Unigas G258A Operating manual

M039513CA 0.0 11/2021
BURNERS - BRUCIATORI - BRULERS - BRENNER - QUEMADORES - ГОРЕЛКИ
Microprocessor controlled
MANUAL OF INSTALLATION - USE - MAINTENANCE
LMV 2x/3x
Gas burners
G258A
G335A
G380A
G400A

2
DANGERS, WARNINGS AND NOTES OF CAUTION
THIS MANUAL IS SUPPLIED AS AN INTEGRAL AND ESSENTIAL PART OF THE PRODUCT AND MUST BE DELIVERED TO THE
USER.
INFORMATION INCLUDED IN THIS SECTION ARE DEDICATED BOTH TO THE USER AND TO PERSONNEL FOLLOWING
PRODUCT INSTALLATION AND MAINTENANCE.
THE USER WILL FIND FURTHER INFORMATION ABOUT OPERATING AND USE RESTRICTIONS, IN THE SECOND SECTION
OF THIS MANUAL. WE HIGHLY RECOMMEND TO READ IT.
CAREFULLY KEEP THIS MANUAL FOR FUTURE REFERENCE.
1) GENERAL INTRODUCTION
The equipment must be installed in compliance with the regulations in
force, following the manufacturer’s instructions, by qualified personnel.
Qualified personnel means those having technical knowledge in the
field of components for civil or industrial heating systems, sanitary hot
water generation and particularly service centres authorised by the
manufacturer.
Improper installation may cause injury to people and animals, or
damage to property, for which the manufacturer cannot be held liable.
Remove all packaging material and inspect the equipment for integrity.
In case of any doubt, do not use the unit - contact the supplier.
The packaging materials (wooden crate, nails, fastening devices, plastic
bags, foamed polystyrene, etc), should not be left within the reach of chil-
dren, as they may prove harmful.
Before any cleaning or servicing operation, disconnect the unit from
the mains by turning the master switch OFF, and/or through the cut-
out devices that are provided.
Make sure that inlet or exhaust grilles are unobstructed.
In case of breakdown and/or defective unit operation, disconnect the
unit. Make no attempt to repair the unit or take any direct action.
Contact qualified personnel only.
Units shall be repaired exclusively by a servicing centre, duly authorised
by the manufacturer, with original spare parts and accessories.
Failure to comply with the above instructions is likely to impair the unit’s
safety.
To ensure equipment efficiency and proper operation, it is essential that
maintenance operations are performed by qualified personnel at regular
intervals, following the manufacturer’s instructions.
When a decision is made to discontinue the use of the equipment,
those parts likely to constitute sources of danger shall be made harm-
less.
In case the equipment is to be sold or transferred to another user, or in
case the original user should move and leave the unit behind, make
sure that these instructions accompany the equipment at all times so
that they can be consulted by the new owner and/or the installer.
This unit shall be employed exclusively for the use for which it is
meant. Any other use shall be considered as improper and, therefore,
dangerous.
The manufacturer shall not be held liable, by agreement or otherwise, for
damages resulting from improper installation, use and failure to comply
with the instructions supplied by the manufacturer.The occurrence of any
of the following circustances may cause explosions, polluting unburnt
gases (example: carbon monoxide CO), burns, serious harm to people,
animals and things:
- Failure to comply with one of the WARNINGS in this chapter
- Incorrect handling, installation, adjustment or maintenance of the burner
- Incorrect use of the burner or incorrect use of its parts or optional supply
2) SPECIAL INSTRUCTIONS FOR BURNERS
The burner should be installed in a suitable room, with ventilation ope-
nings complying with the requirements of the regulations in force, and
sufficient for good combustion.
Only burners designed according to the regulations in force should be
used.
This burner should be employed exclusively for the use for which it
was designed.
Before connecting the burner, make sure that the unit rating is the
same as delivery mains (electricity, gas oil, or other fuel).
Observe caution with hot burner components. These are, usually, near
to the flame and the fuel pre-heating system, they become hot during
the unit operation and will remain hot for some time after the burner
has stopped.
When the decision is made to discontinue the use of the burner, the user
shall have qualified personnel carry out the following operations:
a Remove the power supply by disconnecting the power cord from the
mains.
b Disconnect the fuel supply by means of the hand-operated shut-off
valve and remove the control handwheels from their spindles.
Special warnings
Make sure that the burner has, on installation, been firmly secured to
the appliance, so that the flame is generated inside the appliance fire-
box.
Before the burner is started and, thereafter, at least once a year, have
qualified personnel perform the following operations:
a set the burner fuel flow rate depending on the heat input of the
appliance;
b set the flow rate of the combustion-supporting air to obtain a combu-
stion efficiency level at least equal to the lower level required by the
regulations in force;
c check the unit operation for proper combustion, to avoid any harmful or
polluting unburnt gases in excess of the limits permitted by the regula-
tions in force;
d make sure that control and safety devices are operating properly;
e make sure that exhaust ducts intended to discharge the products of
combustion are operating properly;
f on completion of setting and adjustment operations, make sure that all
mechanical locking devices of controls have been duly tightened;
g make sure that a copy of the burner use and maintenance instructions
is available in the boiler room.
In case of a burner shut-down, reser the control box by means of the
RESET pushbutton. If a second shut-down takes place, call the Tech-
nical Service, without trying to RESET further.
The unit shall be operated and serviced by qualified personnel only, in
compliance with the regulations in force.
3) GENERAL INSTRUCTIONS DEPENDING ON FUEL USED
3a) ELECTRICAL CONNECTION
For safety reasons the unit must be efficiently earthed and installed as
required by current safety regulations.
It is vital that all saftey requirements are met. In case of any doubt, ask
for an accurate inspection of electrics by qualified personnel, since the
manufacturer cannot be held liable for damages that may be caused
by failure to correctly earth the equipment.
Qualified personnel must inspect the system to make sure that it is
adequate to take the maximum power used by the equipment shown
on the equipment rating plate. In particular, make sure that the system
cable cross section is adequate for the power absorbed by the unit.
No adaptors, multiple outlet sockets and/or extension cables are per-
mitted to connect the unit to the electric mains.
An omnipolar switch shall be provided for connection to mains, as
required by the current safety regulations.
The use of any power-operated component implies observance of a
few basic rules, for example:
-do not touch the unit with wet or damp parts of the body and/or with
bare feet;
-do not pull electric cables;
-do not leave the equipment exposed to weather (rain, sun, etc.)
unless expressly required to do so;
-do not allow children or inexperienced persons to use equipment;
The unit input cable shall not be replaced by the user.
In case of damage to the cable, switch off the unit and contact quali-
fied personnel to replace.
When the unit is out of use for some time the electric switch supplying
all the power-driven components in the system (i.e. pumps, burner,
etc.) should be switched off.

