R7426B,C
MicroniK 200
Fig. 1. Temperature controller
TEMPERATURE CONTROLLER
WITH REAL-TIME CLOCK
SPECIFICATION DATA
GENERAL
The R7426B,C temperature controllers cover all space and/or
discharge air temperature applications within the specified
control range of 0...50°C (LOw range) requiring sequence
operation of heating, mixed air damper or energy recovery
system and cooling with optional outside air temperature
compensation reset of the main setpoint. The controllers can
be configured to perform space or discharge air or spacedischarge air temperature cascade control with limit control.
For special higher temperature control applications, the
control range 0...130C (HI range) can be selected.
FEATURES
Weekly time schedule with up to six switching points
per day
Automatic daylight saving time change
Four different operating modes: Comfort, Standby,
Night, and OFF
Yearly holiday programming in advance
Three types of holiday schedules
Self-adaptive optimum start program for room control
system
Night cycle program
Fig. 2. LC Display
Order Numbers
Order-No. Controller Description
R7426B2012 Temperature controller with integrated
real time clock (RTC), Plant/System
ON/OFF output, and three 3-position
floating outputs. The controller offers the
choice of selectable different output
sequence operations and output signals
suitable to drive solid-state relays or step
relays.
R7426C2010 Temperature controller with integrated
real time clock (RTC), Plant/System
ON/OFF output, and three analog
outputs. The controller offers selection of
different output sequence operations.
EN0B-0301GE51 R0104
R7426B,C TEMPERATURE CONTROLLER
TECHNICAL DATA
General
Electronic 8-bit microcontroller, 10-bit A/D converter, EEPROM, and LC
display
Power supply 24 Vac +10...-15%, 50/60 Hz
Power consumption 3 VA + Actuator power requirements
Control range 0...50°C
Temperature
Inputs
Sensor type
1)
CPA/SPA-Input
Battery
T1 Main temperature sensor
T2 Cascade temperature sensor
T3 Compensation temperature sensor
Automatic identification of sensor type Temperature range Characteristics
Pt 1000
BALCO 500
NTC 20kτ -30....+85C / -30....+130C
1)
CPATYP 0
CPATYP 1 (953...1053 τ) CPA: 5 K
CPATYP 2 (0...100 kτ) CPA: 5 K
Type CR2032 (life time 8 years)
accuracy 0.5 K
excluding
sensor
2)
-30....+130C 1000 τ at 0C
-30....+130C 500 τ at 23.3C
1)
20 kτ at 25C
CPA/SPA range Sensor & CPA/SPA types
CPA: 5 K
internal
T7412B1016 (Pt 1000)
T7412B1057 (Pt 1000)
T7412C1030 (Pt 1000)
T7412B1008 (NTC 20kτ)
T7412C1006 (NTC 20kτ)
CPATYP 3 (10...20 kτ) SPA: 15...30C
T7412B1024 (BALCO 500)
T7412B1040 (Pt 1000)
CPATYP 4 (0...10 kτ) CPA: 5 K
HCW 23 (setpoint wheel
printed with +/- 5 K)
CPATYP 5 (0...100 kτ) SPA: 15...30C
CPATYP 6 (0...100 kτ) SPA: 0...50C or 0...130C
Analog input Humidity deviation (X
) -5...+5 Vdc, 200 mV / %rh
wrh
43193982-001
43193982-001
Digital inputs Mode Potential free contact
Occupancy unoccupied
occupied
Freeze protection input freeze protection operation
normal operation
open > 40 kτ
closed < 100 τ
open > 40 kτ
closed < 100 τ
Outputs ON/OFF output OFF / ON
TRIAC outputs
Floating
2, 3, 4, 6 or 15-stage
ON (24 Vac) / OFF (0 Vac)
Pulse-width modulation
1)
1)
