84
13 TEMPERATURE PROTECTION
The difference between Flow temperature and Return Temperature is continuously monitored. A too big difference
can indicate a defective pump or a clogged heat exchanger. To protect the boiler, the burner controller reduces the
input when the temperature difference ΔT becomes too high:
At maximum boiler input ΔT
is limited to 35°C (63 °F) - (
Hx_Diff_DeltaT_Min )
In between 35°C (63 °F) and 43 °C (77 °F) boiler input modulates between minimum and maximum.
At min. boiler input ΔT
above 43 °C (77 °F) is allowed ((
Hx_Diff_DeltaT_Min )+8 °C (+14.4 °F)
Above ΔT = 48 °C (86 °F), the boiler is switched OFF during
HX
_
Diff_Max_Wait_Time
.
Relevant factory set variables
Parameter
Level
Factory Setting.
Range
HX Diff DeltaT Min
3: Factory
35 ºC (63 ºF)
10 ….80 ºC (18….144 ºF)
HX Diff Max Wait Time
Wait time after upper limit primary heat exchanger
differential has been exceeded.
3: Factory
180 Sec.
1….255 Sec.
43
48
0
20
40
60
80
100
120
20
25
30
35
40
45
50
55
b
o
il
er
in
p
u
t [%
]
delta T [°C]
boiler input control
high power
low power
off
Summary of Contents for S-CBX 105
Page 2: ......
Page 40: ...40 9 10 Flue Terminal Positioning ...
Page 42: ...42 9 11 1 FIGURE 12 LINE G ...
Page 55: ...55 11 5 Ladder Logic Diagram ...
Page 56: ...56 11 6 Electrical schematics ...
Page 57: ...57 ...
Page 137: ......