3
3b) FIRING WITH GAS, LIGHT OIL OR OTHER FUELS
GENERAL
The burner shall be installed by qualified personnel and in compliance
with regulations and provisions in force; wrong installation can cause
injuries to people and animals, or damage to property, for which the
manufacturer cannot be held liable.
Before installation, it is recommended that all the fuel supply system
pipes be carefully cleaned inside, to remove foreign matter that might
impair the burner operation.
Before the burner is commissioned, qualified personnel should inspect
the following:
a the fuel supply system, for proper sealing;
b the fuel flow rate, to make sure that it has been set based on the firing
rate required of the burner;
c the burner firing system, to make sure that it is supplied for the desig-
ned fuel type;
d the fuel supply pressure, to make sure that it is included in the range
shown on the rating plate;
e the fuel supply system, to make sure that the system dimensions are
adequate to the burner firing rate, and that the system is equipped with
all the safety and control devices required by the regulations in force.
When the burner is to remain idle for some time, the fuel supply tap or
taps should be closed.
SPECIAL INSTRUCTIONS FOR USING GAS
Have qualified personnel inspect the installation to ensure that:
a the gas delivery line and train are in compliance with the regulations
and provisions in force;
b all gas connections are tight;
c the boiler room ventilation openings are such that they ensure the air
supply flow required by the current regulations, and in any case are
sufficient for proper combustion.
Do not use gas pipes to earth electrical equipment.
Never leave the burner connected when not in use. Always shut the
gas valve off.
In case of prolonged absence of the user, the main gas delivery valve
to the burner should be shut off.
Precautions if you can smell gas
a do not operate electric switches, the telephone, or any other item likely
to generate sparks;
b immediately open doors and windows to create an air flow to purge the
room;
c close the gas valves;
d contact qualified personnel.
Do not obstruct the ventilation openings of the room where gas
appliances are installed, to avoid dangerous conditions such as the
development of toxic or explosive mixtures.
DIRECTIVES AND STANDARDS
Gas burners
European directives
-Regulation 2016/426/UE (appliances burning gaseous fuels)
-2014/35/UE (Low Tension Directive)
-2014/30/UE (Electromagnetic compatibility Directive)
-2006/42/EC (Machinery Directive)
Harmonized standards
-UNI EN 676 (Automatic forced draught burners for gaseous fuels)
-EN 55014-1 (Electromagnetic compatibility- Requirements for house
hold appliances, electric tools and similar apparatus)
-EN 60204-1:2006 (Safety of machinery – Electrical equipment of
machines.)
-CEI EN 60335-1 (Specification for safety of household and similar
electrical appliances);
-CEI EN 60335-2-102 (Household and similar electrical appliances.
Safety. Particular requirements for gas, oil and solid-fuel burning
appliances having electrical connections).
-UNI EN ISO 12100:2010 (Safety of machinery - General principles for
design - Risk assessment and risk reduction);
Light oil burners
European directives
-2014/35/UE (Low Tension Directive)
-2014/30/UE (Electromagnetic compatibility Directive)
-2006/42/EC (Machinery Directive)
Harmonized standards
-UNI EN 267-2011(Automatic forced draught burners for liquid fuels)
-EN 55014-1 (Electromagnetic compatibility- Requirements for house
hold appliances, electric tools and similar apparatus)
-EN 60204-1:2006 (Safety of machinery – Electrical equipment of
machines.)
-CEI EN 60335-1 (Specification for safety of household and similar
electrical appliances);
-CEI EN 60335-2-102 (Household and similar electrical appliances.
Safety. Particular requirements for gas, oil and solid-fuel burning
appliances having electrical connections).
-UNI EN ISO 12100:2010 (Safety of machinery - General principles for
design - Risk assessment and risk reduction);
Heavy oil burners
European Directives
-2014/35/UE (Low Tension Directive)
-2014/30/UE (Electromagnetic compatibility Directive)
-2006/42/EC (Machinery Directive)
Harmonized standards
-UNI EN 267(Automatic forced draught burners for liquid fuels)
-EN 55014-1 (Electromagnetic compatibility- Requirements for house
hold appliances, electric tools and similar apparatus)
-EN 60204-1:2006 (Safety of machinery – Electrical equipment of
machines.)
-CEI EN 60335-1 (Specification for safety of household and similar
electrical appliances);
-CEI EN 60335-2-102 (Household and similar electrical appliances.
Safety. Particular requirements for gas, oil and solid-fuel burning
appliances having electrical connections).
-UNI EN ISO 12100:2010 (Safety of machinery - General principles for
design - Risk assessment and risk reduction);

