Riello GAS 4/2 Specification sheet

Installation, use and maintenance instructions
2915866 (4) - 07/2015
Forced draught gas burner
Two stage operation
CODE MODEL TYPE
3752282 GAS 4/2 522 T80
GB

Declaration of conformity in accordance with ISO / IEC 17050-1
Manufacturer: RIELLO S.p.A.
Address: Via Pilade Riello, 7
37045 Legnago (VR)
Product: Forced draught gas burner
Model: GAS 4/2
These products are in compliance with the following Technical Standards:
EN 676
EN 12100
and according to the European Directives:
MD 2006/42/EC Machine Directive
LVD 2006/95/EC Low Voltage Directive
EMC 2004/108/EC Electromagnetic Compatibility
The quality is guaranteed by a quality and management system certified in accordance with UNI EN ISO 9001.
Legnago, 21.05.2015 Executive General Manager
RIELLO S.p.A. - Burner Department Research & Development Director RIELLO S.p.A. - Burner Department
Mr. U. Ferretti Mr. F. Comencini

5866
1
TECHNICAL DATA
BURNER DESCRIPTION
OVERALL DIMENSIONS
Thermal output 2
nd
stage 180 - 470 kW - 154.800 - 404.200 kcal/h
Operation Two stages, high and low flame
Fuel Natural gas Pci 8 - 10 kWh/m
3
= 7000 - 8600 kcal/m
3
Minimum gas pressure For maximum output 9.8 mbar are needed measured at the coupling with nil pressure in the combustion chamber and gas with calorific value of
8600 kcal/m
3
Maximum gas pressure 150 mbar
Electrical supply Three phase 380 V + 10% - 10% ~ 60Hz with neutral
Motor 1.5A / 380V
Ignition transformer Primary: 1.8A / 220V - Secondary: 1 x 8 kV - 30 mA
Absorbed electrical power 0.6 kW
1– Air damper controlling motor
2– Control box re-set button
3– Fair leads
4– Wiring terminal block
5– Re-set push-button of the
motor overload relay
6– Air pressure switch
7– Gas pressure test-point Fig. 1
6
3
4
5
2
1
S7530
7
Boiler front-plate
drilling
* Length available with special blast tube to be separately required.
Burner
160
160
165 M10
410 610187
*
320
397
97
292
165
ø 150
Rp 1 1/2
S7515 S7520
D1785

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STANDARDS EQUIPMENT
ACCESSORIES
• RADIO DISTURBANCE PROTECTION KIT code 3010386
If the burner is installed in places particularly subject to radio disturbance (emission of signals exceeding 10
V/m) owing to the presence of an INVERTER, or in applications where the length of the thermostat
connections exceeds 20 metres, a protection kit is available as an interface between the control box and the
burner.
FIXING TO THE BOILER
GAS SUPPLY
Quantity Description
1 Flange
1 Gasket
8 Screws
1 Flange gasket
Separate the combustion head from the
burner body by loosening the screws 1)
and 2) and withdrawing the group A) from
the holding bars 3).
Fix the group B) to the boiler front plate 4)
using the gasket 5) provided as accessory.
2 3 5 4
1
A B
S7499
5
10
8 11 5
94 3 12 2 1
S7534
5
6
1- Gas pipe line 7- Gas safety shut off valve
2- Cock valve 8- 1
st
stage gas shut off valve
3- Filter 9- 2
nd
stage gas shut off valve
4- Pressure stabilizer 10 - Burner
5- Pressure test-point 11 - Gas leak control device
6- Minimal gas pressure switch 12 -Isolator joint
7

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WORKING RANGE
COMBUSTION CHAMBER PRESSURE 2nd STAGE OUTPUT
(in compliance with DIN 4788)
Min. output at 1
st
stage: 115 kW - 99.000 kcal/h.
MINIMUM GAS PRESSURE - OUTPUT
Pressure: detected at the pressure test-point 7) (fig. 1) with nil mbar into the combustion chamber.
Should the combustion chamber be pressurized, the pressure necessary will be that of the
graph plus the pressurization value.
Example: to obtain 350 kW it is necessary a gas pressure of 7 mbar and the combustion head set
as indicated at page 8.
If the combustion chamber is pressurized at 2 mbar, the pressure detected at the test-
point 7) is: 7 + 2 = 9 mbar.
If this value is too high, for very low gas pipework pressures, the gas gear 6) (page 8)
could be more open.
Do not decrease the pressure at the coupling under the values shown in the diagram.
Output: the maximum value is obtainable with gas Pci 8600 kcal/m
3
.
CORRELATION BETWEEN GAS PRESSURE AND BURNER OUTPUT
kW
kcal/h
mbar
D1786
kW
kcal/h
mbar
D1787

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BURNER ELECTRICAL WIRING
(carried out in the factory)
CMV Fan motor contactor
F1 Protection against radio interference
K1 Relay
MB Burner terminal strip
MV Fan motor
PA Air pressure switch
RMG Control box
RT Thermal overload
SM Servomotor
SO Ionisation probe
TA Ignition transformer
TB Burner earth
KEY TO LAYOUT
A TTENTION
In the case of phase-phase feed, a
bridge must be fitted on the control box
terminal board between terminal 6 and
the earth terminal.
20107484

