected
- Standard operating mode if variable operation has been configured
- No override functions
Cooling
- Override function, the discharge angle is reduced to the minimum
- Minimum angle is defined with SCPTminRnge (nvoActuatorPos)
- Set via DI1 or nviDI1_State
Isothermal operation
- Override function, the discharge angle is neutral
- Neutral position is defined with SCPTdischargeAirHeatingSetpoint
- Set via DI2 or nviDI2_State
Heating
- Override function, the discharge angle is increased to the maximum
- The maximum angle is defined with SCPTmaxRnge (nvoActuatorPos) and SCPTdischargeAitCoolingSetpoint
- Set via DI3 or nviDI3_State
Heating up
- Override function, the discharge angle is reduced to the minimum
- Set via DI4 or nviDI4_State
Inputs
Two analogue inputs
- Analogue inputs with configurable characteristic for signalling the supply air temperature and the room air temperature
- With variable operation: Analogue input for signalling the setpoint discharge angle
Four digital inputs
- Digital inputs for volt-free switches
- Override functions for variable operation, cooling, heating and isothermal operation
Outputs
One analogue output
- Analogue output with configurable characteristic for signalling to modulating actuators
Two digital outputs
- Digital outputs for signalling to heating/cooling actuators, 2-wire control (3-point)
Interface to the central BMS
- Actual operating values and fault messages of the control module are transferred via the network
- Supply air temperature, room air temperature, discharge angle
- Status of the digital inputs and voltage at each analogue input
LON-WA TDC Temperature Difference Control for Adjustable Air Terminal Devices with an Actuator
① LON-WA TDC control module
② Room temperature sensor, by others
③ Supply air temperature sensor, by others
④ Actuator, attached to the air terminal device
Specification Text
Control modules for signalling the temperature-based control input signal to adjustable air terminal devices with an actuator. For the connection of external temperature sensors for supply air and room air. A project-specific characteristic with two operating points to define the discharge angle based on the supply air to room air temperature difference is stored in the control module and cannot be deleted.
Ready-to-operate unit which consists of a PCB and a casing with knockouts. Control module electronics using a microprocessor, with configuration settings stored in EEPROM memory and hence safe in case of a power failure. Two analogue inputs, four volt-free digital inputs, one analogue output and two digital outputs as relay contacts.
The control modules include a LonWorks transceiver FTT-10A (free topology, twisted pair) and a service pin for LonWorks integration.
For the connection of modulating actuators to the analogue output, or of heating/cooling actuators (3-point) to the digital output.
Special characteristics
- Bespoke solutions since the characteristic can be adjusted
- Temperature values are transmitted as voltage signals or network variables
- Control input for actuators with a modulating signal (0 – 10 V DC) or 3-point (24 V AC)
- Override control functions for heating up, variable operation, heating, cooling and isothermal operation
Materials and surfaces
Technical data
- Supply voltage: 24 V AC ±15 %, 50/60 Hz
- Power rating: 3.5 VA
- Communication interface: LonWorks transceiver FTT-10A (free topology, twisted pair)
- Connection of LonWorks network: 4 terminals for cables with a cross section between 0.00012 and 0.00388 in², with reverse polarity protection
- IEC protection class: III (protective extra-low voltage)
- Protection level: IP 65