4
Gas - Light oil burners
European Directives
-Regulation 2016/426/UE (appliances burning gaseous fuels)
-2014/35/UE (Low Tension Directive)
-2014/30/UE (Electromagnetic compatibility Directive)
-2006/42/EC (Machinery Directive)
Harmonized standards
-UNI EN 676 (Automatic forced draught burners for gaseous fuels)
-UNI EN 267(Automatic forced draught burners for liquid fuels)
-EN 55014-1 (Electromagnetic compatibility- Requirements for house
hold appliances, electric tools and similar apparatus)
-EN 60204-1:2006 (Safety of machinery – Electrical equipment of
machines.)
-CEI EN 60335-1 (Specification for safety of household and similar
electrical appliances);
-CEI EN 60335-2-102 (Household and similar electrical appliances.
Safety. Particular requirements for gas, oil and solid-fuel burning
appliances having electrical connections).
-UNI EN ISO 12100:2010 (Safety of machinery - General principles for
design - Risk assessment and risk reduction);
Gas - Heavy oil burners
European directives:
-Regulation 2016/426/UE (appliances burning gaseous fuels)
-2014/35/UE (Low Tension Directive)
-2014/30/UE (Electromagnetic compatibility Directive)
-2006/42/EC (Machinery Directive)
Harmonized standards
-UNI EN 676 (Automatic forced draught burners for gaseous fuels)
-EN 55014-1 (Electromagnetic compatibility- Requirements for house
hold appliances, electric tools and similar apparatus)
-EN 60204-1:2006 (Safety of machinery – Electrical equipment of machi-
nes.)
-CEI EN 60335-1 (Specification for safety of household and similar electri-
cal appliances);
-CEI EN 60335-2-102 (Household and similar electrical appliances.
Safety. Particular requirements for gas, oil and solid-fuel burning
appliances having electrical connections).
-UNI EN ISO 12100:2010 (Safety of machinery - General principles for
design - Risk assessment and risk reduction);
Industrial burners
European directives
-Regulation 2016/426/UE (appliances burning gaseous fuels)
-2014/35/UE (Low Tension Directive)
-2014/30/UE (Electromagnetic compatibility Directive)
-2006/42/EC (Machinery Directive)
Harmonized standards
-EN 55014-1 (Electromagnetic compatibility- Requirements for house
hold appliances, electric tools and similar apparatus)
-EN 746-2 (Industrial thermoprocessing equipment - Part 2: Safety requi-
rements for combustion and fuel handling systems)
-UNI EN ISO 12100:2010 (Safety of machinery - General principles for
design - Risk assessment and risk reduction);
-EN 60204-1:2006 (Safety of machinery – Electrical equipment of machi-
nes.)
-EN 60335-2 (Electrical equipment of non-electric appliances for house-
hold and similar purposes. Safety requirements)
Burner data plate
For the following information, please refer to
the data plate:
burner type and burner model: must be
reported in any communication with the
supplier
burner ID (serial number): must be repor-
ted in any communication with the supplier
date of production (year and month)
information about fuel type and network
pressure
SYMBOLS USED
Figures, illustrations and images used in this manual may differ in appearance from
the actual product.
WARNING!
Failure to observe the warning may result
in irreparable damage to the unit or
damage to the environment
DANGER!
Failure to observe the warning may result
in serious injuries or death.
WARNING!
Failure to observe the warning may result
in electric shock with lethal consequen-
ces
Type --
Model --
Year --
S.Number --
Output --
Oil Flow --
Fuel --
Category --
Gas Pressure --
Viscosity --
El.Supply --
El.Consump. --
Fan Motor --
Protection --
Drwaing n° --
P.I.N. --
BURNER SAFETY
The burners - and the configurations described below - comply with the
regulations in force regarding health, safety and the environment. For
more in-depth information, refer to the declarations of conformity that are
an integral part of this Manual.
Residual risks deriving from misuse and prohibitions
The burner has been built in order to make its operation safe; there are,
however, residual risks.
DANGER! Incorrect motor rotation can seriously
damage property and injure people.
Do not touch any mechanical moving parts with your hands
or any other part of your body. Injury hazard
Do not touch any parts containing fuel (i.e. tank and pipes).
Scalding hazard
Do not use the burner in situations other than the ones pro-
vided for in the data plate.
Do not use fuels other than the ones stated.
Do not use the burner in potentially explosive environ-
ments.
Do not remove or by-pass any machine safety devices.
Do not remove any protection devices or open the burner
or any other component while the burner is running.
Do not disconnect any part of the burner or its components
while the burner is running.
Untrained staff must not modify any linkages.
After any maintenance, it is important to restore the protec-
tion devices before restarting the machine.
All safety devices must be kept in perfect working order.
Personnel authorized to maintain the machine must always
be provided with suitable protections.
ATTENTION: while running, the parts of the burner near
the generator (coupling flange) are subject to overheating.
Where necessary, avoid any contact risks by wearing sui-
table PPE.

