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TH-3xxSx1
• COOLING/COOLING mode (
M01
=11)
The “
COOL
” icon is on to indicate that cooling mode is active.
The regulation logic is as follows:
100
0
Temp.
PBC
(
I23
)
BCS
(
I08
)
DIFF
(
I20
)
PBC
(
I23
)
AO2
AO1
Outputs
valves
speed 1
Fan
speed 3
speed 2
(
I25
)
0%
100%
(
I26
)
(
I27
)
% opening
valve
DO1
DO2
DO3
If the operating temperature rises above
I08
the first valve V1 starts opening (output
AO1
). Icon turns on.
The valve can be regulated with PI action if the integral time
I24
is non-zero or with only proportional action if
I24
=0.
The fan starts when the valve reaches the aperture defined in
I25
and after startup delay
I36
.
If the temperature continues rising, the speed switches from speed 1 to speed 2 when valve V1 reaches the aperture
given in
I26
. The speed switches from speed 2 to speed 3 when valve V1 reaches the aperture given in
I27
.
Each speed is subject to a hysteresis of 20% of its activation point.
For example, for speed 3:
if
I27
=100%, speed 3 is activated when the valve reaches fully open and is deactivated when the valve closes by 20%
of
I27
, which is 80% of fully open in this case.
If the temperature drops below
I08
+
I20
, the second valve V2 opens (output
AO2
). This is regulated with proportional
action.
If the temperature rises above
I08
+
I20
+
I23
, valve V2 is fully open.
Icon
turns off when valve V1 closes again, in which case the fan stops if
I28
=0 or 3. The fan maintains speed 1 if
I28
=1 or 2. The fan maintains speed selected manually if
I28
=4 or 5.
Wiring diagram
N L
DI
1
GN
D
DI
2
AI1 GN
D
AI2
DO
1
DO
2
GN
D
T1
T2
S1
S2
M1
I
II
III
DO
3
CO
M
N
L
230V
ac
V1
AO1 GN
D
G
G0
24V
ac
Y G0
AO2 GN
D
V2
Y G0
G
G0
24V
ac
A +
B
-
MODBUS RTU
(TH-xMxxx)