max. load
450 mA at
24 Vac per
1)
0...100%
output
based on run time
Analog outputs on controller R7426C Control range
full range 0...12 Vdc
1)
0/2...10 Vdc (0...100%)
max. load
1.2 mA at
12 Vdc
Ambient limits
Operating temperature
Transport and storage temperature
0...50°C (0...122F
)
-35...+70°C (-31...+158F
)
Relative humidity 5...95%rh non-condensing
Safety
Protection class II as per EN60730-1
Protection standard IP30 or IP40 (front panel mounting) as per EN60529
Housing
Dimensions (H x W x D) 105 x 152 x 37 mm
Weight 250 g
Mounting Front door, back panel, wall, or rail
Connections Connection terminal terminals max. 1 x 1.5 mm
1)
Selectable
2)
same sensor type must be used for T1, T2, and T3
2
EN0B-0301GE51 R0104 2
CONTROL AND CONFIGURATION PARAMETER
R7426B,C TEMPERATURE CONTROLLER
Control Parameter Setting
Parameter Description
No. Name
Low High Default
Resolution
Unit
P.01 W1 Main setpoint for input T1 0 50 21 0.5 C
P.02 Wlim Limit setpoint (low or high) for input T2 5 50 16 1 C
P.03 Wcomp Compensation changeover point for input T3 -5 40 20 1 C
P.04 Wi Winter compensation authority -350 +350 0 2 %
P.05 Su Summer compensation authority -100 +100 0 1 %
P.06 Wcas Submaster or cascade setpoint OFF, 0 50 20 0.5 C
P.07 Rcas Cascade reset span adjustment 0 40 10 0.5 K
P.08 Xp1 Throttling range (main control loop) T1 0.5 40 2 0.5 K
P.09 Xp2 Throttling range (cascade control loop) T2 0.5 40 10 0.5 K
P.10 Xpc Cooling throttling range for sequence control OFF, 1 40 3 0.5 K
P.11 Xph Heating throttling range for sequence control 1 40 6 0.5 K
P.12 tr1
P.13 tr2
1)
Reset time (main control loop) T1 OFF, 20 s 20min OFF 10/0.5 sec/min
1)
Reset time (cascade control loop) T2 OFF, 20 s 20min OFF 10/0.5 sec/min
P.14 MINPOS Minimal pos. for air damper actuators 0 50 20 1 %
P.15 Ystart Start point for mid range shift of output Y1 -20 +20 0 0.5 K
P.16 SOFFS Offset of main setpoint in Standby mode 0 10 2 0.1 K
P.17 T1Cal Calibration of temperature sensor T1 -20 +20 0 0.1 K
P.18 T2Cal Calibration of temperature sensor T2 -20 +20 0 0.1 K
P.19 T3Cal Calibration of temperature sensor T3 -20 +20 0 0.1 K
P.20 RetOffs Return air offset to simulate exhaust air cond. OFF, 0 5 OFF 0.1 K
P.21 RuntimeY1 Actuator run time for output Y1 6 180 60 1 sec
P.22 RuntimeY3 Actuator run time for output Y3 6 180 60 1 sec
P.23 RuntimeY2 Actuator run time for output Y2 6 180 60 1 sec
P.24 NightLow Night low limit against temperature extremes OFF, 8 19 OFF 1 C
P.25 NightHigh Night high limit against temperature extremes OFF, 21 40 OFF 1 C
P.26 NOFFS Offset of main setpoint in Night mode 0 30 5 0.1 K
Config. Parameter
Values Default Unit
No. Name
C.01 DIR/REVY1 Dir
C.02 DIR/REVY3 Dir, Rev (R7426C, only) Dir
C.03 DIR/REVY2 Dir
C.04 Ctrltyp
2)
Lo = 0...50°C (factory preset), Hi1 = 0...130°C, Hi2 = 0...130°C
0 = internal (default), 1 = 5 K (953...1053 τ), 2 = 5 K (0 τ...100kτ),
C.05 CPATYP
3 = 15 … 30C (10...20 kτ), 4 = 5 K (0...10 kτ),
0
5 = 15 … 30C (0...100 kτ), 6 = 0...50C or 0...130C (0...100 kτ)
C.06 YRange 0 = 2 … 10 Vdc , 1 = 0 … 10 Vdc (R7426C, only) 1
C.08 Y1Mode 4
C.09 Y3Mode 4
C.10 Y2Mode
0= floating, 1= 2 stage ON/OFF, 2= 3 stage ON/OFF, 3 = pwm, 4 = unconfig.
