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Siemens Building Technologies
Electronic Air / Fuel Ratio Control System
CC1P7873.1en
HVAC Products
18 Notes on the commissioning of a burner
15.10.2002
Example:
1. Set the maximum burner output (100 %) with an O
2
value of 2 %.
The positions are: «Air_Pos» = 9.40 and «FuelPos» = 8.32 .
2. Reduce burner output to 93.7 % using the AZW....
For the moment, set «Air_Pos» = 9.40 and «FuelPos» = 8.32 for this load point.
3. Reduce «FuelPos» until the O
2
value of 3.18 % is reached (column with the O
2
setpoint of 2.00 % in the table). The O
2
setpoint is reached at «FuelPos» = 7.92.
4. Reduce «Air_Pos» until the O
2
value of 2 % is reached. This is the case at
«Air_Pos» = 8.92.
5. Reduce burner output to 87.5 % using the AZW...
For the moment, set «Air_Pos» = 8.92 and «FuelPos» = 7.92 for this load point.
6. Reduce «FuelPos» until the O
2
value of 3.26 % is reached. The O
2
value is
reached at «FuelPos» = 7.18.
7. Reduce «Air_Pos» until the O
2
value of 2.2 % is reached because the level of ex-
cess air shall be higher. This is the case at «Air_Pos» = 8.40. With the next setting,
the column with the O
2
setpoint of 2.20 % applies.
8. Set the load points until the minimum output is reached, following the same proce-
dure.
9. The curvepoints below the minimum output should be interpolated and then set.
18.2 Permissible range of curvepoints
Z
End switch position «Fully closed»
A
End switch position «Fully open»
T
End switch tolerance ±200 mV
Disturb
Impact of correcting variable
MinLoad / IgnitLo Minimum load / ignition load
Load
Output signal with no correcting variable
MaxLoad
Maximum burner output
MinLoad
IgnitLo
MaxLoad
0,4
78
73
1
v0
1/
060
1
Load [%]
Disturb x MinLoad
100 %
0
100
Po
si
tio
n [V
]
Z
A
9,6
T
T
Fig. 30
Permissible range of curvepoints
Legend
