Biasi GARDA HE M96.24SM/B2, Руководство по обслуживанию

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23
11
Modulating gas valve
11.1
Function
The Modulating gas valve A in Fig. 46 controls the gas
inflow to the boiler burner.
A
Fig. 46
By means of an electric command given to the on---off
operators the passage of the gas through the Modula-
ting gas valve can be opened or closed.
By means of an electric command given to the modula-
tion operator the pressure can be varied and therefore
the gas flow rate to the burner (modulation). The mo-
dulation operator has mechanical components which
allow the adjustment of the minimum and maximum
pressure exiting the valve.
11.2 Nomenclature of the parts (Fig. 47)
1 Minimum gas pressure adjustment
2 Maximum gas pressure adjustment
3 Modulation operator’s electric connectors
4 On---off operators electric connector
5 On---off operators
6 Gas valve inlet pressure test point
7 Gas valve outlet pressure test point
8 Modulation operator
5
8
3
7
4
1
2
6
Fig. 47
11.3 Adjustment
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove the front panel of the case.
2 Open the gas valve inlet pressure test point (6 in
Fig. 47) at the valve input, connect a suitable
pressure gauge and check the gas pressure of
the supply network.
3 Remove the gauge and close the pressure test
point 6.
4 Open the gas valve outlet pressure test point (7
in Fig. 47) and connect the gauge;
5 Remove the protection cap
B
(Fig. 48) from the
mechanical pressure adjustment components
levering with a flat screwdriver in the slots
C
.