(safe state is configured prior to controller's start-up) (R7426B, only)
4
0: Y1 = D, Y2 = C, Y3 = H 1: Y3/2/1 = H or C
C.11 YMode
2: Y3/1 = H, Y2 = C 3: Y3/1 = C, Y2 = H
0
4: Y1 = 2Pos D, Y2 = C, Y3 = H 5: Y3/1 = 15H, Y2 = C
C.12 T2ext 0 = T2 installed 1 = T1 signal used for T2 0
C.13 LimTyp 0 = Low limit 1 = High limit 0
C.14 Senstyp 0 = Auto detection 1 = NTC sensor type 0
C.15 Y1CTRF
Output Y1 used for: 0 = mixed air damper
1= energy recovery
0
C.16 AddHour Adjusts the month for winter/summer time change: 0 (disabled) = Min. 12 = Max. 3 month
C.17 SubHour Adjusts the month for summer/winter time change: 0 (disabled) = Min. 12 = Max. 10 month
3 EN0B-0301GE51 R0104
R7426B,C TEMPERATURE CONTROLLER
Config. Parameter
Values Default Unit
No. Name
C.18 PSTG_H3)Prestart gradient for heating: 0 (disabled) = Min. 2 = Max. 0 K/min
C.19 PSTG_C3)Prestart gradient for cooling: 0 (disabled) = Min. 2 = Max 0 K/min
C.20 tvd Use damper before comfort time: 0 (normal control) = Min. 90 = Max. 15 min
C.21
C.22
C.23
1)
for tr > 2 min resolution = 0.5 min, for tr < 2 min resolution = 10 sec
2)
actual value will not be changed during reset to default parameter
3)
can be overwritten by controller for self-adaption purposes, resolution = 0.01 K/min
FUNCTIONS
Real-Time Clock
The time clock performs automatic change of the controller
mode to OFF, Night, Standby, or Comfort in accordance with
the programmed time schedule. In Standby or Night mode,
the SOFFS or NOFFS is added (cooling) to and subtracted
(heating) from the calculated control point. Schedules for one
Adapt
2)
Adr
DefProg
Optimum Start Self Adaption speed: 0 = Min. 100 = Max. 50 %
Serial communication address: 0 = Min. 255 = Max. 254
0 = No Default programming 1 = Initiates Default programming 0
APPLICATION
The R7426B,C controllers can be used for sequence control
applications of heating, mixed air damper or energy recovery
system, and cooling.
NOTE: All diagrams show proportional control action, only.
If P+I control is in operation, the slopes for heating
and cooling are not defined.
week and up to six switching points per day can be programmed in advance and repeated week after week. In
addition, three different holiday schedule types H1, H2 and
H3 can be programmed. One of these holiday types can be
assigned to each holiday date of the year (01.01. ... 31.12.).
Holiday type H1 and H2 is valid only for this specific day and
is reset to normal time schedule at midnight of that day. H3 is
valid for every year and repeated year after year for fixed
holiday dates. H1 can be programmed to be in OFF mode
the whole day and H2 to be ON for a short period of time on
the last day of a longer holiday period to preheat or precool
the space in advance before the first occupied day.
Temperature Sequence Control with Heating,
Mixed Air Dampers, and Cooling
This application will be active with the R7426B,C controllers
when T2 is not connected. It can be used for sequence
control of a heating valve, a mixed air damper, and a cooling
valve.
The characteristic of each output on the R7426C controller
can be selected via the control parameters DIR/REVx
(x = Y1, Y2, or Y3). The diagram shows Dir characteristic for
all outputs.
Optimum Start Program
The optimum start program’s objective is to minimize total
energy consumption by calculating in room control applications the start time for heating and cooling mode which will
bring its respective space temperature to the boundary of the
comfort zone at the time of occupancy start. The program will
start the ventilation system at the calculated start time with
forced return air recirculation mixed air damper position or full
energy recovery valve position to minimize energy consumption during the start-up period. At a programmable time
before occupancy start, the controller will switch the output
signal Y1 to normal and will supply fresh air to the space in
mixed air applications. The optimum start program uses
historical data for self-adaptive adjustment.
