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TH-3xxSx1
• HEATING/HEATING mode (
M01
=1)
The “
HEAT
” icon is on to indicate that heating mode is active.
The regulation logic is as follows:
100
0
Temp.
PBH
(
I22
)
Outputs
valves
BHS
(
I07
)
DIFF
(
I20
)
PBH
(
I22
)
AO1
AO2
speed 1
% opening
valve
Fan
speed 3
(
I25
)
0%
100%
speed 2
(
I26
)
(
I27
)
DO1
DO2
DO3
If the operating temperature drops below
I07,
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 de-
fined in
I25
and after startup delay
I36
.
If the temperature continues falling, 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 acti-
vation point.
For example, for speed 3:
if
I27
=100%, speed 3 is activated when the valve reach-
es 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
I07
-
I20
, the second
valve V2 opens (output
AO2
). This is regulated with pro-
portional action.
If the temperature drops below
I07
-
I20
-
I22
, valve V2
is fully open.
Icon turns off when valve V1 closes again, in which case the fan stops if
I28
=0 or 2. The fan maintains speed 1 if
I28
=1 or 3.
The fan maintains speed selected manually if
I28
=4 or 6.
N.B.: if the minimum thermostat function is active, the thermostat itself must be closed when the valve is in regulation,
otherwise the fan will not start.
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
A +
B
-
V2
Y G0
G
G0
24V
ac
MODBUS RTU
(TH-xMxxx)
