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OPERATION DESCRIPTION WITH GASE-
OUS FUEL
Switching on the switch "1", if the thermostats are on, voltage re-
aches the control box (LED 2 switches on) which starts operating.
Then the fan motor is activated (LED 3) in order to carry out the
pre-ventilation of the combustion chamber, at the same time the
servomotor commanding the air damper is moved to the opening
position corresponding to the set maximum power.
At the end of the preventilation stage the air damper goes back to
the 1st flame position. If the air ventilation control pressure switch
has found that there is sufficient pressure, the ignition transformer
(LED 5) will come on, and two seconds later the safety and main
gas valves will open.
In particular:
•
The main valve is a slow opening single-stage valve
•
The safety valve is an ON/OFF valve
•
The air damper is activated by a dedicated electric servomotor,
keep in mind that when the burner is locked out because the
thermostat is tripped, the servomotor returns the air damper to
the closed position.
The presence of the flame, detected by the control device, permi
-
ts continuation and completion of ignition, turning off the ignition
transformer.
If there is no flame, the apparatus shut down in “safety lock-out”
mode (lock warning light 7) within three seconds of the opening
of the main valve. In safety lock-out mode the valves are closed
again immediately. To release the equipment from this safety po-
sition, press button "8" on the control panel.
MODULATION OPERATION DESCRIPTION
When the burner is on at minimum flow rate, if the modulation
probe allows it (set to a temperature or pressure value higher than
that in the boiler) the air/gas regulation servomotor starts turning;
• in a clockwise direction the air flow increases;
• anticlockwise rotation: the air flow decreases.
thus gradually increasing gas supply and combustion air until the
maximum supply level set for the burner is reached.
The burner remains in the maximum flow position until the tem
-
perature or pressure is high enough to trip the modulation probe,
which reverses the rotation of the air adjustment servomotor.
The inverse rotation and therefore the air and gas supply reduction
occurs shortly thereafter.
With this procedure, the modulation system attempts to balan-
ce the amount of heat supplied to the boiler with respect to the
amount the boiler releases for use.
The modulation probe installed on the boiler measures any varia-
tion requests and automatically adjusts fuel and combustion air
supply, by starting the air/gas regulation servomotor and increa-
sing or reducing rotation as necessary.
If the limit value (temperature or pressure) at which the stop devi-
ce is set (thermostat or pressure switch) is reached even with gas
supply at minimum level, the burner is shut down by the device.
When temperature or pressure returns below the shut-down devi-
ce tripping value, the burner is activated once again according to
the program described in the previous section.
1 ON / OFF main switch.
2 Fuel switch.
3 Liquid fuel operation warning light.
5 Gaseous fuel operation warning light.
4 Equipment shut-down warning light.
6 1st stage operation indicator light
7 Control box lock-out indicator light
8 Control box reset button
9 Fuel fill button
10 Fuel selector switch
3 6
4
5
2
7
9
1
8
10
Displa
y_TBML_80pn
Summary of Contents for TBML 50MC
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