PART I: SPECIFICATIONS
5
Gas operation: From the supply line the gas fuel passes through the gas train (filter, safety valves, gas pressure regulator and butterfly
valve). The pressure regulator sets the gas pressure within the combustion head utilization limits. Air is supplied by a fan, which may be
onboard or separated depending on burner configuration, and is channeled through an air damper.
The air damper and the gas butterfly valve are actuated by servomotors according to load curves, in order to achieve the correct
proportion between fuel and air flows, and to optimize flue gas parameters.
The adjustable combustion head can improve the burner performance by controlling the flame geometry and combustion efficiency.
Fuel and air are routed through separated channels inside the combustion head, then mixed to ignite the flame inside the combustion
chamber. The ignition spark is provided by electrodes and a high voltage transformer (a pilot flame may also be employed, depending
on burner configuration).
Pre-ventilation of the combustion chamber is usually implemented according to gas directives.
The control panel, onboard or separated, allows the operator to monitor each operating phase.
PART I: SPECIFICATIONS
Note: the figure is indicative only
1 Control panel with startup switch
2 Combustion head adjusting ring nut
3 Electrical panel
4Cover
5 Blast tube + Combustion head
6Flange
7 Actuator
8 Silencer
9 Gas train
10 Fan motor
11 Air pressure switch
11
7
8
4
1
7
2
3
5
6
9

PART I: SPECIFICATIONS
6
Burner model identification
Burners are identified by burner type and model. Burner model identification is described as follows.
Fuel
The burner technical specifications, described in this manual, refer to natural gas (calorific net value Hi = 9,45 kWh/Stm3, density ρ=
0,717 Kg/Stm3). For different fuel such as LPG, town gas and biogas, multiply the values of flow and pressure by th corrective factors
shown in the table below.
For example, to obtain the flow and pressure values for the biogas:
Type G380A Model M-. PR. SR. *. A. 1. 65. EA.
(1) (2) (3) (4) (5) (6) (7) (8) (9)
1 BURNER TYPE G258A, G335A, G380A, G400A
2FUEL
B - Biogas,
M - Natural gas
L - LPG C - Town gas
3 OPERATION (Available versions) PR - Progressive, MD - Fully modulating
4 BLAST TUBE SR = Standard blast tube + ABS polymer (silenced) air intake
LR = Extended blast tube + ABS polymer (silenced) air intake
5 DESTINATION COUNTRY * - see data plate
6 BURNER VERSION A - Standard
Y - Special
7EQUIPMENT
0 = 2 gas valves
1 = 2 gas valves + gas proving system
7 = 2 gas valves + maximum gas pressure switch
8 = 2 gas valves + gas proving system + maximum gas pressure switch
8GAS CONNECTION 50 = Rp2 65 = DN65
80 = DN80 100 = DN100
9 MICRO-PROCESSOR CONTROL EA = micro-processor control, without inverter
EB = micro-processor control, with inverter
Fuel Hi (KWh/Stm3)ρ(kg/Stm3)fQfp
LPG 26,79 2,151 0,353 0,4
Town gas 4,88 0,6023 1,936 3,3
Biogas 6,395 1,1472 1,478 3,5
ATTENTION! The combustion head type and the settings depend on the fuel. The burner must be used only for its
intended purpose specified in the burner data plate .
ATTENTION! The corrective factors in the above table depend on the gas composition, so on the calorifc value
and the density of the gas. The above value can be taken only as reference.
Qbiogas QnaturalGas 1 478=
pbiogas pnaturalGas 35=

