20
DESCRIPTION
Murelle Pro HE MkII
30
35
TEMPERATURE - PRESSURE
Max operating temperature [T max]
°C
85
Heating adjustment range
°C
20÷80
Domestic hot water adjustment range
°C
10÷60
Max operating pressure [PMS]
bar
2.5
kPa
250
Water content in boiler
l
4.75
Lower Heat Output (Hi)
G20 Hi.
9.45 kW/m
3
(15°C, 1013 mbar) - G31 Hi. 12.87 kW/kg (15°C, 1013 mbar)
5.6
Main water circuit
3
4
5
13
12
14
15
17
18
9
8
7
10
16
19
20
21
22
23
11
6
M
U
G
E
R
Sc
S
2
1
Fig. 10
KEY:
M System flow
R System return
U Domestic hot water outlet
E Domesti hot water inlet
S Safety valve outlet
G Gas supply
Sc Condensate outlet
1
Condensing heat exchanger
2
Combustion chamber
3
Fan
4
Thermal safety thermostat (TS)
5
Delivery sensor (SM)
6
Domestic hot water heat exchanger
7
Water pressure switch
8
Automatic bleed valve
9
Pump
10
System expansion vessel
11
Diverter valve
12
Automatic by-pass
13
Domestic hot water sensor (SS)
14
Gas valve
15
Domestic hot water flow meter
16
Domestic hot water filter
17
Boiler drain
18
System relief valve
19
Condensate siphon outlet
20
System flow cock
21
Gas cock
22
Domestic hot water inlet cock
23
System return cock
5.7
Sensors
The sensors installed have the following characteristics:
– Dual sensor (thermal safety/output) NTC R25°C; 10kΩ
– domestic hot water sensor NTC R25°C; 10kΩ
– external sensor NTC R25°C; 10kΩ
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
Murelle Pro HE MkII
30
35
Total capacity
l
9,0
Prefilling pressure
kPa
100
bar
1,0
Useful capacity
l
5,0
Maximum system content (*)
l
124
(*) Conditions of:
Average operating temperature 70°C (with high tempera-
ture system 80/60°C)
Start temperature at system filling 10°C.