Night Cycle Program
The night cycle program offers not only energy conservation,
but also the ability to assign OFF mode night low or high
limits with 1K hysteresis for the protection of a space and its
Within the range Xp1, the damper signal is controlled as
shown in the diagram below. If no cooling actuator is available, the control parameter Xpc can be set to OFF and the
damper output is maintained at 100% above control point
(CTRP1).
If the damper output should be decreased to MINPOS level
above control point (CTRP1) as shown in the diagram, the
control parameter Xpc has to be adjusted to any value
between 1 and 40 K, also if no cooling actuator is available.
Y[%]
100
MINPOS
0
Y3
Heating
Xph
Damper
Y1
CTRPH
1/4 Xp1 if Xpc = Off
Cooling
Xp1
CTRPC
Xpc
CTRP1
Y2
if Xpc = Off
Xwh / Xwc
contents against temperature extremes. It automatically
cycles between the user selected upper and lower limits and
turns on full heating or cooling whenever the limits are
reached.
NOTE: If the R7426B controller with floating output is used
for mixed air damper control, you must ensure that
the output load of maximum 450 mA is not
exceeded.
Xwd
/
T2
EN0B-0301GE51 R0104 4
R7426B,C TEMPERATURE CONTROLLER
Temperature Sequence Control with Heating,
Energy Recovery System, and Cooling
For applications with energy recovery system (ERS), the configuration parameter Y1CTRF has to be set to 1 to perform a
reverse acting Y1 output. The adjustment MINPOS is inactive
in this configuration and the control parameter Xpc has to be
set to OFF if the output should be maintained at 0% above
the control point (CTRP1) for summer operation.
Within the range Xp1, the energy recovery system is controlled as shown in the diagram below. With the R7426C
controller, a rotary energy recovery wheel can also be
controlled instead of a valve if the output signal of 0...10 Vdc
or 2...10 Vdc is suitable to control the rotation speed of this
device.
Y[%]
100
0
Heating
Y3
Xph Xp1
ERS
Y1
CTRP1CTRPH
1/4 Xp1
000
Cooling
Y2
Xpc=off
Xwh/Xwc/Xwd
CTRPC
Xpc
Temperature Cascade Control with Heating,
Mixed Air Dampers, and Cooling
This application will be active with the R7426B,C controllers if
temperature sensor T2 is connected and the control parameter W
for sequence control of a heating valve, a mixed air damper,
and a cooling valve.
The controllers provide cascade control as shown below:
Xp1/2
Offs
Offs
Xp1/2
is set to any value other than OFF. It can be used
cas
T1
C
MASTER
CTRP1
T1
Low limit of CTRP2 is performed if control parameter
LimTyp = 0 and high limit of CTRP2 is performed if control
parameter LimTyp = 1.
Within the range Xp2, the damper signal is controlled as
shown in the diagram below. If no cooling actuator is available, the control parameter Xpc can be set to OFF. If control
parameter Xpc = OFF, the cooling signal is set to 0% and the
damper output is maintained at 100 % above control point
(CTRP2).
Y[%]
100
MINPOS
0
Y3
Heating
Xph
Damper
Y1
CTRPH
1/4 Xp2 if Xpc = Off
Cooling
Xp2
CTRPC
Xpc
CTRP2
Y2
if Xpc = Off
Xwh / Xwc
NOTE: If the R7426B controller with floating output is used
for mixed air damper control, you must ensure that
the output load of maximum 450 mA is not
exceeded.
Temperature Cascade Control with Heating,
Energy Recovery System, and Cooling
For applications with energy recovery system (ERS) the
configuration parameter Y1CTRF has to be set to 1 to
perform a reverse acting Y1 output. The adjustment MINPOS
is inactive in this configuration and the control parameter Xpc
must be set to OFF if the outputs Y1 and Y2 should be
maintained at 0% above the control point (CTRP2) for
summer operation.
Within the range Xp2, the energy recovery system is controlled as shown in the diagram below. In the case of the
R7426C controller, a rotary energy recovery wheel can also
be controlled instead of a valve if the output signal of
0...10 Vdc or 2...10 Vdc is suitable for controlling the rotation
speed of this device.
