CONDEXA PRO
53
Safety functions on the Slave boards
When the Outlet Temperature > 90°C for 5s, the Slave board shuts down (no. 46).
When the Return Temperature > 80°C for 5s, the Slave board shuts down (no. 47).
When the Flue Gas Temperature > 80°C for 5s, the Slave board shuts down (no. 48) and the fan operates for 10 minu-
tes at maximum speed.
The Slave board can protect the main exchanger against the dangers of low water circulation, in three ways:
1 = by flow switch (water differential pressure switch)
2 = by controlling the difference between the outlet and return temperature DT
3 = by flow switch and DT
The control on the DT uses a parameter, DT_max (pre-set to 35°C) and limits the output of the burner as follows:
if DT_max -5°C > DT > DT max – 10°C
burner modulation
if DT_max > DT > DT_max –5°C
burner at minimum
if D_T > D_T_max
burner off.
MANAGEMENT OF THE MIXING VALVE
The mixing valve is controlled by the following parameters:
Mix_valve_step_open_time: Par.28 pre-set to 5s
Mix_valve_step_close_time: Par.29 pre-set to 7s
Mix_valve_interval_time: Par.30 pre-set to 5s
Mix_valve_p_hyst: Par.31 pre-set to 2°C
Mix_valve_still_hyst: Par.32 pre-set to 2°C
Before opening or closing, the valve waits the time set for
Par.30.
It opens if:
T_low inlet temperature < Setpoint_low – Par32
It closes if:
T_ low inlet temperature > Setpoi Par32
Within the interval, the valve remains in the current posi-
tion.
If:
T_ low inlet temperature < Setpoint_low – Par31 it opens
for a time equal to half of the value set for Par. 28
If:
T_ low inlet temperature > Setpoi Par31 it closes
for a time equal to half of the value set for Par. 29.
Time (s)
0
5
10
15
20
Manifold T
emperature
-5
5
15
25
35
45
55
Mixer Outlet Temperature (
°
C)
20
30
40
50
60
V
alve Closing-Opening (s)
-4
-3
-2
-1
0
1
3
25
35
45
55
2
Open
Close
default
Par. 31 = 10
Summary of Contents for CONDEXA PRO 100 S
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