Riello GAS 6 P/M Quick start guide

2915244 (3) - 09/2012
Installation, use and maintenance instructions
Forced draught gas burner
MODEL TYPE
GAS 6 P/M 536 T80

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ELECTRICAL DATA
Motor IE1
Motor IE2
Thermal power - Output 300 ÷ 1050 kW - 258.000 ÷ 903.000 kcal/h
Operation - two stages progressive
- modulating (kit with controller available upon request)
Fuel natural gas Pci 8 - 10 kWh/m3= 7000 - 8600 kcal/m3
Minimum gas pressure for maximum output 12.3 mbar are needed measured at the cou-
pling with nil pressure in the combustion chamber and gas with cal-
orific value of 8600 kcal/m3
Maximum gas pressure 150 mbar
Electrical supply 3N ~ 380V
60 Hz
Fan motor rpm
V
kW
A
3350
220/380
1.5
6.6 - 3.8
Ignition transformer V1 - V2
I1 - I2
220 V - 1 x 8 kV
1.8 A - 30 mA
Electrical power consumption kW max 1.7
Electrical supply 3N ~ 380V
60 Hz
Fan motor rpm
V
kW
A
3500
220/380
1.5
5.5 - 3.2
Ignition transformer V1 - V2
I1 - I2
220 V - 1 x 8 kV
1.8 A - 30 mA
Electrical power consumption kW max 1.7

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1- Servomotor controlling air and gas
2- Adjustment cam
3- Power controller (for modulating to be required
separately)
4- Control box reset button
5- Servomotor connection
6- Fair leads
7- Wiring terminal block
8- Reset push-button of the motor over load relay
9- Air pressure switch
10 - Gas pressure test-point
DIMENSIONS
* Length available with special blast tube to be separately required.
QUANTITY ACCESSORIES
1 Flange
1 Gasket
8Screws
1 Flange gasket
Fig. 1

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COMBUSTION CHAMBER PRESSURE - MAXIMUM OUTPUT
Minimum output: 300 kW - 258.000 kcal/h
MINIMUM GAS PRESSURE - OUTPUT
Pressure: detected at the pressure test-point 10) (fig. 1) with oil 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 800 kW it is necessary a gas pressure of 11 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 10) is:
11+2=13 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/m3.

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MOUNTING TO THE BOILER
Separately the blast tube from the burner body by
loosening the screws 7) and 3), fix the blast tube to
the boiler front plate 5) using the gasket 6) provided.
Insert the burner on the holding bars 4) and fasten
the screws 7) and 3).
The combustion head adjustment should be carried
out as follows: Loosen the screws 2) UNHOOK THE
TENSION ROD OF THE AIR DAMPER 1) remove
the connecting lead of the servomotor, withdraw the
group A) from the group B).
After the setting, re-assemble and verify that the
tension rod of the air damper was locked.
GAS SUPPLY
1- Gas pipe line 6- Minimal gas pressure switch
2- Cock valve 7- Safety valve
3- Filter 8- Adjustment valve
4- Pressure stabilizer 9- Adjusting throttle valve
5- Pressure test-point 10- Burner
11- Gas Leak control device

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BURNER ELECTRICAL WIRING
(carried out y the factory)
D3377

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ELECTRICAL CONNECTIONS TO THE WIRING TERMINAL BLOCK
(to be carried out by the installer)
NOTE
- The electrical wiring carried out by the installer must be in compliance with the rules in force in the Country.
- Leads minimal section 1 mm2.
- Adjustment for the motor thermal relay:
- at the beginning of the scale for 380V
- at the end of the scale for 220V
- Burners with non-stop operation. For safety reasons, this type of burner must be stopped every 24 hours of oper-
ation, by means of an hours-counter to be connected in series with the adjustment devices.
RWF 40 CONNECTION
D3378
D3379

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FIXING OF THE ELECTRICAL WIRES
All the electrical wires, which are to be connected to the terminal block 7) (fig. 1) shall pass through the fair leads 6)
(fig. 1) as per this scheme.
1- Three phase supply: fair lead Pg 21
2- Single phase supply: fair lead Pg 13.5
3- Adjustment thermostat: fair lead Pg 13.5
4- Safety thermostat: fair lead Pg 13.5
5- Gas train:fair lead Pg 13.5, sheath ø 13
6- 2nd stage thermostat:fair lead Pg 13.5
(probe for modulating version)
7- Pre-sheared hole: fair lead Pg 13.5 (for power controller - modulating version)
8- Pre-sheared holeg
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.