Y[%]
100
Heating
Y3
ERS
Y1
1/4 Xp2
Cooling
Y2
Xwd
/
T2
0
CTRP2
W
R
cas
R
cas
lim
W
cas
W
lim
Offs = SOFFS for Standby Mode
0 for Comfort Mode
NOFFS for Night Mode
SUBMASTER
X Master
w
for
LimTyp=1
for
LimTyp=0
0
Xph Xp2
000
CTRP2CTRPH
CTRPC
Xpc=off
Xwh/Xwc/Xwd
Xpc
T2
Economizer Modes
The economizer modes are suitable for installations where
the main temperature sensor (T1) is installed in the exhaust
air or in the room with a constant offset between room and
X Master
0
w
exhaust air conditions. The offset value is programmable
within 0...5 K with the control parameter RetOffs which will
be added to the actual measured room temperature value to
simulate exhaust air conditions.
5 EN0B-0301GE51 R0104
R7426B,C TEMPERATURE CONTROLLER
p
The economizer mode is disabled if the value of the control
parameter RetOffs is programmed to OFF, or if no outdoor
air temperature sensor is connected.
By comparing the outside air condition with the exhaust air
condition, the output for Y1 on the controller operates as
follows:
Mixed Air Dampers
RetOffs OFF; Y1CTRF = 0
AIR CONDITION Y1
Outside air temperature >
MINPOS
Exhaust air temperature
Outside air temperature <
Exhaust air temperature
Included in heating
sequence control (direct
acting)
Y[%]
100
MINPOS
0
Damper
Y3 Y2
Heating
Xph
Y1
CTRPH
T
OA
T1+RetOffs
< T
EA
1K
CTRP1
CTRP2
Xp1
Xp2
TOA > T
CTRPC
EA
Cooling
Xpc
Xwh / Xwc
T1/T2
A fixed hysteresis of 1K is used, to switch between MINPOS
and actual Y1 signal.
Energy Recovery System
RetOffs OFF; Y1CTRF = 1
AIR CONDITION Y1
Outside air temperature >
Exhaust air temperature
Outside air temperature <
Exhaust air temperature
100%
Energy Recovery System
included in heating
sequence control.
MINPOS is not active.
CONTROLLER FUNCTIONS
Outside Air Temperature Compensation
Outside air temperature compensation is performed when T3
is connected. The control parameter W
pensation changeover point for summer and winter compensation. The degree of summer and winter compensation is
defined by control parameters Wi and Su.
Winter compensation is performed if temperature
T3 < W
perature T3 > W
. Summer compensation is performed if tem-
comp
W1
compensated
C
W1
comp
.
Wi Su
W
comp
Smoothing Filter for Outside Air Temperature Input
A smoothing filter for the outside air temperature input T3 is
incorporated to eliminate sudden temperature variations. This
provides more stable operation of the control system. This
function will work only if the controller parameters have never
been changed by means of the PC tool.
Occupied/Unoccupied Function (SOFFS)
A potential free contact can be used between terminals 1 and
4 to switch the controller between occupied (contact closed)
or unoccupied (contact open) mode. The input is active
during Comfort and Standby mode.
In occupied mode, the temperature set point W1 is used for
the control point calculation. In unoccupied mode, the
SOFFS parameter value is added (cooling) to and subtracted
(heating) from the calculated control point for cooling and
heating.
The diagram below shows the occupied/unoccupied function
for sequence control.
defines the com-
comp
Positive
Negative
T3
C
Y
Y[%]
100
0
Energy
Recovery
Y3
Heating
Xph
Y1
CTRPH
TOA < T
CTRP1
CTRP2
Xp1
Xp2
T1+RetOffs
TOA > T
EA
1K
CTRPC
EA
Cooling
Xpc
Y2
Xwh / Xwc
T1/T2
%
100
unoccupied
occupied
SOFFS
Xph
CTRPH CTRPC
SOFFS
Xpc
CT
A fixed hysteresis of 1 K is used to switch between 0%
osition and actual Y1 signal.
