Main Features - Sit 820 NOVA Instructions D'utilisation Et D'installation

9956820-02_MI_820 NOVA_A4
USE AND INSTALLATION
INSTRUCTIONS
Multi-functional gas valve with On-Off gas flow control suitable for use with boilers, catering equipment, furnaces,
radiant tubes and space heaters. SIT 820 NOVA is available in AC-powered versions (220/240V or 24V) or versions
powered by a millivolt generator which permits complete control of the appliance without requiring main supply
voltage. All versions are available, on request, with manual adjustment of the gas flow.

MAIN FEATURES

Three position control knob: Off, Pilot and On (MS)
Thermoelectric flame failure device with re-start interlock (GM)
Silent-operation automatic shut-off valve (EV)
Servo-controlled pressure regulator (PR)
Step opening ignition device (optional) (SO)
Manual gas flow adjustment (optional) (MA)
Pilot outlet with flow restrictor (RQ)
Inlet and pilot filters (FL)
Inlet and outlet pressure test points
Threaded 1/2 gas inlet and outlet with provision for flange connection
Connection for combustion chamber pressure compensation (optional).
WORKING DIAGRAM
Versions with On-Off gas flow control
FL
GAS
INLET
SIT 820 NOVA mV
Automatic shut-off valve
powered by millivolt generator
MANUAL GAS FLOW ADJUSTMENT
SIT 820 NOVA mV is also available with manual gas flow adjustment. By turning the adjustment knob from the HI to LO
position, gas flow reduction is obtained depending on application conditions.
Flow reduction [%]
50
40
30
20
10
0
6
4
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EV
GM
MS
PR SO
FL RQ
Gas flow reduction passing
from the HI position
to the LO position
as a function of the outlet
8 10 12 14
Pu [mbar]
Versions with manual gas flow adjustment
GM
FL MS
GAS
MAIN
INLET
BURNER
PILOT
BURNER
SIT 820 NOVA
AC-powered automatic
shut-off valve
pressure Pu.
GB
EV
PR MA SO
MAIN
BURNER
PILOT
BURNER
FL RQ