PART I: SPECIFICATIONS
7
Technical SpecificationsTechnical Specifications
(*) NOTE ON THE BURNER WORKING SERVICE: LMV2x automatically stops after 24h of continuous working. The device immedia-
telystarts up, automatically. LMV3x performs countinuous operation.
Gas categories and countries of application
Fuel
BURNER TYPE G258A M-.. G335A M-.. G380A M-.. G400A M-..
Output min. - max. kW 165 - 2580 280 - 3350 295 - 3800 580 - 4000
Fuel Natural gas
Category (see next paragraph)
Gas rate- Natural gas min.- max. (Stm3/h) 17,5 - 273 30 - 354 31 - 402 61 - 402
Gas pressure mbar (see Note 2)
Power supply triphase 220 V/ 230 V 3~ / 380 V/ 400 V 3N ~ 50 Hz
Auxiliary Power supply 220 V/ 230 V 2~ / 220 V / 230 V 1N ~ 50 Hz
Total power consumption kW 4,5 6 8
Electric motor kW 4,0 5,5 7,5
Protection IP40
Operation Progressive - Fully modulating
Gas train 50
Valves size / Gas connection
50 / DN50
Gas train 65 65 / DN65
Gas train 80 80 / DN80
Gas train 100 100 / DN100
Operating temperature °C -10 ÷ +50
Storage Temperature °C -20 ÷ +60
Working service Intermitent
Note1: All gas flow rates are referred to Stm3 / h (1.013 mbar absolute pressure, 15 °C temperature) and are valid for G20 gas
(net calorific value Hi = 34,02 MJ / Stm3); for L.P.G. (net calorific value Hi = 93,5 MJ / Stm3)
Note2: Maximum gas pressure = 360 mbar (with Dungs MBDLE)
= 500 mbar (with Siemens VGD or Dungs MultiBloc MBE)
Minimum gas pressure = see gas curves.
Note3: Burners are suitable only for indoor operation with a maximum relative humidity of 80 %
GAS CATEGORY COUNTRY
I2H AT, ES, GR, SE, FI, IE, HU, IS, NO, CZ, DK, GB, IT, PT, CY, EE, LV, SI, MT, SK, BG, LT, RO, TR, CH
I2E LU, PL
I2E( R ) B BE
I2EK NL
I2ELL DE
I2Er FR
DANGER! The burner must be used only with the fuel specified in the burner data
plate.
Type --
Model --
Year --
S.Number --
Output --
Oil Flow --
Fuel --
Category --
Gas Pressure --
Viscosity --
El.Supply --
El.Consump. --

PART I: SPECIFICATIONS
8
Overall dimensions (mm)
BS = standard blast tube BL = long blast tube DN = gas valves size
B*: SPECIAL blast tube lengths must be agreed with Cib Unigas
TIPO DN A
(AS) AA AD AN AP B (BS) BB C CC DEFGHJ K L M N O min
O
max P Q R S U V W Y Z
G258A
50
1340
181 35
550 100
460
391 880
509
1116 725
391
254
347
450
380 518 M12 453 300 340 320
533
148
384 624 190
708
210
190
65 564 117 1362 971
447
636 487 845 292
80 579 132 1393 1002 687 538 875 310
100 592 145 1476 1085 791 642 942 353
G335A
50
1456
550 100
399
996
1139 725
414
450 533 384 624 190
65 564 117 1385 971
447
636 487 845 292
80 579 132 1416 1002 687 538 875 310
100 592 145 1499 1085 791 642 942 353
G380A
50
1483
550 100
487
1139 725
265
450 533 384 624 190
228
65 564 117 1385 971
447
636 487 845 292
80 579 132 1416 1002 687 538 875 310
100 592 145 1499 1085 791 642 942 353
G440A
50
1496
550 100
500 471
1139 725
304
450 533 384 624 190
65 564 117 1385 971
447
636 487 845 292
80 579 132 1416 1002 687 538 875 310
100 592 145 1499 1085 791 642 942 353
ØH
P
P
N
12M
D
A (AS - AL )
B (BS - BL )
AA
R
Q
S
V
APJ
AN
AD
C
O max
O min
Omax
Omin
K
K
W
CC
E
U
BB
F
LZ
ØY
ØG
boiler recommended drilling
template
burner flange

PART I: SPECIFICATIONS
9
How to read the burner “Performance curve”
To check if the burner is suitable for the boiler to which it must be instal-
lled, the following parameters are needed:
furnace input, in kW or kcal/h (kW = kcal/h/860);
backpressure (data are available on the boiler ID plate or in the
user’s manual).
Example:
Furnace input: 600kW
Backpressure: 4 mbar
In the “Performance curve” diagram, draw a vertical line matching the
furnace input value and an horizontal line matching the backpressure
value. The burner is suitable if the intersection point A is inside the per-
formance curve.
Data are referred to standard conditions: atmospheric pressure at 1013
mbar, ambient temperature at 15° C.
Checking the proper gas train size
Performance Curves
To get the input in kcal/h, multiply value in kW by 860.
To check the proper gas train size, it is necessary to the available
gas pressure value upstream the burner’s gas valve. Then subtract
the backpressure. The result is called pgas. Draw a vertical line
matching the furnace input value (600kW, in the example), quoted
on the x-axis, as far as intercepitng the network pressure curve,
according to the installed gas train (DN65, in the example). From the
interception point, draw an horizontal line as far as matching, on the
y-axis, the value of pressure necessary to get the requested furnace
input. This value must be lower or equal to the pgas value, calcula-
ted before.
PRESSURE IN
COMBUSTION CHAMBER (mbar)
G258A M-
kW
G335A M-
kW
PRESSURE IN
COMBUSTION CHAMBER (mbar)
G380A M-
kW
G400A M-
kW
Campo di lavoro bruciatori
Tipo P60 Mod. M-xx.x.IT.A.0.50 - M-.xx.x.IT.A.0.65
-1
0
1
2
3
4
5
6
7
8
100 200 300 400 500 600 700 800 900
Potenza k W
Contropressione in camera di
combustione mbar
A
backpressure in
combustion chamber (mbar)
Power kW
0
5
10
15
20
25
100 200 300 400 500 600 700 800 900
Potenza / Output (kW)
Minima pressione gas in
rete / Minimum inlet gas
pressure (mbar)
Rp 2" (50)
DN65
Power kW
minimum gas pressure in
the network mbar
DN65

