Vector TCI-W Manual page 10

PI control sequence
Parameter Description
Offset for heating PI sequence
1L 09
1L 10 Offset for cooling PI sequence
P-band heating
1L 11
1L 12 P-band cooling
Integral gain heating (0.1 steps)
1L 13
low= slow reaction, high= fast reaction
1L 14 Integral gain cooling(0.1 steps)
Measuring interval integral (seconds)
1L 15
low= fast reaction, high value= slow reaction
Proportional control(P-band)

The proportional control function calculates the output based on the difference between setpoint and measured value.
The proportional band (P-band) defines the difference between setpoint and measured value which will result in a 100%
output. For example, with a heating or reverse 0-10v control sequence, and a 2.0°C (4.0°F) P-band value, at 10v the
controller will be 2.0°C (4.0°F) below setpoint. This is the working range of the proportional control sequence.
Setting the proportional band to 0 disables proportional control.
Integral and Differential control

Proportional control is in most cases a very stable control mode. The flaw of proportional control alone, however, is
that the setpoint is normally not reached. As the measured value gets closer to the setpoint, the output reduces until
it reaches a point, a fraction above or below the setpoint, where the output equals the load. To reach the setpoint and
achieve a higher level in comfort the Integral/Differential function should be activated.
Integral Gain (KI)dynamically increases the output by the selected KI value every Measuring Interval TI until the
setpoint is reached. The challenge is to prevent hunting, where the output increases too fast, the temperature
overshoots the setpoint, the output goes to 0, the temperature undershoots the setpoint, and the cycle repeats itself.
Hunting may result if the integral gainis too high or measuring interval too short. Each system is different. To prevent
instability the P-band should be extended when integral gain is active (L14 or L15 set above 0).
Setting the integral gain to 0 disables integral and differential control.
P-band
Measuring interval (TI)
Integral gain (KI)
Heating/Reverse
Y , Y
H1
100
0
Doc: 70-00-0158, V1.1, Date: 20160621
Subject to alteration
Recommended Values
heating (air) heating (radiant)
2–3°C(4–6°F)
2
0.2 0.1
R1
W
W
C
H
X X
PH DZ
X
SBY
humidifying
5 15
0.1
Cooling/Direct
Y Y
C1, D1
T [°C, F]
X
PC
U [V, mA]
X
SBY
© Vector Controls GmbH, Switzerland
TCI-W Universal Controller
C C
ONTROL LOOP ONFIGURATION
Range
per input
per input
per input
per input
0–25.5
0–25.5
0–255
cooling dehumidifying
1–1.5°C(2–3°F)
1 70
0.2 0.3
Legend
T, U Input signal temp/universal
X
P-band heating/direct
PH
X
P-band cooling/reverse
PC
X
Dead zone h/c set points
DZ
X
Economy mode set point shift
SBY
W
Set point heating/reverse
H
W
Set point cooling/direct
C
Y Y
PI sequence heating/reverse
H1, R1
Y Y
PI sequence cooling/direct
C1, D1
Default
0
0
2.0°C(4.0°F)
2.0°(4.0°F)
0.0
0.0
1 sec.
pressure
1
0.8
Page 10