Lennox LXRCC20 User guide

Providing indoor climate comfort
Application guide
LXRCC20-AGU-0509-E
LXRCC20 Remote control

Room Temperature
Controller
LXRCC20
for two-pipe fan coil units with electrical heater
Outputs for on / off valve actuator and electrical heater
Output for three-speed fan
Control depending on the room or return air temperature
Automatic heating / cooling changeover
Operating modes: normal, energy saving and frost protection mode or OFF
Operating mode changeover input for remote control
Selectable control parameters
Operating voltage AC 230 V
Use
Typical use:
• Control of the room temperature in individual rooms that are heated or cooled with
two-pipe fan coil units equipped with an electrical heater.
• For opening or closing a valve
• for switching an electrical heater
• for switching a three-speed fan.
1

Functions
The controller acquires the room temperature with its integrated sensor or external
room temperature sensor (QAA32) or external return air temperature sensor (QAH11.1)
– if used – and maintains the setpoint by delivering control commands to the 2-point-
valve. The switching differential can be 1 or 4 K in heating mode and 0.5 or 2 K in cool-
ing mode.
The fan is switched to the selected speed via control output Q1, Q2 or Q3.
When the function “Temperature-dependent fan control“ is activated (can be selected
with DIP switch no.1), the fan is switched on / off depending on the temperature, that is,
together with the valve.
It is switched off by
• leaving the heating or cooling sequence, provided the function “Temperature-
dependent fan control“ is activated, or
• manually changing to standby , provided plant conditions do not call for frost
protection mode, or
• activating an external operating mode changeover switch, provided plant conditions
do not call for energy saving or frost protection mode, or
• by turning the controller’s power supply off.
To avoid overtemperatures of the electrical heater or to prevent the thermal cutout from
responding, the fan will overrun for 30 seconds when the electrical heater is switched
off. During that period of time, the fan LED flashes.
In the event of failure, the RCC20 cannot protect the electric heater against overtem-
peratures. For this reason, the electric heater must be equipped with a separate safety
device (thermal cutout).
The heating or cooling valve receives the OPEN command via control output Y11 when
1. the measured room temperature lies by half the switching differential below the
setpoint (heating mode) or above the setpoint (cooling mode), and
2. the valve has been fully closed for more than one minute.
The heating or cooling valve receives the CLOSE command via control output Y11
when
1. the measured room temperature lies by half the switching differential above the
setpoint (heating mode) or below the setpoint (cooling mode), and
2. the valve has been fully open for more than one minute.
Note: control output Y12 delivers a control command which is inverted to the
control command at output Y11 and can be used for normally open valves
The RCC20 provides control either depending on to the measured room temperature or
depending on the fan coil unit’s return air temperature. Changeover is automatic if a
QAH11.1 cable temperature sensor is used.
The water temperature acquired by the changeover sensor (QAH11.1 + ARG86.3) is
used by the controller to switch from heating to cooling mode, or vice versa. When the
water temperature lies above 28 °C, the controller switches to heating mode, below
16 °C it switches to cooling mode. If, immediately after switching on, the water tempera-
ture lies between the 2 changeover points, the controller will start in heating mode. The
water temperature is measured at minute-intervals and the operational status updated.
Fan operation
Note
ON
Heating and cooling
mode
.
.
.
.
.
OFF
Return air tempera-
ture
Automatic
changeover
2

