Gas Operation - Unigas C70N US Manual Of Installation - Use - Maintenance

Burner front panel
A1
B4
B2 B3
B5
G1
S1

Gas operation

DANGER!Do not restart the burner without first inspecting the good condition of the combustion head according to the
maintenance chapter.
Check that the flame control is not in lockout position (signalling on LMV) and unlock it if necessary by pressing the dedicated but-

ton (for further information on the LMV.., see the relevant manual).
In the event of a burner blockage, always check that the pilot light (B6) for flame return blockage is off. If the light is on, it means

that the photocell has detected a flame inside the combustion head mesh.
In order to unlock the burner after a flame backfire warning lockout, it is necessary to switch off the power to the control panel

(necessary before inspecting the combustion head), wait a few seconds and then switch the power back on.
Finally, press the burner unlock button (S2).

Check that the gas pressure is sufficient (indicated by an error code on the AZL..display and PGMIN light on).

Verify that the set of pressure switches or thermostats gives operating consent to the burner.

Burners fitted with gas proving system: the gas proving system test begins; when the test is performed the proving system LED

turns on. At the end of the test, the burner staring cycle begins: in case of leakage in a valve, the gas proving system stops the bur-
ner and the lamp B1 turns on.
At the beginning of the start-up cycle, the actuator drives the air damper to the maximum opening position, then the fan motor

starts up: the pre-purge phase begins. During the pre-purge phase, the air damper complete opening is signalled by the light B2 on
(see front panel).
At the end of the pre-purge, the air damper is driven to the ignition position, the ignition transformer is energised (signalled by the

light B4 on the front panel) then, few seconds later, the EV1 and EV2 gas valves are energised (light G1 and G2 on the front
panel).
Few seconds after the gas valves opening, the ignition transformer is de-energised and light B4 turns to off.

.The burner operates in the low flame stage; few seconds later the two-stages operation begins and the burner output increases or

decreases, driven by the external thermostats (progressive burners) or by the modulator (fully-modulating burners).
PART IV: OPERATION
B1
A2
B2
B3
B4
B5
G1
G2
G3
S1
S2
S3
G3
G2
A1
A2
B6
B1
S3
S2
Keys
Lock-out LED
Hi-flame operation LED
Lo-flame operation LED
"Ignition transformer operation" LED
"Fan motor overload tripped" LED
"EV2 opening" LED
"EV1 opening" LED
"Gas pressure switch signal " LED
Main switch
Reset pushbutton for control box
Operation selector MAN - AUTO (operation in manual or automatic
mode):
MIN = operation with minimum output
MAX = operation at the maximum output
Burner Modulator (only on fully modulating burners)
AZL..
28