17
5.7
Sensors
The sensors installed have the following characteristics:
– Dual sensor (thermal safety/output) NTC R25°C; 10kΩ β25°-
85°C: 3435
– domestic hot water sensor NTC R25°C; 10kΩ β25°-85°C: 3435
– external sensor NTC R25°C; 10kΩ β25°-85°C: 3435
– Return probe NTC R25°C; 10kΩ β25°-85°C: 3435
– Evaporator probe NTC R25°C; 10kΩ β25°-85°C: 3435
Correspondence of Temperature Detected/Resistance
Examples of reading:
TR=75°C → R=1925Ω
TR=80°C → R=1669Ω.
TR
0°C 1°C 2°C 3°C 4°C 5°C 6°C 7°C 8°C 9°C
Resistance R (Ω)
0°C 27279
17959
12090
8313
5828
4161
3021
2229
1669
1266
973
26135
17245
11634
8016
5630
4026
2928
2164
1622
1232
25044
16563
11199
7731
5440
3897
2839
2101
1577
1199
24004
15912
10781
7458
5258
3773
2753
2040
1534
1168
23014
15289
10382
7196
5082
3653
2669
1982
1491
1137
22069
14694
9999
6944
4913
3538
2589
1925
1451
1108
21168
14126
9633
6702
4751
3426
2512
1870
1411
1079
20309
13582
9281
6470
4595
3319
2437
1817
1373
1051
19489
13062
8945
6247
4444
3216
2365
1766
1336
1024
18706
12565
8622
6033
4300
3116
2296
1717
1300
998
10°C
20°C
30°C
40°C
50°C
60°C
70°C
80°C
90°C
100°C
5.8
Expansion vessel
The expansion vessel installed on the boilers has the following
characteristics:
Description
U/M
UNIQA.REVOLU-
TION
Total capacity
l
8,0
Prefilling pressure
kPa
100
bar
1,0
Useful capacity
l
4,0
Maximum system content (*)
l
109
(*) Conditions of:
Average maximum temperature of the system 85°C
Start temperature at system filling 10°C.
m
CAUTION
– For systems with water content exceeding the max-
imum system content (as indicated in the table) an
additional expansion vessel must be prearranged.
– The difference in height between the relief valve
and the highest point of the system cannot exceed
6 metres. If the difference is greater than 6 metres,
increase the prefilling pressure of the expansion
vessel and the system when cold by 0.1 bar for each
meter increase.
5.9
Circulation pump
The flow-head performance curve available for the heating sys-
tem is shown in the graph below.
RESIDUAL HEAD (mbar)
0
0
800 1000 1200 1400
1600
600
400
200
100
200
300
400
500
25
FLOW (l/h)
Fig. 12
5.10 Heat recovery system
Certain conditions must apply for the heat recovery system to
work. The system return temperature must be below the value
set under
(PAR 46)
. The combustion air temperature must be
between the value set under
(PAR 06)
and
(PAR 07)
. Once all of
these conditions have been met, the
>
symbol shows or flashes
on the display. If the
>
symbol is on the screen, the heat recov-
ery system is in operation; if the symbol is flashing, the boiler is
calculating the time required to start up correctly.