Heating mode Cooling mode Automatic changeover
1
0
SDH
Y11
W
3021D01
T [°C]
1
0
SDC
Y11
W
T [°C]
3021D02
CM
HM
M
T
W
[°C]
3021D03
16 28
CM Cooling mode TWWater temperature
HM Heating mode w Room temperature setpoint
M Operating mode Y11 Manipulated variable “Valve“
SDC Switching differential “Cooling“ T Room temperature
SDH Switching differential “Heating“
The task of the changeover sensor is to initiate the change from heating to cooling
mode even if the two-port valves are shut down for a longer period of time. To ensure
this function, the valves are opened for one minute at 2-hour intervals during off hours.
(Note: this function is not active when using thermal actuators).
In addition to hot water heating operation, the electrical heater receives an ON com-
mand via Y21 when
1. the measured room temperature is x ≤w −wD−½ SDH, and
2. the electrical heater has been switched off for more than one minute.
The OFF command for the electrical heater is given when
1. the measured room temperature is x ≥w −wD+½ SDH, and
2. the electrical heater has been switched on for more than one minute.
When two heating sequences are selected, the two outputs cannot be switched ON the
same time . Two outputs must be switched ON seperately with at least 1 minute delay.
In case of set-point change, the two heaters are allowed to switch OFF together.
For this operation, DIL switch no.8 must be set to ON (factory setting).
The electrical heater receives the ON command via control output Y21 when
1. the measured room temperature lies by half the switching differential below the
adjusted setpoint, and
2. the electrical heater has been switched off for more than one minute.
The OFF command for the electrical heater is given when
1. the measured room temperature lies by half the switching differential above the
adjusted setpoint, and
2. the electrical heater has been switched on for more than one minute.
Heating mode (hot water plus electric) Cooling mode with optional electric heating sequence
(DIP switch no.8 = ON)
wD
1
0
1
½ SDH ½ SDH
½ SDH ½ SDH
w
Y11
Y21
3022D01
T [°C]
Xdz
½ SDH ½ SDH
1
0
1½ SDC½ SDC
Y11
Y
21
3022D04
w
T [°C]
Purging function
Electric heating op-
eration, active in the
heating sequence
Electric heating op-
eration, active in the
cooling sequence
3

Cooling mode (chilled water)
(DIP switch no.8 = OFF)
½ SDC
1
0
½ SDC
w
Y
11
3022D02
T [°C]
T[°C] Room temperature w Room temperature setpoint
Y11 Manipulated variable«Valve» Y21 Manipulated variable «Electric heating»
SDH Switching differential ”Heating” wDSetpoint differential
Xdz Dead zone SDC Switching differential ”Cooling”
The room temperature setpoint can be limited in increments of 1 K by making use of
the minimum and maximum limitation facility. Arbitrary setpoint readjustments can thus
be presented.
Operating modes
The following operating modes are available:
Heating or cooling mode with automatic changeover and with manually selected fan
speed III, II or I. In normal operation, the controller maintains the adjusted setpoint.
The frost protection function is activated only when DIP switch no.4 is set to OFF.
Frost protection mode can be activated either
• by manually switching to standby .
• by activating the external operating mode changeover switch, provided
DIP switch 2 is set to OFF
If the room temperature falls below 8 °C, the controller will automatically switch to frost
protection mode. In that case, the heating valve opens and the fan operates at the se-
lected speed. If the selector is in position standby , the fan will operate at speed I.
The room temperature is maintained at a setpoint of 8 °C and the setpoint adjusted by
the user will be ignored.
If frost protection operation is locked (DIP switch no. 4 in position ON), standby is
locked also, which means that the controller will not switch to standby but to OFF.
In frost protection mode, the electrical heater is always enabled, independent of the
position of DIL switch no.8 ( behaviour of electrical heater in cooling mode).
In energy saving mode, the setpoint of heating is 16°C and the setpoint of cooling
28 °C, independent of the position of the setpoint knob. This operating mode will be
activated when input D1 for operating mode changeover is active and DIP switch no.2
is set to ON.
A changeover switch can be connected to status input D1–GND. When the switch
closes its contact (caused by an open window, for instance), the operating mode will
change from normal operation to energy saving mode (provided DIP switch no.2 is set
to ON), or from normal operation to standby (provided DIP switch no.2 is set to OFF). If
the room temperature falls below 8 °C and if DIP switch no.4 is set to OFF, frost protec-
tion mode will become active.
The operating action of the switch (N.C. or N.O) can be selected.
Ordering
When ordering, please give name and type reference.
The QAH11.1 temperature sensor (can be used as a return air temperature or change-
over sensor), the changeover mounting kit and the zone valve are to be ordered as
separate items.
Energy saver
Normal operation
Frost protection mode
Note
Energy saving mode
Operating mode
changeover switch
4