Freeze Protection
If the contact connected to the freeze protection input is
open, the heating valve (Y3) will be driven into the fully open
position. The final control devices operated by the outputs
(Y1 and Y2) will be driven in the closed position.
EN0B-0301GE51 R0104 6
R7426B,C TEMPERATURE CONTROLLER
In the case of controllers with RTC, the ON/OFF output will
be switched off.
A closed contact performs a frost recovery:
Conditions of
Outdoor Temp. T3
> 6C or T3 not
connected
Frost Recovery
Main temperature control
Setpoint W1 is temporarily raised by
< 6C
Xp1 and linearly decreased to its
normal value over approx. 10min.
Freeze protection operation has the highest priority over all
other control operations.
Dehumidification Control by Humidity
Deviation Input
Dehumidification control can also be performed using a
humidity controller. The deviation input signal X
from the humidity controller is compared with the cooling
deviation signal of the temperature control (X
with the highest cooling demand is used to control the
cooling output Y2.
received
w rh
). The signal
wc
Sequence control with two outputs for heating and one
output for cooling (YMode = 2)
Y[%]
100
Y3
Y1
0
OAIC
Heating
Xph
Y2
Cooling
Xpc
Xw
T
Sequence control with one output for heating and two
outputs for cooling (YMode = 3)
Y[%]
100
Y2 / OAIH
0
Heating
Y3
Cooling
OAIC
Y1
Xw
XpcXph
T
OUTPUT SEQUENCE OPERATION
The controllers are supplied from the factory configured for
sequence operation of heating, mixed air, and cooling
control.
NOTE: If a control range of 0...130 °F (C.04 = 1) is
selected, then only multi-stage heating (Ymode = 1)
is applicable.
The output sequence operation can be configured for the
following control applications in accordance with the
parameter setting Y1CTRF or YMode:
Sequence control for cooling with three outputs
(Y1CTRF = 0 and YMode = 1)
Y[%]
100
Y3
0
throttling range
Sequence control for heating with three outputs
(Y1CTRF = 1 and YMode = 1)
Y[%]
100
0
OAID
Y1
throttling range
Y2
Y2
OAID
Y1
Xw
Y3
Xw
OUTPUT FUNCTIONS
The R7426B controllers provide a choice of output signals
suitable for operating a range of final control devices
according to the parameter setting of YMode and YxMode
(x = 1, 2, or 3) control parameters.
3-position Output for Valve or Damper Actuators
(floating mode)
The controller converts the deviation signal to a proportional
output pulse which drives the actuators depending on the
Runtimex (x = Y1, Y2, or Y3) parameter value.
Parameter setting for Heating / Cooling Control Outputs :
YMode = 0, 1, 2 or 3; YxMode (x = 1, 2, or 3) = 0.
on
off
out1
close open
stop
An automatic synchronization function ensures correct
positioning of the actuators. This is performed by running all
actuators to the closed position periodically. The run time for
synchronization is derived by control parameter RuntimeYx
(x = 1, 2, or 3) multiplied by 1.25.
Synchronization by the controller is initiated:
after power up reset (initial start)
after 250 control steps as soon as control output is
below 5 %
if plant/system ON/OFF input is switched to OFF
out2
Y1/Y2/Y3
7 EN0B-0301GE51 R0104
R7426B,C TEMPERATURE CONTROLLER
Electric Heat Current Valve (pwm output)
The pulse-width modulated output is suitable for driving
electric heat current valves and is controlled from the heating
signal. The interval or total cycle time is set by the control
parameter RuntimeY3.
The diagram below shows as example, 60% Output Signal
with Motor RuntimeY3 set to 50 sec: YMode = 0; Y3Mode =
3.
on
off
30 50 70 80 100 sec
out1/out2
Y3
2-stage ON/OFF Sequence Control
The R7426B controllers convert the output signal into a twostage ON/OFF sequence output signal suitable for operating
relays. Two relays can be connected to provide sequence
control of e.g. two electric heater stages.
