TCY-T0121 Intelligent Compact Controller
Version: 2004-07
Page 2/12
Control Functions
The compact controller TCY operates with four different control modules. These modules can be activated and
parameterized according to the application to be controlled. The main modules are: Temperature PI, Temperature
On/Off, Universal PI and Universal On/Off. All modules operate simultaneously. In order to use the controller, at
least one control module must be enabled. The outputs that respond to each control loop need to be assigned in the
output section.
Temperature Control Module
HC -00: 2-pipe or 4-pipe system. Select 2-pipe system if the system has only a single coil that operates as heater in
winter and cooling device in summer. Select 4-pipe system, if specific heating and cooling coils are available.
HC -01: Dead Zone Span. The cooling setpoint W
C
consists of the heating setpoint and the dead zone span. Changing
the cooling setpoint in 2-pipe mode therefore changes as well the heating setpoint. The factory setting for the dead
zone span is 1K.
Modulating PI-Control
The temperature PI control mode is enabled with parameter HC -02. The controller maintains the temperature set
point by calculating the output position based on proven PI control algorithms.
Control parameters:
HC -03, HC -04: P-bands for heating and cooling are programmable. The factory setting is 2 K. The p-bands are
disabled if 0 is selected.
HC -05: A large I part increases the swinging tendency of the control loop. Limiting the integral part may reduce this
tendency. The I-part is disabled if 0 is selected.
HC -06: Tn, Reset time of Analog loop integral. Tn is the time needed for the integral to run from 0 to 100%. The
range is 0.5 – 30 min. The setting depends on the control application. For temperature control of a medium sized
room, a setting of 5-10 minutes is appropriate. For pressure control on a VAV box a value of 3 minutes is
recommended, depending on the speed of the actuator.
T
Room Temperature
W
H
Setpoint Heating
X
PH
Proportional Band Heating
W
C
Setpoint Cooling = W
H
+ X
DZ
X
PC
Proportional Band Cooling
Y
H
Output signal Heating
X
DZ
Dead zone
Y
C
Output signal Cooling
Tn
Reset time of Integral
Y
I
Integral part of output signal
Temperature On/Off control
The control mode is enabled with parameter HC -07. On/Off control is suitable to operate fan coil valves and reheat
or cooling compressor stages. By providing the dry Normally Open contact, any voltage from 10…250V for actuators
and switching stages may be used. Switching power is limited to 0.5A per stage.
Control parameters:
HC -08: Enables a second stage for reheat. HC -09: Enables a second compressor stage for cooling.
HC -10, HC -11: The switching span determines the temperature difference required for the next heating stage to be
activated.
HC -12: The hysteresis defines when a heating stage is switched off. The aim is to avoid unnecessary switching of
heating stages thus increasing the life span of involved equipment as well as saving energy.
Delayed switching. The upper heating/ cooling stages will not switch on at the same time. The higher stage will not
start earlier than 5 seconds after the lower stage has been initiated.
H
RC
Hysteresis Heating/Cooling
X
RC
Switching Span Heating/Cooling
Y
H
[%]
100
0
X
PH
W
H
X
PC
X
DZ
Heating Mode
Cooling Mode
T [K]
Y
C
[%]
W
C
Y
I
[%]
100
0
T n
W
X
I Control Part
t [min]
Stage 2
Heating
Stage 1
0
X
RC
W
H
On/off Control
T [K]
H
RC
W
C
Cooling
X
DZ