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START-UP
Air-purge: Loosen the screws placed on the minimal gas pressure switch mounted on the gas train.
AIR PRESSURE SWITCH
The air pressure switch setting shall be carried out after having set
all other adjustments 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.
There after, 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.
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.

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ADJUSTMENT BURNER
1 - COMBUSTION HEAD
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 3 - 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 follow-
ing diagram.
Example: The burner is installed on a boiler of 810 kW, assuming an efficiency of 90% the burner output should be
900 kW. From the diagram it can be seen that the air and gas settings for this rating should be no. 5.

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2 - SERVOMOTOR
The servomotor controls the air damper and the gas throttle valve.
It is provided with three adjustable cams controlling the related change-over switches.
1) 1st cam (blue) 6) Cam with adjustable profile
2) 2nd cam (red) 7) Adjustable profile
3) 3rd cam (black) 8) Fastening screws
4) Pointer 9) Adjusting screws
5) Motor reset button
1st cam: it controls the min. stroke and remains always positioned on 0°, in this way, when the burner is off the air
damper is totally closed.
2nd cam: it controls the max. stroke, generally it is positioned on 130°.
3rd cam: it controls the minimal modulating power.
It is set by the factory on 30°: normally this position is the most suitable for the first ignition. Thereafter the
installer may vary this setting accordingly with the installation requirements.
10) Throttle valve control sector
11) Tension rod
12) Gas adjustment shutter

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3 - COMBUSTION ADJUSTMENT (References on drawings at page 9)
For the combustion adjustment we suggest to proceed in this way:
- Let the burner starts and after the flame ignites at the minimum output, disconnect the servomotor by opening the
connection 5) (page 1) placed on panel.
- Thereafter proceed successively to the adjustment of the maximum, minimal outputs and to the intermediate
output.
3.1 - Maximum output setting
Gas
- Disjoint the cam with adjustable profile 6) from the servomotor by re-setting the button 5).
- Turn manually clockwise the cam 6) till to reach the position of 130° (on the edge of the servomotor) in
correspondence of the pointer 4). In this way the gas throttle valve 12) is at the max. opening - 90°-
- Join again the cam with adjustable profile 6) to the servomotor by pushing the button 5).
Now set the gas rate by acting on the gas setting valve.
Air
- Move the adjustable profile 7) of the cam by gradually acting on the screws 9).
3.2 - Minimal output setting
Gas
- Disjoint the cam with adjustable profile 6) by means of the button 5).
- Turn manually anticlockwise the cam till to reach the position of 30°.
- Lock it again and measure the gas rate.
If a different minimal output is desired, set free the cam with adjustable profile and turn it anticlockwise; for a higher
output turn it clockwise. When the minimal value is satisfying, set on the cam 3) the opening value signed on the
pointer 4).
Air
- Vary the profile of the cam 7) by gradually acting on the screws 9).
Be careful to not modify the part of profile controlling the air shutter at the maximum output, previously set.
3.3 - Intermediate outputs setting
Gas
No setting is required.
Air
It is carry out by acting on the screws 9) of the cam profile, being careful to not move those for the minimum and
maximum outputs.
When the combustion setting is ended re-connect the electrical wiring of the servomotor by plugging the connector
5) (page 1); then lock the screws 9) by means of the cross-screws 8).