PART I: SPECIFICATIONS
10
Data are referred to standard conditions: atmospheric pressure at 1013mbar, ambient temperature at 15° C
NOTE: The performance curve is a diagram that represents the burner performance in the type approval phase or in the laboratory tests, but does not
represent the regulation range of the machine. On this diagram the maximum output point is usually reached by adjsuting the combustion head to its
“MAX” position (see paragraph “Adjusting the combustion head”); the minimum output point is reached setting the combustion head to its “MIN” position.
During the first ignition, the combustion head is set in order to find a compromise between the burner output and the generator specifications, that is why
the minimum output may be different from the Performance curve minimum
Pressure in the Network / gas flow rate curvesPerformance Curves
GAS PRESSURE mbar
G258A M-
Stm3/h
G335A M-
Stm3/h
GAS PRESSURE mbar
G380A M-
Stm3/h
G400A M-
Stm3/h
ATTENTION: the gas rate value is quoted on the x-axis, the related network pressure is quoted on the y-axis
(pressure value in the combustion chamber is not included). To know the minimum pressure at the gas train inlet,
necessary to get the requested gas rate, add the pressure value in the combustion chamber to the value read on
the y-axis.
The values in the diagrams refer to natural gas with a calorific value of 8125 kcal/Stm3 (15°C, 1013 mbar) and a density of
0.714 kg/Stm3 .
The values in the diagrams refer to GPL with a calorific value of 22300 kcal/Stm3(15°C, 1013 mbar) and a density of 2.14 kg/
Stm3. When the calorific value and the density change, the pressure values should be adjusted accordingly.
Where: Natural gas pressure shown in diagram
Real gas pressure
Natural gas flow rate shown in diagram
Real gas flow rate
Natural gas density shown in diagram
Real gas density

PART I: SPECIFICATIONS
11
Combustion head gas pressure curves
Combustion head gas pressure depends on gas flow and combustion chamber backpressure. When backpressure is subtracted, i
depends only on gas flow, provided combustion is properly adjusted, flue gases residual O2 percentage complies with “Recommended
combustion values” table and CO in the standard limits). During this stage, the combustion head, the gas butterfly valve and the
actuator are at the maximum opening. Refer to , showing the correct way to measure the gas pressure, considering the values o
pressure in combustion chamber, surveyed by means of the pressure gauge or taken from the boiler’s Technical specifications.
.
Measuring gas pressure in the combustion head
In order to measure the pressure in the combustion head, insert the pressure gauge probes: one into the combustion chamber’s
pressure outlet to get the pressure in the combustion chamber and the other one into the butterfly valve’s pressure outlet of the burner.
On the basis of the measured differential pressure, it is possible to get the maximum flow rate: in the pressure - rate curves (showed on
the next paragraph), it is easy to find out the burner’s output in Stm3/h (quoted on the x axis) from the pressure measured in the
combustion head (quoted on the y axis). The data obtained must be considered when adjusting the gas flow rate.
1
2
4
3
Note: the figure is indicative only.Key
1 Generator
2 Pressure outlet on the combustion chamber
3 Gas pressure outlet on the butterfly valve
4 Differential pressure gauge
Fig. 4
ATTENTION: THE BURNED GAS RATE MUST BE
READ AT THE GAS FLOW METER. WHEN IT IS NOT
POSSIBLE, THE USER CAN REFERS TO THE
PRESSURE-RATE CURVES AS GENERAL
INFORMATION ONLY.

PART I: SPECIFICATIONS
12
Pressure - rate in combustion head curves (natural gas)
Curves are referred to pressure = 0 mbar in the combustion chamber!
Gas pressure in
combustion head
G258A M-
Stm3/h
G335A M-
Stm3/h
Gas pressure in
combustion head
G380A M-
Stm3/h
G400A M-
Stm3/h

PART II: INSTALLATION
13
MOUNTING AND CONNECTING THE BURNER
Transport and storage
If the product must be stored, avoid humid and corrosive places. Observe the temperatures stated in the burner data table at the begin-
ning of this manual. The packages containing the burners must be locked inside the means of transport in such a way as to guarantee
the absence of dangerous movements and avoid any possible damage.
In case of storage, the burners must be stored inside their packaging, in storerooms protected from the weather. Avoid humid or corro-
sive places and respect the temperatures indicated in the burner data table at the beginning of this manual.
Handling the burner
The burner is mounted on a support provided for handling the burner by means of a fork lift truck: the forks must be inserted into the A
anb B ways. Remove the stirrup only once the burner is installed to the boiler.
ATTENTION! The equipment must be installed in compliance with the regulations in force, following the manufac-
turer’s instructions, by qualified personnel. All handling operations must be carried out with appropriate
resources and qualified personnel
ATTENTION: Use intact and correctly dimensioned hoisting equipment, conforms to the local regulations and
health and safety regulations. Do not stand under lifted loads.
Packing
The burners are despatched in wooden crates whose dimensions are:
G series: 1600mm x 1000mm x 860mm (L x P x H)
Packing cases of this type are affected by humidity and are not suitable for stacking.
The following are placed in each packing case:
burner with detached gas train;
gasket or ceramic fibre plait (according to burner type) to be inserted between the burner
and the boiler;
envelope containing this manual and other documents.
To get rid of the burner’s packing, follow the procedures laid down by current laws on disposal
of materials.
WARNING! The handling operations must be carried out by specialised and trained personnel. If these
operations are not carried out correctly, the residual risk for the burner to overturn and fall down still
persists. To move the burner, use means suitable to support its weight (see paragraph “Technical spec-
ifications”).
The unpacked burner must be lifted and moved only by means of a fork lift truck.
PART II: INSTALLATION
H
PL
AB

