RTCb - Swegon

Swegon e.r.i.c. 2006, 22 November
www.swegon.com

RTCb

Room thermostat

FUNCTION

The RTC is used to regulate the temperature in rooms with a demand-controlled ventilation system. The room thermostat can control the air flow via a VAR air volume controller or active air diffuseras in the e.r.i.c. system that is used for cooling the room, or a radiator for heating. Can control the BLB mixing box for mixing warm and cold air in ventilation systems.

QUICK FACTS

Temperature sensor of type NTC
Adjustable setpoint value for room temperature
An LED indicates when in operation
Duct temperature sensor available as extra
Changeable outputs from 0-10 V to on/off
Connection for presence sensor
0-10 V outputs can be limited to allow for setting min./max. airflows or positions.

Figure 1. Suitable locations for the RTC room thermostat.

DESIGN

The RTC has a temperature sensor that is governed by the temperature in the surrounding air. On the printed circuit card the standard strapping is for 0-10 V output signals. This strapping can be changed to time proportional on/off control of each output, which could be suitable for controlling radiator heat. On the front is a setpoint dial with ±3 degree increments from a mid setting of 22°C. The RTC is also fitted with an LED that indicates the operational mode: red = heating, green = cooling, or off = switched off or in the dead band. Thanks to built-in intelligence the outputs are activated (on/off setting) once every 24 hours so that valves do not seize during the time of the year that they are not normally used. By connecting a presence detector the dead band can be extended so that there is no unnecessary cooling when the room is unoccupied. The RTC has limitations of the settings, that allow for setting of min/max air flows or positions.
The RTC can be configured for regulating air mixture with a dead band on one output. This is appropriate for controlling a type BLB mixing box. For particulars of the settings, see the Commissioning Instructions.

MATERIALS AND SURFACE TREATMENT

The enclosure is made of white ABS plastic.
RTCT 1 is made of brass and galvanized steel.

SPECIAL

The RTC can be adjusted by restrapping the printed circuit board, changing the outputs from a 0-10 V to an on/off function. Besides this standard product there are a number of advanced versions with more available settings for min/max limiting the 0-10 V output signal. For further information please contact your nearest sales office.

ACCESSORIES

Duct temperature sensor RTCT 1 for installation in an exhaust air duct.
Presence sensor KSO for extending the dead band between heating and cooling.
Hand terminal LUNAb T-CU

PLANNING

The RTC room thermostat is used in simple installations together with VAR, BLB or active air diffusers for regulating the room temperature. In premises where room RTCs are not desirable a duct temperature sensor accessory is available that can easily be wired to the thermostat’s connection block. The RCT is then attached directly to the VAR air flow regulator to minimize wiring. A presence sensor that increases the dead zone between heating and cooling from 1 to 4°C can be connected to the RTC.

INSTALLATION (See figure 1)

It is best to install the RTC between 1.5 and 2 m above the floor, on any wall in the room. It must not be subject to direct sunlight.

MAINTENANCE

Soiled products are to be cleaned by dusting or wiping with a damp cloth.

ENVIRONMENT/STANDARDS

The environmental product declaration and CE declaration are available from our website.
The RTCb is both ESD, LVD and S labelled.

Diagram 1.Functional diagram for comfort mode without presence sensor or activated presence sensor. Center position 22°C can be changed ±3°.

Diagram 2. Functional diagram in economy mode, presence sensor not activated. Center position 22°C can be changed ±3°.

Explanations of diagram 1 and 2

Heating with radiator
Neutral zone
Cooling with air
Set maximal out signal, cooling with air
Set minimal out signal, cooling with air

Diagram 3. Functional diagram for mixing control by means of the BLB wired to output C.

Explanations of diagram 3

Heating phase
Neutral zone
Cooling phase
Output signal for mixing control

Technical data

*Room thermostat RTC*
Ambient temperature:
Operation	+5 °C – 40 °C
Relative humidity	max. 90% RH, non condensing
Electrical data:
Supply voltage	24 V AC ±10%
Power consumption	1 VA
Outputs 0-10 V max load	10 mA
Outputs 24 V on/off max load	48 VA
Center position for temperature setting	22°C
P-band cooling increments	1.5 °C
P-band heating increments	1.0 °C
Dead band presence	1.0 °C
Dead band absence (with KSO)	4.0 °C

Enclosure:
Protection class	IP 30
Sensor, thermistor	1800 W at 25 °C
Accuracy, sensor, 0- till +35°C	±0.3 °C
Time constant	approx 7 min.

*Kanaltemperturgivare RTCT 1*
Ambient temperature:
Operation	0 °C – +50 °C
Relative humidity	max. 90% RH, non condensing
Electrical data:
Sensor, thermistor	10 kW at 25°C

Wiring diagram

Figure 2. Connections are to be made according to the wiring diagram for the product that the RTC is connected to.
A. = Cooling regulation
B. = Heating regulation

DIMENSIONS