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4 - RATIO BETWEEN THE MINIMUM AND MAXIMUM OUTPUT
(References on drawings at page 9)
For a better explanation we suppose to have a burner with an adjustable output between the range 25 - 100. The
ratio between 1 : 4 (25 - 100) and 1 : 3 (25 - 75); our burners leave the factory set for these ratio.
If the ratio should be reduced at 1 : 2 (25 - 50 or 50 - 100) it is advisable to re-adjust the tension rods for the air and
gas and the controlling sector of the gas throttle valve.
4.1 - Control of the gas throttle valve
The tension rod 11) moving the control sector of the throttle valve is positioned - by the factory - on the hole marked
90° (90° is the moving angle of the throttle valve when the cam with the adjustable profile 6) covers the complete
angle of 130°).
When the ratio between the minimum and maximum output
is approximately 1 : 2, the tension rod shall be positioned
on the hole marked 60° (60° is the moving angle of the
throttle valve when the cam covers 130°).
If the ratio 1 : 2 is in the lower outputs range (25 - 50) the
change from 90° to 60° of the tension rod will be sufficient.
Should this ratio be in higher range (50 - 100) in this case,
further to position the tension rod on 60° it shall be
shotened.
Proceed as follows:
- Disjoint the articulation from the control sector.
- Screw down the tension rod on the extension.
- Re-assemble the articulation on the control sector.
In this way the gas throttle valve - servomotor at 0° - is
partially open.
The shortening of the tension rod shall permit the gas flow
without setting the 3rd cam of the servomotor too forward,
because in this way the turn of the cam with adjustable
profile would be limited.
4.2 - Control of the air damper
The length of the tension rod 13) adjusting the air damper
can be varied too.
If the air damper is moving, during the operation, into a
reduced angle (ratio 1 : 2 lower outputs range) it is
necessary to extend the tension rod.
In this way the cam profile is not too much bent.
When the burner is off proceed in this way:
- Disjoint the articulation 14) of the tension rod 13) from the
lever 15).
- Extend the tension rod.
- Manually position the servomotor on 0°.
- Join the tension rod to the lever.
- Move the cam profile till the pointer placed on the air
damper shaft is at 0°.

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COMBUSTION CHECKS
CO2
It is advisable to not exceed 10% of CO2(gas with calorific value of 8600 kcal/m3), in order to avoid the risk that
small changes of the adjustments due, for instance, at draught variation, may cause combustion with insufficient air
and consequently formation of CO.
CO
For safety reason the value of 0.1% (one thousand p.p.m.) must not be exceeded.
IONIZATION CURRENT
The minimum current necessary for the control box operation is 6 µA.
The burner normally supplies a higher current value, so that no check is needed.
However, if a measurement of the ionization current is required, it is necessary to disconnect the probe lead and
insert a d.c. microamperometer.
Motor lock-out
This is caused by the thermal protector relay, in case of overloading, or by the lacking of the phase.
To clear, pushdown the appropriate knob, after having removed the protective cover.
BURNER START-UP
If during operation the flame shut off, lock-out occurs within 1 sec.

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OPERATION TROUBLES AND THEIR CAUSES
The symbol, visible on the reading disc of the pointer, shows the kind of problem.
The control box does not start at the thermostats closing, because of:
- lack of gas;
- the gas pressure switch does not close the contact: bad set;
- the air pressure switch changed over in operation position;
- the control box fuse is broken;
- the servomotor does not totally change over the closing circuit in being between the terminals 11 and 8 of the
control box.
Stop at the start-up, because of:
- the servomotor does not change over the max. opening circuit in being between the terminals 9 and 8 of the control
box.
PLock-out
The air pressure switch does not change over, because of:
- defective contact;
- insufficient pressure of the air.
OLock-out
Unperfect operation of the flame detecting circuit, because of:
- probe to earth;
- defective internal amplifier.
PStop during pre-purge phase, because of:
the servomotor does not change over the minimal opening circuit in being between the terminals 10 and 8 of the
control box.
1Lock-out due to flame signal lack; if:
- the ionisation probe is not inside of the flame;
- the probe connection to the control box is disconnected;
- the ionization current is insufficient (min. 6 µA).
Lock-out during operation due to:
- flame signal lack;
- no air pressure.
NOTICE
- If lock-out occurs between the start-up and pre-ignition phase without that a symbol comes out, the cause is the
flame simulation.
- If the burner repeats continuously the start-up cycle without lock-out occurring, this is due to the “oscillation” of the
gas pressure switch caused by a setting very near to the gas network pressure, therefore the pressure decreasing
at the burner start-up is sufficient to actuate the gas pressure switch causing a new start-up.

Subject to modifications
RIELLO S.p.A.
I-37045 Legnago (VR)
Tel.: [phone]
http:// www.riello.it
http:// www.rielloburners.com