Unigas R91, Installation Manual

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PART III: OPERATION
23
4.4
AIR FLOW AND FUEL ADJUSTMENT
4.5 Adjustments - brief description
The air and fuel rates adjustments must be performed at the maximum ouptput first (“high flame”): see the LMV related manual.
z
Check that the combustion parameters are in the suggested limits.
z
Check the flow rate measuring it on the counter or, if it was not possible, verifying the combustion head pressure by means of a dif-
ferential pressure gauge, as described on par. “Measuring the gas pressure in the combustion head”.
z
Then, adjust the combustion values by setting the “gas/air” ratio” curvepoints (see the LMV related manual).
z
Set, now, the low flame output (according to the procedure described on the “Siemens LMV manual”) in order to avoid the low
flame output increasing too much or that the flues temperature gets too low to cause condensation in the chimney.
4.6 User interface
The AZL2x.. display is shown below:
The keys functions are the following:
WARNING! During commissioning operations, do not let the burner operate with insufficient air flow (danger of
formation of carbon monoxide); if this should happen, make the fuel decrease slowly until the normal
combustion values are achieved.
WARNING! the combustion air excess must be adjusted according to the values in the following chart.
Recommended combustion parameters
Fuel
Recommended (%) CO
2
Recommended (%) O
2
Natural gas 9 ÷ 10 3 ÷ 4.8
Key F
Used to adjust the “fuel” actuator position ( F uel): :
While pressing the F key, the “fuel” actuator position can be changed by means of the + and - keys.
Key A
Used to adjust the “air” actuator position ( A ir):
While pressing the A key, the “air” actuator position can be changed by means of the + and - keys.
Key F + A
While pressing the two keys contemporarly, the code message will appear: by entering the proper
password it is possible to access the Service mode.