PART II: INSTALLATION
14
Fitting the burner to the boiler
To install the burner into the boiler, proceed as follows:
1 make a hole on the closing door of the combustion chamber as described on paragraph “Overall dimensions”)
2 place the burner to the boiler: lift it up and handle it according to the procedure described on paragraph “Handling the burner”;
3 place the 4 stud bolts (5) on boiler’s door, according to the burner drilling template described on paragraph “Overall dimensions”;
4 fasten the 4 stud bolts;
5 place the gasket on the burner flange;
6 install the burner into the boiler;
7 fix the burner to the stud bolts, by means of the fixing nuts, according to the next picture.
8 After fitting the burner to the boiler, ensure that the gap between the blast tube and the refractory lining is sealed with appropriate
insulating material (ceramic fibre cord or refractory cement).
Matching the burner to the boiler
The burners described in this manual have been tested with combustion chambers that comply with EN676 regulation and whose
dimensions are described in the diagram . In case the burner must be coupled with boilers with a combustion chamber smaller in
diameter or shorter than those described in the diagram, please contact the supplier, to verify that a correct matching is possible, with
respect of the application involved. To correctly match the burner to the boiler verify the type of the blast tube . Verify the necessary
input and the pressure in combustion chamber are included in the burner performance curve; otherwise the choice of the burner must
be revised consulting the burner manufacturer. To choose the blast tube lenght follow the instructions of the boiler manufacturer. In
absence of these consider the following:
Cast-iron boilers, three pass flue boilers (with the first pass in the rear part): the blast tube must protrude no more than Dist = 100
mm into the combustion chamber. (please see the picture below)
Pressurised boilers with flame reversal: in this case the blast tube must penetrate Dm 50 ÷ 100 mm into combustion chamber in
respect to the tube bundle plate.(please see the picture below)
The length of the blast tubes does not always allow this requirement to be met, and thus it may be necessary to use a suitably- sized
spacer to move the burner backwards or to design a blast tube tha suites the utilisation (please, contact the manifacturer).
WARNING! Carefully seal the free space between blast tube and the refractory lining with ceramic fibre rope or
other suitable means.
4
1
2
345
6
7
6
Keys
1 Burner
2 Fixing nut
3 Washer
4 Sealing gasket
5 Stud bolt
7 Blast tube
Dist. = 100 mm
DM = 50 ÷ 100 mm
A
BB
A
Dist. DM
A: ceramic fibre
B: refractory wall

PART II: INSTALLATION
15
GAS TRAIN CONNECTIONSThe diagrams show the components of the gas train included in the delivery and which must be
fitted by the installer.The diagrams are in compliance with the current laws.
Procedure to install the double gas valve unit:
two (2) gas flanges are required; they may be threaded or flanged depending on size
first step: install the flanges to prevent entry of foreign bodies in the gas line
on the gas pipe, clean the already assembled parts and then install the valve unit
check gas flow direction: it must follow the arrow on the valve body
VGD20: make sure the O-rings are correctly positioned between the flanges and the valve
VGD40 and MBE: make sure the gaskets are correctly positioned between the flange
fasten all the components with screws, according to the following diagrams
make sure bolts on the flanges are properly tightened
To mount the gas train, proceed as follows:
NOTE: the bellows unit, the manual cutoff valve and the gaskets are not part of the standard supply
WARNING: before executing the connections to the gas pipe network, be sure that the manual cutoff valves are
closed.
ATTENTION: it is recommended to mount filter and gas valves to avoid that extraneous material drops inside the
valves, during maintenance and cleaning operation of the filters (both the filters outside the valves group and the
ones built-in the gas valves).
ATTENTION: once the gas train is mounted, the gas proving test must be performed, according to the procedure
set by laws in force.
1
-
In case of threaded joints: use proper seals according to the gas used- in case of flanged joints: place a gasket between the ele-
ments
2Fasten all the items by means of screws, according to the diagrams showed, observing the mounting direction for each item
Keys
1A..1E Gasket
2 Gas filter
3 Gas valves group
4 Bellows unit
5 Manual valve
”direction” arrows for installation gas supply network
Note: the figure is indicative only
1A
1B
1C
1D
1E
2
4
5
3

PART II: INSTALLATION
16
GAS TRAIN CONNECTIONS
The diagrams show the components of the gas trai included in the delivery and which must be fitted by the installer.The diagrams are in
compliance with the current laws.
Gas train with valves group VGD and MBE with built-in gas pressure governor + gas leakage pressure switch (PGCP)
Legend
1 Filter 6 Butterfly valve
2 Pressure switch - PGMIN 7 Pressure transducer
3 Safety valve with built in gas governor 8 Main burner
4 Proving system pressure switch - PGCP 9 Antivibration joint (*optional)
5 Pressure switch PGMAX: mandatory for MBE, optional for VGD and MB-DLE 10 Manual valve(*optional)
M
PS PSLPSH
PT
7
MBE 1910
M
PS PSL PSH
VGD 1910
gas inlet gas inlet
supplied by burner constructor
by others

