riello burners Gas3-2 Rmg PDF

Installation, use and maintenance instructions

Gas burner

CODE

MODEL

TYPE

37 521 82

GA S 3 / 2

5 21 T8 0 2915865 (0)

TECHNICAL FEATURES Thermal output

2nd stage 130 - 340 kW

Operation

Two stages, high and low flame

Fuel

Natural gas Pci 8 - 10 kWh/m3 = 7000 - 8600 kcal/m3

Minimum gas pressure

For maximum output 11.1 mbar are needed measured at the coupling with nil pressure in the combustion chamber and gas with calorific value of 8600 kcal/m3

M a x i mu m g a s p r e s s u r e

15 0 mb a r

E le c tr ica l s up p ly

Si ng l e p h a se 2 20 V + 1 0 %

Mo t o r

1. 8 5 A / 2 2 0V

Ca p a ci to r

6. 3 µ F

Ignition transfor mer

Pr ima r y : 1 . 8 A / 2 2 0 V

Absorbed electrical power

0. 4 kW

-

-

112.000 - 292.000 kcal/h

- 1 0 % ~ 6 0 Hz

S e co n d a r y : 1 x 8 kV - 3 0 mA

5 6 1  – Air damper controlling motor moto r 4

2  – Control box re-set button 3  – Fair leads

3

4  – Wiring terminal block 2

5  – Air pressure switch 6  – Gas pressure test-point

Fig. 1

1

S7512

DIMENSIONS Boiler front-plate drilling

Burner 410

160

   0    4    1    ø

185 * 320

610

   7    9    3

   5    2    6    9    1    2

   0    6    1

Rp 1 1/2 155

M10

97

S7515 D1785

S7520

*Length available with special blast tube to be separately required.

5865

1

EQUIPMENT Quantity 1 1 8 1

Burner ac accessories Fl a n g e Gasket Screws Flange gasket

FIXI NG TO THE BOILER BOILER 2

3

5

4 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.

1 S7499

A

B

GAS SUPPLY

5

7

5

10

5

4 8

3

11

2

6

9

1 - Gas pipe line 2 - Cock valve 3 - Filter 4 - Pressure stabilizer 5 - Pressure test-point 6 - Minimal gas pressure switch

7 - 1st stage gas shut off valve 8 - 2nd stage gas shut off valve 9 - Burner 10 - Gas safety shut off valve 11 - Isolator joint

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1 S7514

WORKIN WORKIN G RANGE COMBUSTION CHAMBER PRESSURE 2 nd STAGE STAGE OUTPU T (in compliance with DIN 4788)

  r   a    b   m

kW kcal/h D1788

Min. output at 1st stage: 80 kW - 69.000 kcal/h.

MI NI MU M GAS PRES PRESSURE SURE - OUTPU T Pressure: detected at the pressure test-point 6) (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 270 kW it is necessary a gas pressure of 8 mbar and the combustion head set as indicated at page 7. If the combustion chamber is pressurized at 2 mbar, the pressure detected at the test-point 6) is: 8 + 2 = 10 mbar. If this value is too high, for fo r very low gas pipework pressures, the gas gear gea r 6) (page 7) 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.

CORRELA CORRELATI TI ON BETWEEN GAS PRESSURE PRESSURE AND BU RNER OUT PUT

  r   a    b   m

kW kcal/h D1789

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BURNER ELECTRICAL ELECTRICAL WIRIN G (carried out in the factory)

D2659

KEY TO LAYOUT LAYOUT C F1 MB MV PA RMG SO SM TA TB

Capacitor Protection against radio interference Burner terminal strip Fan motor Air pressure switch Control box Ionisation probe Servomotor Ignition transformer Burner earth

ATTENTION

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.

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ELECTRICAL ELECTRICAL CONNECTI CONNECTI ONS TO TH E WIRING T ERMINAL BLOCK BLOCK (to be carried out by the installer)

KEY TO LAYOUT LAYOUT

D2660

H MB PG TB TL TR TS VS V1 V2

Remote lock-out signal Burner terminal strip Minimum gas pressure swicth Burner earth Limit control device system High-low mode load control system Safety control device system Gas safety shut off valve 1° stage gas g as shut off valve 2° stage gas g as shut off valve

NOTICE - The electric wiring carried carried out by the installer must be in compliance with the rules in force in the Country. - Leads minimal minimal section section 1 mm2. - Burners with non-stop non-stop operation. For safety safety reasons, this type of burner must be stopped 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 8 and 9.

FIXI NG OF TH E ELECTRICAL ELECTRICAL WIRES 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

: fa i r l e a d P g 1 3 .5

2

- Adj Adjus ustm tmen entt the therm rmos osta tatt

: fair fair lead lead Pg 13 13.5 .5

3

- Safety thermostat

: f a i r l e a d P g 1 3 .5

4

- Gas train

: fa i r l e a d P g 1 3 .5 , sheath ø 13

5

- 2nd stage thermostat

6/7

- Pre-sheared holes

: fa i r l e a d P g 1 3 .5 S7523

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 exchange the neutral wire wire with the phase (avoid (avoid the plug-pin connectio connection). n). - Carry out a safe safe earth earth connection. connection. - Check the stop stop of the burner, by opening the boiler thermosta thermostatt and the burner lock-out, 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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BURN ER STARTSTART-UP UP CY CLE Air-purge: Air-purge: loosen the screw placed on the minimal gas pressure switch mounted on the gas train.

Screw

Plug for pressure measure

Pressure switch

S7506

AIR PRESSURE PRESSURE SWIT CH 5 ) (fig.1) (fig.1) 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. Thereafter, turn the knob anticlockwise anti clockwise 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.

