Data Sheet for Product

ManualsBrandsSiemens ManualsAir ConditioningDESIGO RXA

CA2N3881en_02

2012-08-28

Siemens Building Technologies

881

DESIGO™ RXA

Non-communicating

room controllers

RXA20.1

RXA21.1

RXA22.1

For fan-coil systems

The RXA20.1, RXA21.1 and RXA22.1 room controllers are used for temperature

control in individual rooms.

 For 2-pipe or 4-pipe fan-coil systems, with or without changeover

 Control of AC 24 V PWM

thermic valve actuators, 3-position AC 24 V valve

and damper actuators, or electric heating coils

 Volt-free relay contacts for fan control and electric heating coils

 PI control

 AC 230 V operating voltage

1) PWM = pulse-width modulated

Use

The RXA20.1, RXA21.1 and RXA22.1 room controllers are optimised for control of fan-

coil systems in individual rooms.

They can be used for the following:

 RXA20.1: Single-speed automatic fan control, thermic valves

 RXA21.1: 3-speed automatic fan control, thermic or motorised valves

 RXA22.1: 3-speed automatic fan control, thermic valves

with built-in relay for electric re-heating

Summary of content (14 pages)

PAGE 1
3 881 DESIGO™ RXA Non-communicating room controllers RXA20.1 RXA21.1 RXA22.1 For fan-coil systems The RXA20.1, RXA21.1 and RXA22.1 room controllers are used for temperature control in individual rooms.
PAGE 2
Functions The controller application and the configuration of connected field devices are defined manually with DIP switches and a potentiometer. For a detailed description of functions, refer to the DESIGO RXA applications library, document CA2A3886. Types The RXA20.1, RXA21.1 and RXA22.1 room controllers differ only in the number of outputs available: Type RXA20.1/FC-01 RXA21.1/FC-02 RXA22.
PAGE 3
Design The RXA20.1, RXA21.1 and RXA22.1 room controllers consist of a housing base, a housing cover and the printed circuit board. The printed circuit board incorporates the connection terminals and the DIP switches used for configuration. The controllers also have a potentiometer for setpoint adjustment and testing, and a Service LED with different flashing patterns to indicate operational status and test states.
PAGE 4
Options for use of the labeling fields “Appl.” and “Loc.”: – Handwritten entry of location and the final application, or – Printed adhesive label Note Connection terminals STOP Caution To avoid incorrect wiring, terminals which can be connected to AC 230 V (supply and relay outputs) are physically separate from the other terminals. The cable restraints on the housing base must be used for the connections to terminals 19 … 28 (AC 230 V). The conductors must be secured with cable ties (see diagram).
PAGE 5
AC 24 V triac outputs The simultaneous load on outputs Y1 … Y4 must not exceed 9.5 VA. Example: Y1 (heating) 2 thermic valve actuators, type STP72E 6 W Y2 (cooling) 2 thermic valve actuators, type STP72E 6 W Y3, Y4 (outside air) Damper actuator 3.5 VA 3.5 VA The maximum load is 9.5 VA for the heating sequence and 9.5 VA for the cooling sequence. This is acceptable because the two sequences never operate at the same time.
PAGE 6
Commissioning The controller application and the configuration of the connected field devices are defined manually with DIP switches and the potentiometer. The Service LED provides information on power up and operational status. There is no special test for checking that the connected field devices match the DIP switch settings. Depending on the application, if the controller has insufficient information it switches to "Idle" mode (all outputs at zero) and the LED remains on continuously.
PAGE 7
Relay outputs Q14, Q24, Q34 External fuse Quantity Interfaces Cable connections Single cable lengths Housing protection standard Protection class Ambient conditions Standards and directives Relay type Contact rating with AC voltage Switching voltage Nominal current, resistive/inductive Making current 200 ms half-time Switching current at AC 19 V Contact rating with DC voltage Switching voltage Switching current at DC 5 V Switching capacity Inductive load L/R Q44 External fuse (essential) Relay type Ma
PAGE 8
Connection terminals and operator controls RXA20.1 00600 a 6 7 8 9 10 11 12 13 ON DIP S1...10 G Y2 G Y1 1 2 3 4 5 6 7 8 9 10 D3 5 D2 4 GND X2 M T 3 D1 2 B1 1 T 0...
PAGE 9
Connection terminals and operator controls RXA21.1 00601 a 6 7 8 9 10 11 12 13 DIP ON Y4 G Y3 Y2 G Y1 1 2 3 4 5 6 7 8 9 10 11 12 D3 5 D2 4 GND X2 M T 3 D1 2 B1 1 S 1...12 T 0...10 V M M AC 230 V QAX...
PAGE 10
Connection terminals and operator controls 3881Z02 6 7 8 9 10 11 12 13 ON DIP S1...10 G Y2 G Y1 1 2 3 4 5 6 7 8 9 10 D3 5 D2 4 GND M T 3 X2 2 B1 1 D1 RXA22.1 T 0...10 V AC 230 V QAX... 5(4) A 10 A 2 1 19 19 21 21 22 23 24 25 26 27 28 CP+ CP- M/S Q34 Q24 Q14 Q13 Q44 Q43 N.C.
PAGE 11
Connection diagrams Connecting the field devices, room units and supply voltage 3881Z03 N1 B1 1 M 2 X2 3 D1 4 GND 5 T B1 B1.1 T B2 B2.1 D1 D2 6 D2 D3 7 D3 Y1 8 Y1 G 9 Y2 10 Y3 11 G 12 Y4 13 M/S 14 CP– 15 CP+ 16 N 19 N 19 N L L 21 21 L Q13 25 Q14 26 1 Q24 27 2 Q34 28 3 N.C. 22 Q43 23 Q44 24 N1 N2...N4 B1, B2 B1.1, B2.1 X2.2 B3 D1, D2 D3 Y1, Y2 Y1.1, Y3.1 Y3.2 Q1 Q2 Q4 F1 X2.2 0...10 V GL M Y1.1 GL M Y3.1 Y2 Y3.
PAGE 12
STOP Caution  Fans connected to relay outputs Q14 … Q34 must not be operated in parallel. For parallel operation use cut-off relays or slave controllers.  At Q4 (max. resistive load 1.8 kW), use additional external fuses of max. 10 A to protect the pcb tracks. Note For information on the compatibility of the various field devices with the RXA20.1, RXA21.1 and RXA22.1 room controllers, refer to the relevant application description.
PAGE 13
Dimensions 00611 133,2 1,5 Dimensions in mm 3,3 35,3 Without terminal covers 3,9 1 62 With terminal covers 51,5 40,8 12 62 3,9 1 167 35,3 70210 112,4 107,8 00612 Drilling diagram 39 78 3,8 43,2 86,3 13/14 Siemens Building Technologies Non-communicating room controllers RXA20.1, RXA21.1, RXA22.
PAGE 14
/14  2001 - 2012 Siemens Building Technologies AG Siemens Building Technologies Non-communicating room controllers RXA20.1, RXA21.1, RXA22.