Equipment combinations
Type of unit Type reference Data sheet
Temperature sensor QAH11.1 1840
Room sensor QAA32 1747
Changeover mounting kit ARG86.3 1840
Motoric on/off actuator SFA21... 4863
Thermal actuator (for radiator valve) STA21... 4893
Thermal actuator (for small valve 2,5 mm) STP21... 4878
Mechanical design
The unit consists of two parts:
• A plastic housing which accommodates the electronics, the operating elements and
the built-in room temperature sensor
• A mounting base
The housing engages in the mounting base and snaps on.
The base carries the screw terminals; the DIP switches are located at the rear of the
housing.
3021Z01
256 13 4
1. Operating mode selector
(standby, heating or cooling mode with manual selection of fan speed)
2 LEDs for indicating heating mode, cooling mode and fan operation
3 Setting facility for minimum setpoint limitation (in increments of 1 K)
4 Setting facility for maximum setpoint limitation (in increments of 1 K)
5 Room temperature setpoint knob
6 Set of DIP switches
DIP switch no. Meaning Position ON Position OFF
1 Fan control Fan control is temperature-
dependent in all operating
modes
Fan control in normal operation is tem-
perature-independent 1)
2 Operating mode change-
over via an external switch
Changeover between normal
operation and energy saving
mode
Changeover between normal operation
and standby 1)
3 Operating action of switch
for external operating
mode changeover
Changeover activated when
contact of switch is closed
(N.O.) 1)
Changeover activated when contact of
switch is open (N.C.)
4 Standby Frost protection function not
enabled
Frost protection function enabled 1)
5 Switching differential 1 K in heating mode 1)
0.5 K in cooing mode 1)
4 K in heating mode
2 K in cooling mode
Setting and operating
elements
Legend
5

6 Dead zone in normal op-
eration
2 K1) 5 K
7 Setpoint differential 2 K1) 4 K
8 Electrical heater Active in cooling mode1) Inactive in cooling mode
1) Factory setting
Accessories
Description Type reference
Adapter plate 120 x 120 mm for 4“ x 4“ conduit boxes ARG70
Adapter plate 96 x 120 mm for 2“ x 4“ conduit boxes ARG70.1
Adapter plate for surface wiring 112x130 mm ARG70.2
Engineering notes
In system without automatic changeover, the temperature sensor can be replaced by
an external switch for manual changeover.
In system with continuous heating operation, no sensor will be connected to the control-
ler’s input.
With continuous cooling operation, the controller input (B2–M) must be bridged.
Mounting location: on a wall or inside the fan coil unit. Not in niches or bookshelves, not
behind curtains, above or near heat sources and not exposed to direct solar radiation.
Mounting height is about 1.5 m above the floor. The connecting wires can be run to the
controller from a recessed conduit box.
Check the settings of the DIL switches no.1 through no.8 and change them, if required.
It setpoint limitation is required, use the minimum and maximum limitation facility (en-
ergy saver).
After applying power, the controller makes a reset during which the fan LED flashes
indicating that the reset has been correctly made. This takes about 3 seconds. Then,
the LED stops flashing and the controller will be ready to operate.
• Prior to fitting the changeover sensor, thermal conductive paste must be applied to
the location on the pipe where the sensor placed
• The cables used must satisfy the insulation requirements with regard to mains poten-
tial
• Sensor inputs B1–M and B2–M carry mains potential. If the sensor’s cables must be
extended, the cables used must be suited for mains voltage
The controller is supplied with Mounting Instructions.
Mounting, installation
and commissioning
notes
6

Technical data
Operating voltage AC 230 V +10/-15 %
Frequency 50/60 Hz
Power consumption max. 6 VA
Control outputs Q1, Q2, Q3
Rating
AC 230 V
max. 600 VA
Control output Y11 (N.O. contact)
Rating
AC 230 V
max. 300 VA
Control output Y12 (N.C. contact)
Rating
AC 230 V
max. 300 VA
Control output Y21 (N.O. contact)
Rating
AC 230 V
max. 1250 VA
Signal input B1 for return air sensor QAH11.1, Safety class II
NTC resistor 3kΩat 25°C
Signal input B2 for changeover-sensor QAH11.1, Safety class II
NTC resistor 3kΩat 25°C
Status input D1 and GND
Contact sensing
Insulation against mains
SELV DC 6-15V / 3-6 mA
4 kV, extra insulation
Perm. cable length with copper cable 1.5 mm2
for connection to terminals B1, B2 and D1 80 m
Setpoint setting range 8...30 °C
Max. control deviation at 25 °C max. ±0.7 K
Switching differential in heating mode SDH (select-
able)
1 K or 4 K
Switching differential in cooling mode SDC (select-
able)
0.5 K or 2 K
Dead zone Xdz in normal operation 2 K or 5 K
Setpoint «Energy saving mode », heating 16 °C
Setpoint « Energy saving mode », cooling 28 °C
Setpoint «Standby » 8 °C
Operation
Climatic conditions
Temperature
Humidity
to IEC 721-3-3
class 3K5
0…+50 °C
<95 % r.h.
Transport
Climatic conditions
Temperature
Humidity
Mechanical conditions
to IEC 721-3-2
class 2K3
-25…+70 °C
<95 % r. h..
class 2M2
Storage
Climatic conditions
Temperature
Humidity
to IEC 721-3-1
class 1K3
–25…+70 °C
<95 % r. h..
conformity to
EMC directive
Low voltage directive
89/336/EEC
73/23/EEC and 93/68/EEC
N474 C-Tick conformity to
EMC emission standard
AS/NSZ 4251.1:1994
Product standards
Automatic electrical controls for household and
similar use
EN 60 730 – 1 and
EN 60 730 – 2 - 9
Power supply
Operational data
Environmental conditions
Norms and standards
7