S7507

1 ÷ 10 mbar

Adjustment knob

Ignition electrode position

Probe position 2 - 4 mm

  m   m    4      3

S7524

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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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

6

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).

2

5

8

Gas setting Loosen the screw 5), move the ring 6) so that the pointer 7) is coincident with the desired setpoint 8). Tighten the screw 5). S7510

Attention: Attention: the set-point number is the same for air and gas setting and is given by the following diagram.

1

3

4

7

Example: the burner is installed on a boiler of 225 kW, assuming an efficiency of 90% the burner output should be 250 kW. From the diagram it can be seen that the air and gas settings for this rating should be no. 4. kcal/h

kW

   t   u   p    t   u   o   r   e   n   r   u    B

D1793

Set-point number = for air and gas

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ADJUSTM ENT OF TH E AIR AIR DAMPER 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 1st stage.

Black lever

The black lever must anticipate the red one

Red lever

Orange lever Blue lever

Opening +

– Closing S7525

1st STAGE - Orange lever The orange lever controls the air damper position for the first flame, it is adjustable both for opening and closing. 2nd STAGE - Red and black levers The red lever controls the air damper position positi on for the second flame, it is adjustable both bot h 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

Output gas

S7526

Pre-purge

38 s

1st stage valve energizing

10 s

2nd stage valve energizing

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Time

COMBUSTION CHECKS CO 2 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 3 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.

+ L ea d

Pr ob e

S7511

BURNER START-UP Normal

Lock-out because no ignition

Thermostat Motor Ignition transf. 1st valve 1st flame 2nd valve 2nd flame Lock-out 2s

40 s

10 s

2s

D1799

If during operation the flame shuts off, lock-out occurs within 1 sec.

5865

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40 s

3 s max.

BURNER STARTIN STARTIN G DIFFICULTI DIFFICULTI ES AND T HEIR CAUSES CAUSES DIFFICULTIES

CAUSES

The burner goes through the purge period normally, the flame ignites, but the burner goes to lock-out, within two seconds after the ignition if:

The ionization probe is earthed or not in contact with the flame, or its wiring to the control box is broken, or there is a fault on its insulation to earth. The ionization current is weak (lower than 3 µA). The valve is passing too little gas (Low pressure in the gas pipework).

The burner goes to lockout, after the purge period, because the flame does not ignite; the causes may be:

The valve is defective. The pipe has not been purged from the air. The ignition arc is irregular or has failed.

The burner does not pass through the pre-purge period and the control box goes to lock-out:

The air pressure switch does not change over: it has failed or the air pressure is too low (combustion head bad set). Flame simulation exists (or the flame really lights). Gas is not supplied.

The burner does not start at the thermostat closing, because of:

The gas pressure switch does not close: incorrectly adjusted. The air pressure switch is changed over to the operational position. The fuse of the control box is broken.

The burner repeats the start-up cycle without occurring the lock-out:

This particular trouble is caused by the gas pipework pressure that is very close to the value of the gas pressure switch setting, owing to the sudden pressure decrease the valve opens and actuates only temporaneously - the opening of the pressure switch, thereafter thereafte r the valve closes, the motor stops and the pressure increases again; the pressure switch closes and the start-up start -up cycle is repeated and so forth. To prevent this trouble, setting the gas pressure switch at a lower value.

OPERAT OPERAT IN G FAULTS FAULTS Lock-out may occur, because of: - flame failure; - ionization probe earhed; - air pressure switch open. Shut-off may depend on the gas pressure switch opening.

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BURNER START START--UP CYCLE DIAGN OSTICS During start-up, indication is according to the followin table: COLOUR CODE TABLE TABLE Sequences

Colour code

Pre-purging

qqqqqqqqqqq

Ignition phase

qrqrqrqrqrq

Operation, flame ok

uuuuuuuuuu uu

Operating with weak flame signal

urururu rur

Electrical supply lower than ~ 170V

qvqvqvqvqvq

Lock-out

vvvvvvvvvv

Extraneous light Key:

vuvuvuvuvuv r

Off

q

Yellow

u

Green

v

Red

OPERATING OPERATING FAULT DIAGNOSTICS The control box has a self-diagnostic system, which easily allows identifying the operating faults ( RED LED signal). ITo use this function, wait at least ten seconds from the safety lock out, and then press the reset button for a minimum of 3 seconds. After releasing the button, the RED LED starts flashing as shown in the diagram below. RED LED on wait at least 10 s

Press button for > 3 s

Signal

Interval 3s

Signal

The pulses of the LED constitute a signal spaced by approximately approximately 3 seconds. The number of pulses will provide the information on the possible faults, according to the table below: SIG NA L

PROBABLE CAUSE

2 flashes

The flame does not stabilise at the end of the safety time:  – faulty faul ty ionisation probe;  – faulty or soiled gas valves;  – neutral/phase exchange;  – faulty ignition transformer;  – poor burner regulation (insufficient gas).

3 flashes

Min. air pressure switch does not close:  – air pressure switch faulty;  – air pressure switch incorrectly regulated;  – max. air pressure switch triggered (if installed).

4 flashes

Min. air pressure switch does not open or light in the chamber before firing:  – air pressure switch faulty;  – air pressure switch incorrectly regulated.

7 flashes

Loss of flame during operations:  – poor burner regulation (insufficient gas);  – faulty or soiled gas valves;  – short circuit between ionisation probe and earth.

8 flashes  – Not used. 10 flashes  – Wiring error or internal fault.

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RIELLO S.p.A. Via degli Alpini 1 I - 37045 Legnago (VR) Tel.: +39.0442.630111 +39.0442. 630111 Fax: +39.0442.630375 +39.0442. 630375 http:// www.rielloburners.com www.rielloburners.com

Subject to modifications