Unigas C85A, Manual Of Installation - Use - Maintenance

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PART III: OPERATION
25
Gas operation

Turn to the ON position the mains switch S1 on the burner front panel.

Check the flame control box is not in the lockout position (light B1 on), if necessary reset it by means of the pushbutton S2 (reset);

Check that the control thermostats or pressure switches enable the burner to operate.

Check the gas supply pressure is sufficient (light G3 on), if necessary, adjust the pressure switches.
Only burners provided with the gas proving system: the check cycle of the gas proving system starts; the end of this check is
signalled by the light of the lamp on the device. When the valves check is finished, the startup cycle of the burner begins. In the case of
a leak in a valve, the gas proving system locks and the lamp G4 lights. To reset the device press the device pushbutton.

The startup cycle begins, the actuator drives the air damper to the maximum opening position, the fan motor starts and the pre-pur-
gue phase begins. During the pre-purgue phase, the complete opening of the air damper is signalled by the lamp B2 on the frontal
panel of the electrical board.

At the end of the pre-purgue phase, the air damper goes to the ignition position, the ignition transformer turns on (signalled by the
lamp B4) and few seconds later the solenoid valves EV1 and EV2 are energized (lights G1 and G2 on the front panel).

Few seconds after the opening of the valves, the ignition transformer turns off and the lamp B4 turns off subsequently:
Double-stage burners: the burner is on in low flame stage (light G is on); some seconds later, the high flame operation begins and the
burner switches automatically to high flame (light B2 is on) or remains in low flame operation, accordign to the plant requests.
Progressive and fully modulating burners - few seconds after the gas valve opening, the ignition transformer is de-energized. The
burner is in low flame operation and some seconds later, the two-stages operation begins; the burner increases or decreases its output,
directly driven by the external thermostat (progressive version) or by the modulator (fully modulating burners only).
Fig. 4 - Burner front panel
Gas operation

Turn to the ON position the mains switch S1 on the burner front panel.

Check the flame control box is not in the lockout position (light B1 on), if necessary reset it by means of the pushbutton S2 (reset);

Check that the control thermostats or pressure switches enable the burner to operate.

Check the gas supply pressure is sufficient (light G3 on), if necessary, adjust the pressure switches.
Only burners provided with the gas proving system: the check cycle of the gas proving system starts; the end of this check is
signalled by the light of the lamp on the device. When the valves check is finished, the startup cycle of the burner begins. In the case of
a leak in a valve, the gas proving system locks and the lamp G4 lights. To reset the device press the device pushbutton.

The startup cycle begins, the actuator drives the air damper to the maximum opening position, the fan motor starts and the pre-pur-
gue phase begins. During the pre-purgue phase, the complete opening of the air damper is signalled by the lamp B2 on the frontal
panel of the electrical board.

At the end of the pre-purgue phase, the air damper goes to the ignition position, the ignition transformer turns on (signalled by the
lamp B4) and few seconds later the solenoid valves EV1 and EV2 are energized (lights G1 and G2 on the front panel).

Few seconds after the opening of the valves, the ignition transformer turns off and the lamp B4 turns off subsequently:
Double-stage burners: the burner is on in low flame stage (light G is on); some seconds later, the high flame operation begins and the
burner switches automatically to high flame (light B2 is on) or remains in low flame operation, accordign to the plant requests.
Progressive and fully modulating burners - few seconds after the gas valve opening, the ignition transformer is de-energized. The
burner is in low flame operation and some seconds later, the two-stages operation begins; the burner increases or decreases its output,
directly driven by the external thermostat (progressive version) or by the modulator (fully modulating burners only).
S1
B1
S2
B2 B3
B4
B5
G1
G2 G3
S3
Keys
B1 Lock-out LED
B2 Hi-flame operation LED
B3 Lo-flame operation LED
B4 “Ignition transformer operation” LED
B5 “Fan motor overload tripped” LED
G1 “EV2 opening” LED
G2 “EV1 opening” LED
G3 “Gas pressure switch signal ” LED
G4 Gas proving system lockout signalling LED
S1 Main switch
S2 Reset pushbutton for control box
S3 Operation selector MAN - AUTO (operation in manual
or automatic mode):
MIN = operation with minimum output
MAX = operation at the maximum output
G4