Parameter setting for Output Switching Position:
YMode = 0; YxMode (x = 2 or 3) = 1
on
off
Step2 on
Step1 on
30
25 65 70
100
Power
out2
out1
%
Y2/Y3
4-stage ON/OFF Electric Heating or Cooling
For YMode = 2, the output sequence of Y3/Y1 is controlled
from the heating signal and the output Y2 is controlled from
the cooling signal. For YMode = 3, the output sequence of
Y3/Y1 is controlled from the cooling signal and the output Y2
is controlled from the heating signal.
The output of Y2 is operated in accordance with Y2Mode.
Parameter setting: YMode = 2 or 3, Y1Mode and Y3Mode =
4
on
off
Step1 on
25
Step2 on
40 45
Step3 on
60 65
Step4 on
8580
Power
Y1 out2
Y1 out1
Y3 out2
Y3 out1
100 %20 Y3/Y1
6-stage ON/OFF Sequence Control Heating or
Cooling
The output sequence of Y3/Y2/Y1 is controlled from one
output signal, Main Temperature Control or Cascade Control.
Parameter setting: YMode = 1,
Y1Mode, Y2Mode, and Y3Mode = 4
Y1CTRF = 0 (cooling) or 1 (heating)
Step6 on
Step5 on
Step2 on
Step1 on
Power
3-stage Binary ON/OFF Sequence Control
The R7426B controllers convert the heating signal into a
three-stage binary ON/OFF sequence as shown in the
following diagram.
Parameter setting for Output Switching Position:
YMode = 0; Y3Mode = 2
off
on
Step1 on
25
Step2 on
Step3 on
75
70 100 %20 5045
Power
out2
out1
Y3
on
off
6 signal sequence of
Y3/Y2/Y1 out1/out2
15 100 %10
25 30
70 85
75
90
Y3/Y2/Y1
15-stage Binary ON/OFF Electric Heating and
Cooling
The output sequence of Y3/Y1 is controlled from the heating
signal. The output sequence of Y2 is controlled from the
cooling signal.
The output of Y2 is operated in accordance with Y2Mode.
Parameter setting: YMode=5
Step15 on
Step14 on
Step2 on
Step1 on
on
off
4.5 100 %
4 signal sequence of
Y3/Y1 out1/out2
11
6.5 Y3/Y1
13
95.5
89
91
Power
97.5
EN0B-0301GE51 R0104 8
R7426B,C TEMPERATURE CONTROLLER
Two-Position Damper Control
If the value of the control parameter YMode = 4, the damper
output signal Y1 operates as two-position control as follows:
If the controller mode OFF (Comfort- Standby- or Night-
mode), the output signal Y1 is set to 100%.
If the controller mode = OFF, the output signal Y1 is set to
0%.
The output sequence of Y2/Y3 operates as Temperature
Sequence Control with Heating and Cooling.
ON/OFF Output
The ON/OFF output is provided to switch fans, pumps, or
other MicroniK 200 controller without RTC.
If one of the following conditions occur the controller switches
the ON/OFF output from OFF to ON after a fixed 3-minute
time delay:
The controller mode OFF (Comfort, Standby, or Night
mode).
The night cycle program is active.
The optimum start program is active.
If one of the following conditions occur, the controller
switches the ON/OFF output from ON to OFF:
The controller mode = OFF.
The freeze protection input is active.
The following function will be active in flow water
temperature applications if the configuration parameter
Ctrltyp = Hi2:
The controller switches the ON/OFF output from ON to
OFF if the outside air temperature is above 8C and the
output signal Y1 = 0% for more than 5 minutes during
Comfort, Standby, or Night mode.
Analog Outputs on R7426C, only
Three output control signals are provided to control valve or
damper actuators or E/P transducers for pneumatic
actuators.
The full output range is 0...12 Vdc. The control range is
common to all outputs and is software-configurable using the
control parameter YRange to either 2...10 Vdc or 0...10 Vdc.
Each output can be selected for direct or reverse acting.
ADJUSTMENTS
Control Point / Setpoint Adjustment
(CPATYP)
The control or setpoint can be adjusted via the internal or an
external potentiometer connected to the CPA/SPA input. The
CPA/SPA type is selected using the control parameter
CPATYP (see page 2, Technical Data).