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ELECTRICAL CONNECTIONS TO THE WIRING TERMINAL BLOCK
(to be carried out by the installer)
NOTICE
- Theelectric wiring carried out bythe installer mustbe in compliancewith the rules in force in the Country.
- Leads minimal section 1 mm
2
.
- Burners with non-stop operation. For safety reasons, this type of burner must be stopped every 24
hours of operation, by means of an hours-counter to be connected in series with the adjustment
devices.
FLAME MODULATION
The flame modulation is obtainable through the thermostat, controlling the second valve, connected
to the terminals 10 and 11.
D2662
HRemote lock-out signal
H1 Remote lock-out signal of leak detection control device
MB Burner terminal strip
PG Minimum gas pressure swicth
TL Limit control device system
TR 2
nd
stage remote control system
TS Safety control device system
VS Gas safety shut off valve
VPS Leak detection control device
V1 1
st
stage gas shut off valve
V2 2
nd
stage gas shut off valve
XP7 Plug for leak detection control device
220V 380V
F Ampere T6 T6
S mm
2
1,5 1,5

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FIXING OF THE ELECTRICAL WIRES
All the electrical wires, which are to be connected to
the terminal block 4) (fig. 1) shall pass through the fair
leads 3) (fig. 1) as for this scheme.
1- Single phase supply : fair lead Pg 13.5
2- Adjustment thermostat : fair lead Pg 13.5
3- Safety thermostat : fair lead Pg 13.5
4- Gas train : fair lead Pg 13.5,
sheath ø 13
5-2
nd
stage thermostat : fair lead Pg 13.5
6 / 7 - Pre-sheared holes
Further prospective signals or controls can be connected to the burner wiring terminal board by
removing the metal weldnuts from the pre-sheared holes and inserting a commun fair lead for the
passage and the clamping of the leads.
NOTES
- Do not exchange the neutral wire with the phase (avoid the plug-pin connection).
- Carry out a safe earth connection.
- Check the stop of the burner, by opening the boiler thermostat and the burner lock-out, by
disconnecting the lead from the flame probe.
WARNING
When closing the burner on its slide-bars, pull towards the outside the high voltage cable and the
cable of the flame detection probe, till to little tension
BURNER START-UP CYCLE
Air-purge: loosen the screw placed on the
minimal gas pressure switch mounted on the
gas train .
AIR PRESSURE SWITCH
The air pressure switch 6)(fig. 1) setting shall
be carried out after having set all other adjust-
ments of the burner and the air pressure
switch shall be at its lowest set-point.
When the burner is operating, increase the
adjustment pressure by turning - slowly -
clockwise the knob till reaching the burner
lock-out.
Thereafter, turn the knob anticlockwise for 1
mbar and repeat the burner start-up for
checking the regularity: if lock-out intervenes
turn the knob anticlockwise for 0.5 mbar.
S7523
Screw
Plug for pressure
Pressure switch
S7506
measure
1 ÷ 10
mbar
Adjustment knob
S7507

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PROBE - IGNITION ELECTRODE POSITION
CAUTION:
do not turn the ionization probe, maintain the drawing position; should it be close to the ignition
electrode, damage may occur to the control box amplifier.
COMBUSTION HEAD ADJUSTMENT
Two separate adjustments have to be made: air
and gas.
These adjustments can be carried out when
the burner is still open, during the installation
(see page 2 - Fixing to the boiler).
Air setting
Loosen the two screws 1) and move the internal
part of the combustion head 2) so that its rear
edge 3) is coincident with the desired set-point
on the plate 4). Tighten the screws 1).
Gas setting
Loosen the screw 5), move the ring 6) so that
the pointer 7) is coincident with the desired set-
point 8). Tighten the screw 5).
Attention:
the set-point number is the same for air and gas
setting and is given by the following diagram.
Example:
the burner is installed on a boil-
er of 270 kW, assuming an ef-
ficiency of 90% the burner
output should be 300 kW.
From the diagram it can be
seen that the air and gas set-
tings for this rating should be
no. 3.
3 - 4 mm
2 - 4 mm
Probe position Ignition electrode position
S7524
25681
3
4
7
S7533
kcal/h kW
Burner output
Set-point number = for air and gas
D1792

5866
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ADJUSTMENT OF THE AIR DAMPER MOTOR
STOP - Blue lever
This lever leaves the factory vertically positioned and
corresponds to the complete closing of the air damper.
A partial opening of the air damper might be obtained by
moving leftwards this lever (+ on the label).
The new position of the air damper is detectable when
the burner is off.
Do not overcome the position of the orange lever for the
1
st
stage.
The black lever must anticipate the red one.
1
st
STAGE - Orange lever
The orange lever controls the air damper position for the
first flame, it is adjustable both for opening and closing.
2
nd
STAGE - Red and black levers
The red lever controls the air damper position for the second flame, it is adjustable both for closing and
opening.
The black lever controls the opening of the second oil valve and it must always anticipate - for a bit -
the red lever, but never the orange one.
OPERATIONAL DIAGRAM
S7525
Black lever
Red lever
Orange lever
Blue lever
Opening + – Closing
S7526
Output gas
Time
Pre-purge
1
st
stage valve energizing
2
nd
stage valve energizing
38 s
10 s