- 23 -
GB
- The unit needs to be supplied with gas with the characteristics and pressure shown in Table II.
- The gas pressure is measured at the initial pressure test point with the burners on (see Fig. 1 and art. 3.6.1).
- The oven is tested and fitted for operating with natural gas H G20 - 20 mbar.
* N.B. Should the supply pressure vary more than +10% of the nominal pressure, it is advisable to install a pressure
regulator upstream from the unit to guarantee the nominal pressure.
- Hooking up to the gas mains must be done with a metal pipe of suitable cross-section and a shut-off valve must be installed
upstream to standards.
- After hooking up to the gas mains, check there is no leakage at the fitting points with the soap solution method.
3.1
DISCHARGING THE PRODUCTS OF COMBUSTION UNDER A SUCTION HOOD
UNIT TYPE: A
The gas oven should be positioned under a suction hood whose system must have specifications in conformity with the
standards. This unit needs at least 2 m
3
/h • kW T.C. (T.C. = Thermal Capacity).
Check the ventilation in the kitchen. It must be in accordance with current standards.
3.2
HOW TO OBTAIN THE NOMINAL THERMAL CAPACITY
Check whether the unit is fitted for the gas type, pressure and category corresponding to the main gas supply.
Information shown on the packing and/or unit label. If the unit is fitted for another type of gas or pressure, you first need to
transform it for working with the other kind of gas.
See Table II for the nozzle, idle screw (by-pass), primary air regulation, (X mm), pilot nozzle and nozzle pressure for the main
burner.
N.B.:
The names of nozzles ”2H” and ”3+” are shown on the left side of Table II.
2H = G 20 - 20 mbar
3 + = G 30 - 29 mbar and/or G 31 - 37 mbar coupled gas and pressure.
In our sector we nearly always have to deal with G 31 - 37 mbar!
Table II shows the types of gas and pressure for all burners and their nozzles, the distance X mm of the primary air adjustment
(see Fig. 4), the idle screw (by-pass), the pilot nozzle, the maximum and minimum nozzle pressure, the maximum and
minimum thermal capacity and the gas consumption in l/h (15°C) or in g/h in the case of L.P.G.
Caution:
If the ”dinamic” pressure of the gas upstream from the device is lower than the minimum pressure of Table II
connection is prohibited; furthermore, the fitter must notify the gas company that the supply pressure is too low.
N.B.:
If the pressure varies by more than +10% of the nominal pressure, e.g. for G 20 • 22 mbar, it is advisable to mount a
pressure regulator upstream of the unit to guarantee the nominal pressure.
Should the supply pressure exceed the maximum pressure of Table II, e.g. for G 20 • 25 mbar, notify the gas company.
Check whether the incoming and nozzle pressures correspond to the values given in Table II.
3.3
PRESSURE CHECK
INCOMING PRESSURE CHECK (Pe) Fig. 4
The pressure is measured with a pressure gauge 0 ÷ 80 mbars (precision at least 0.1 mbars).
The pressure test point Fig. 4 is on the G 3/4 gas ramp behind the instrument panel; undo the screw of the pressure test point
(A), attach the silicone rubber hose to the pressure gauge, ignite the burner and note the incoming ”dynamic” pressure.
Fasten the screw back on with a gas washer, check there is no leakage with the soap solution method.
NOZZLE PRESSURE CHECK (Pi) Fig. 1
The pressure test point is over the nozzle holder (Fig. 1); undo the screw of the pressure test point (A), attach the silicone
rubber hose to the pressure gauge, ignite the burner and note the incoming nozzle pressure.
Fasten the screw back on with a gas washer, check there is no leakage with the soap solution method.
The silicone rubber is suitable for high temperatures, but it should be protected with tin foil.
3.4
CHECKING THE GENERAL THERMAL CAPACITY
Any transformation for another type of gas (see Sect. 4) must be performed by an authorized fitter or assistant.
The thermal capacity to check may be:
- the nominal thermal capacity given on the data plate
- the maximum thermal capacity in the maximum position
3.
HOOK-UP WITH THE GAS SYSTEM
Содержание G4SF9
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