96
4.1
GAS VALVE
The boiler, is equipped standard with the
HONEYWELL VK 8115M gas valve (fig. 23).
4.2
ADJUSTMENT
OF HEAT OUTPUT
FOR HEATING
To adjust boiler heat output for heating pur-
poses, i.e., modifying the setting made at the
factory which is approximately 17 kW, use a
screwdriver to adjust the heating heat out-
put trimmer (10 fig. 20).
To increase working pressure, turn the trim-
mer clockwise; to reduce pressure, turn the
trimmer counterclockwise.
To determine boiler heat output setting,
check energy consumption by observing the
meter and then compare with the values
shown in
Tables 4 - 4/a - 4/b
; or measure
“air
∆
p” with a digital pressure gauge con-
nected up as shown in fig. 24.
Compare values with those shown in
Tables
4 - 4/a - 4/b
.
4
USE AND MAINTENANCE
1
2
3
4
5
Fig. 23
KEY
1
Regulation intake
2
EV1-EV2 coils
3
Pressure inlet upstream
4
Pressure inlet downstream
5
OFF-SET
KEY
1
Gas pressure intake
2
Gas valve
3
Mixer intake (–)
4
Ventilator intake (+)
5
Nozzle
6
Fan
7
Air/gas mixer
8
Air pressure switch
9
Digital pressure gauge
Fig. 24
0
30
20
10
∆
p aria mm H
2
O
P
o
tenza t
er
mica kW
25
20
10
15
50
40
60
5
30
50-30
°
C
35
70
80-60
°
C
0
30
20
10
∆
p aria mm H
2
O
P
o
tenza t
er
mica kW
25
20
10
15
50
40
60
5
30
50-30
°
C
35
70
80-60
°
C
G20
G31
4.2.1
Diagram illustrating heat output in relation to “air
∆
p”
Fig. 25/a
TABLE 4/a - G20
*
Air
∆
p is measured during boiler operation using a differential pressure gauge connected to the ventilator intake.
** The gas consumptions refer to the calorific value at standard conditions at 15°C - 1013 mbar.
Variable heat output
Air
∆
p*
Gas consumption**
(80-60°C) (50-30°C)
(80-60°C) (50-30°C)
G20
kW
kW
mm H
2
O
mm H
2
O
m
3
/h st
28,3
31,0
63,8
66,4
3,06
22,9
25,0
45,0
45,0
2,48
16,1
17,6
25,0
25,0
1,75
10,4
11,4
8,4
9,2
1,14
TABLE 4/b - G31
Variable heat output
Air
∆
p*
Gas consumption**
(80-60°C) (50-30°C)
(80-60°C) (50-30°C)
G31
kW
kW
mm H
2
O
mm H
2
O
m
3
/h st
28,3
31,0
68,4
70,4
1,52
21,8
23,4
45,0
45,0
1,19
15,4
16,6
25,0
25,0
0,84
10,4
11,4
9,2
9,5
0,55
Heat
out
out
(kW)
Air
∆
p mm H
2
O
Heat
out
out
(kW)
Air
∆
p mm H
2
O