Calibration of Temperature Sensors
(T1CAL, T2CAL, and T3CAL)
In case of an offset as a result of long wiring lengths, the
temperature sensor inputs (T1, T2 and T3) can be adjusted
separately by the control parameters T1CAL, T2CAL, and
T3CAL.
WIRING
Wiring run
From controller to all
input and output
devices
Offset for temperature sensors due to wire resistance per
10 m distance from sensor to controller:
Type of wire
2
0.5mm
(AWG20)
1.0mm
(AWG17)
1.5mm
(AWG15)
(0.324F)
2
(0.162F)
2
(0.108F)
Type of
wires
local
standard
Temperature offset
Pt 1000 BALCO 500 NTC
0.18C
0.09C
0.06C
(0.54F)
0.15C
(0.27F)
(0.18F)
Length max.
1.0 mm
100 m 150 m
0.3C
0.1C
2
negligible
1.5 mm
2
9 EN0B-0301GE51 R0104
R7426B,C TEMPERATURE CONTROLLER
CONNECTIONS
200mV/%rh
24 V
R7426B
15
16
17
24V
18
19
2
20
e
p
o
24V
21
22
s
o
l
c
e
p
o
23
24
24V
s
o
l
c
25
26
e
p
o
24V
27
28
s
o
l
c
R7426C
*
i
e
r
S
r
P
o
f
Occupancy
T1
T2
T3
Freeze
prot.
f
a
r
t
e
I
n
l
a
u
B
l
e
n
a
e
c
s
X
W
r
h
CPA/SPA
T1
1
2
3
4
V
4
2
T
U
/
O
n
1
Y
1
U
T
/
O
e
2
T
O
U
/
n
2
Y
T
1
U
/
O
e
2
T
U
/
O
n
3
Y
1
T
O
U
/
e
T2
T3
5
6
7
8
9
10
11
12
B
13
A
14
= 0V
Occupancy
*
a
i
e
r
S
P
r
o
f
Freeze
prot.
I
n
l
e
n
a
T1
T2
T3
t
200mV/%rh
24 V
e
c
r
f
a
e
s
u
B
l
15
16
17
18
19
20
21
22
23
24
25
26
27
28
X
W
r
h
24V
V
4
2
V
0
.
.
1
.
/
2
0
24V
V
4
2
V
0
.
.
.
1
/
2
0
24V
V
4
2
V
0
.
.
.
1
/
2
0
24V
V
4
2
*
R7426B1014,C1012
On/Off Output
Y
1
2
Y
3
Y
R7426B2012,C2010
ON/OFF
24V
10
CPA/SPA
T1
T2
T3
B
A
9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
= 0V
W 303
Jumper1)State Description
W303
1)
Default jumper position = closed
2)
Cut (open) jumper W303 only if the T3 input is fed from
open
closed
2)
T3 supplied by this controller
T3 supplied from another controller
another controller (parallel connection, max. 6 devices).
This disconnects the T3 input from the internal power
supply.
Fig. 3. Connections and Jumper coding
CAUTION
Outputs are not isolated from power supply
Observe correct phasing with 24Vac power
supply
EN0B-0301GE51 R0104 10
MOUNTING AND DIMENSIONS
87 +
/-0.
2
R7426B,C TEMPERATURE CONTROLLER
All dimensions in mm.
121 +/- 0.3
= =
==
3.5
105
152
Honeywell
SEL
SET
198 +/-0.3
170 +/-0.3
= =
43
==
3.5
wall mounting
approx. 45 x 35
(cut-out for cables)
Fig. 4. Mounting and dimensions
(when mounting on DIN rail)
4.5
180 +/-0.2
front panel mounting
110 +/-0.3
130 +/-0.3
11 EN0B-0301GE51 R0104
R7426B,C TEMPERATURE CONTROLLER
HONEYWELL
Automation and Control Solutions
Honeywell GmbH
Böblinger Straße 17
D-71101 Schönaich
Phone: (49) 7031 63701
Fax: (49) 7031 637493
http://europe.hbc.honeywell.com
Subject to change without notice. Printed in Germany Manufacturing location certified to
EN0B-0301GE51 R0104
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