2.7
GAS SYSTEM CONNECTION
- The unit should be supplied with gas having the characteristics and the pressure shown on Table II.
- The gas pressure is measured at the initial pressure outlet with the burner on (see Fig. 1) and art. 2.9.1.
- The equipment is tested and preset in order to work with the gas indicated on the external adhestive plate.
*N.B. Should the supply pressure vary more than +10% of the nominal pressure, it is advisable to install a pressure
regulator ahead of the unit to guarantee the nominal pressure.
- Gas supply connection should be performed by means of metal piping of an appropriate cross section and an approved
shutoff cock should be fitted at source.
- After connecting to the gas system, check for any leaks in the connecting points with special instruments or with soapy
water.
2.8
DISCHARGE OF EXHAUST FLUE PRODUCTS
The units should be installed in premises suitable for the discharge of flue products, which must occur in compliance with
the installation instructions. Our equipment (see Tables 1.1.S, 1.1.B for technical data) is classified as:
2.8.1
GAS UNITS TYPE A
They are not suitable to be connected to a flue discharge control.
The gas unit should be positioned beneath a draft hood with its system complying with the Regulations. (This unit needs at
least 2cu.m/hr • kW T.C. (Thermal Capacity).
Check kitchen ventilation: it should by complying with the Regulations in force.
2.9
HOW TO ACHIEVE THE NOMINAL THERMAL CAPACITY
Check whether the unit is fitted for the gas type, pressure and category corresponding with the main gas supply.
Indication shown on packing and/or the label of the unit.
If the unit is fitted for another gas type or pressure, you need to first effect a change over to the other gas type.
See Table II art. 2.6. for the nozzle, the idle screw (bypass), the primary air regulation, (X mm), the pilot nozzle and the 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= G20 - 20mbar
3+= G30 29mbar and/or G31 - 37mbar coupled gas and pressure. In our sector, we almost always have to deal with G31 -
37mbar!
Table II shows the types of gas and pressure for all burners and respective nozzles, the X mm distance for the adjustment of
primary air , the idle screw (bypass), the pilot nozzle, the maximum and minimum pressure at nozzle, the maximum and
minimum thermal capacity, and the gas consumption in l/hr (15°C) or in g/hr in the case of L.P.G.
Attention: If the incoming gas' "dynamic" pressure to the unit is lower than the minimum pressure on Table II, connection is
prohibited; furthermore, the fitter should notify the gas Company that the supply pressure is too low.
N.B. Should the pressure vary more to than +10% of the nominal pressure, e.g. for G20 > 22mbar, it is advisable to mount a
pressure regulator ahead of the unit in order to guarantee the nominal pressure.
Should the supply pressure exceed the maximum pressure on Table II, e.g. for G20 > 25mbar, notify the gas Company.
Make sure the inlet and nozzle pressures agrees with the values shown on Table II.
2.9.1
INCOMING PRESSURE CHECK (PE) FIG. 1
Pressure is measured with a manometer 0÷80mbar (precision at least 0.1mbar).
The pressure socket Fig. 1 is located on the G 1/2" gas ramp behind the panel; undo the screw (A) of the pressure socket (B),
attach the silicone rubber to the manometer, ignite the burner and take the incoming "dynamic" pressure.
Fasten the screw (A) back with a gas washer (C), check gas sealing with soapy water.
2.9.2
NOZZLE PRESSURE CHECK (PI)
The pressure (F) socket is located above the nozzle holder.
The silicone rubber is prepared for high temperatures and should be protected with tin foil to avoid its burning.
2.9.3
LIQUID GAS OPERATION CONTROL
Check whether the fitted nozzles comply with the indications on Table II.
Check whether the incoming pressure complies with the indications on Table II.
Make sure that the L.P.G. gas system has two pressure regulators of suitable capacity and that the evaporation capacity is
sufficient.
See also the publication "Installation Regulations and Characteristics of L.P.G. Systems".
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GB