Unigas R75A, Installation, Use & Maintenance Manual

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PART III: OPERATION
25
Fig. 19 - Burner front panel
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
S1 Main switch
S3 Operation selector MAN - AUTO (operation in manual or automatic mode):
MIN = operation with minimum output
MAX = operation at the maximum output
A1 Burner Modulator (only on fully modulating burners)
A2 AZL..
4.3 Gas operation
z
Check that the control box is not in the lockout position; in case unlock it by pressing the relevant key (for further information on the
LMV.., see the related manual).
z
Check that the pressure switches/thermostats series enables the burner operation.
z
Check that the gas pressure is sufficient (signalled by an error code on the AZL.. display).
z
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).
z
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).
z
Few seconds after the gas valves opening, the ignition transformer is de-energised and light
B4
turns to off.
z
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).
.
I
S1
B1
B2
B3
B4
B5
G1 G2
G3
S3
RWF50.X
B
ild
1
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P
V h min s %
VSD ESC
nfo
A F
A1
A2