PART II: INSTALLATION
17
MultiBloc MB-DLE - Assembling the gas train
MULTIBLOC DUNGS
MB-DLE 405..412
MB-DLE 415..420
Mounting
1 Mount flange onto tube lines: use appropriate sealing agent
2 Insert MB-DLE: note position of O rings
3 Remove MultiBloc between the threaded flanges
4 After installation, perform leakage and functional test
5 Disassembly in reverse order
Keys
1 Gasket
2 Gas filter
3 Gas valves group
4 Bellows unit
5 Manual valve
”direction” arrows for
installation gas supply network
1
5
1
4
1
2
1
3
1
Note: the figure is indicative only
A B
MB-DLE 405..412
A
B
C
D
MB-DLE 415..420 MOUNTING POSITIONS

PART II: INSTALLATION
18
MultiBloc MBE
Threaded train with MultiBloc MBE - Mounting
ATTENTION: once the gas train is mounted according, the gas proving test mus be performed, according to the
procedure set by the laws in force.
ATTENTION: it is recommended to mount filter and gas valves to avoid that extraneous material drops inside the
valves, during maintenance and cleaning operation of the filters (both the filters outside the valves group and the
ones built-in the gas valves).
WARNING: Slowly open the fuel cock to avoid breaking the pressure regulator.
ALLA V. FARFALLA
GAS BRUCIATORE ø185 501939
PGMAX
PGCP
PGMI
EV1
EV2
S
EV2
EV1
PGMAX
PGMIN
VD-R
PGCP
VD-V
VD-V VD-R
PS
PS pressure sensor
Gas filter
Example of gas train MBE
A
A
C
B
B
C
1. Mount flange into pipe systems. Use appropriate sealing agent.
2. Insert VB together with supplied O-rings.
Check current position of O-rings.
3. Tighten supplied screws (8xM8x30) in accordance with section 8.
4. Screws (4xM5x25) for VD assembly are supplied.
5. After installation, perform leakage and functional test.
6. Disassembly in reverse order.
1. Insert studs A.
2. Insert seals B.
3. Insert studs C.
4. Tighten studs in accordance with section 8.
Ensure correct position of the seal!
5. Perform leak and functional tests after mounting.
6. Screws (4xM5x20) for VD assembly are supplied.
A
A
VDRVD-V
VB
Mounting position MBE / VB / VD

PART II: INSTALLATION
19
Mounting VD-R & PS-...
1. Gas pressure regulation is possible with VD-R and PS pressure sensor only.
WARNING! For US/CN installation, the output pressure must be monitoried by min. and max. pressure switches set
to +/- 20% of the setpoint.
2. Mounting on pipe. Sensor position: 5x DN according to MBE. Pipe fitting with female thread size ¼, mount sensor with
seal, observe torque.
3. The pressure sensor includes a vent limiter according to UL 353 and ANSI Z21.18/CSA 6.3. No venting required in loca-
tions where vent limiters are accepted by the jurisdiction.
4. Only PS pressure sensors specified by DUNGS are authorised to be connected to the VD-R‘s M12 interface.
5. Only PS cables specified by DUNGS are authorised to be used to connect the PS to the VD-R. Max. cable length 3 m.
ActuatorVD-R
The actuator VD-V does not need any adjustment (funzione ON-OFF)
The actuator VD-R It must be combined with the PS sensor (include
regolatore di pressione)
ActuatorVD-V
M12 x 5 Pin
VD-R + PS

PART II: INSTALLATION
20
Siemens VGD20.. e VGD40..
Siemens VGD20.. and VGD40.. gas valves - with SKP2.. (pressure governor)
- Connect the reference gas pipe (TP in figure; 8mm-external size pipe supplied loose), to the gas pressure nipples placed on the gas
pipe, downstream the gas valves: gas pressure must be measured at a distance that must be at least 5 times the pipe size.
- Leave the blowhole free (SA in figure). Should the spring fitted not permit satisfactory regulation, ask one of our service centres for a
suitable replacement.
version with SKP2 (built-in pressure stabilizer)
Caution: the SKP2 diaphragm D must be vertical
WARNING: removing the four screws BS causes the device to be unserviceable!
SA
SA
TP
D
= BS
SKP1. SKP2.
*** *
*
*
*
*
*
SIEMENS VGD..
Mounting positions
TP
Siemens VGD... con SKPx Example of gas train
Gas filter
T
VR
Performance range (mbar)
neutral yellow red
Spring colour SKP 25.0 0 ÷ 22 15 ÷ 120 100 ÷ 250
Spring colour SKP 25.4 7 ÷ 700 150 ÷ 1500
Siemens VGD valves with SKP actuator:
The pressure adjusting range, upstream the gas valves group,
changes according to the spring provided with the valve group.
To replace the spring supplied with the valve group, proceed as fol-
lows:
- Remove the cap (T)
- Unscrew the adjusting screw (VR) with a screwdriver
- Replace the spring
Stick the adhesive label for spring identification on the type plate.