Electromagnetic compatibility
Emissions
Immunity
EN 50 081-1
EN 50 082-1
Safety class II to EN 60 730
Pollution class normal
Degree of protection of housing IP30 to EN 60 529
Connection terminals Use solid wires or prepared
stranded wires.
2 x 0.4-1.5 mm2or 1 x 2.5 mm2
Weight 0.23 kg
Colour of housing front white, NCS S 0502-G (RAL9003)
Connection terminals
L
N
B1 M B2 D1GND
Q1 Q2 Q3 Y12 N Y21
3022G01
Y11
SELV
L, N Operating voltage AC 230 V
B1 Status input “Return air
tempera ture sensor”
M Measuring neutral “Return air
temperature sensor and change
over sensor”
B2 Status input “Changeover sensor”
D1, GND Status input for potential-free operating
mode changeover switch
(operating action can be selected)
Q1 Control output “Fan speed I” AC 230 V
Q2 Control output “Fan speed II” AC 230 V
Q3 Control output “Fan speed III” AC 230 V
Y11 Control output “Valve” AC 230 V
(N.O. contact, for N.C. valves)
Y12 Control output “Valve” AC 230 V
(N.C. contact, for N.O. valves)
Y21 Control output “Electric heating” AC 230 V
Connection diagram
L
LB1 M B2 D1 GND
Q1 Q2 Q3 Y11 N
N
N
IIIIII
N
B1 B2 S1
N1
M1 E1
3022A01
Y12 Y21
Y1
B1 Return air temperature sensor (QAH11.1)
B2 Changeover sensor
(QAH11.1 temperature sensor + ARG863.3
changeover mounting kit)
E1 Electrical heater
M1 Three-speed fan
N1 RCC20 room temperature controller
S1 External operating mode changeover switch
Y1 MVE..., MXE... zone valve
Dimensions
96,6
114,15
42,8
3021M01
90
4
4
3021M02
28 28
2828
26 30
3530
11,8
104
4
General
Unit/baseplate
8

 + 32 3 633 3045
 [email protected]
 [phone]
 [email protected]
 + 49 69 42 09 79 0
 [email protected]
 + 31 332 471 800
 [email protected]
 [phone]
 [email protected]
 [phone]
 [email protected]
 [phone]
 [email protected]
 [phone]
 [email protected]
 [phone]
 [email protected]
 [phone]
 [email protected]
 [phone]
 [email protected]
 +33.4.72.23.20.00
 [email protected]
LXRCC20-AGU-0509-E
Due to Lennox’s ongoing commitment to quality, the Specifications, Ratings and Dimensions are subject
to change without notice and without incurring liability.
Improper installation, adjustment, alteration, service or maintenance can cause property damage or
personal injury.
Installation and service must be performed by a qualified installer and servicing agency
Direct Sales Offices:
LENNOX DISTRIBUTION
Distributors and Agents
Algeria, Austria, Belarus, Botswana, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, Georgia, Greece,
Hungary, Israel, Italy, Kazakhstan, Latvia, Lebanon, Lithuania, Morocco, Near East, Norway, Romania, Serbia, Slovenia,
Sweden, Switzerland, Tunisia, Turkey
BELGIUM AND LUXEMBOURG
FRANCE
GERMANY
NETHERLANDS
POLAND
PORTUGAL
RUSSIA
SLOVAKIA
SPAIN
UKRAINE
UNITED KINGDOM AND IRELAND