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Building Technologies
Basic Documentation LMV27...
CC1P7541en
10 Electronic air-fuel ratio control
17.12.2018
10
Electronic air-fuel ratio control
10.1 General
Electronic air-fuel ratio control is used to control the burner’s actuators depending on
burner output. It is possible to connect 2 actuators.
Resolution is 0.1° with the actuators. Output can be regulated in increments of 0.1% in
modulating mode and with a maximum of 3 stages in multistage mode.
To reduce the electric power required for the actuators, they are never operated
simultaneously, but in successive order, or alternately.
10.2 Behavior outside the operating positions
Outside their operating positions, the actuators approach the different positions in
successive order.
The program phase determines the position to be approached.
10.2.1 Traveling speed
The running speed of the actuators is fixed at 5 seconds for a positioning angle of 90°
for SQM33.4, SQM33.5, and SQN1.
The speed is 10 seconds for a positioning angle of 90° for SQM33.6.
The SQM33.7 requires 17 seconds for a positioning angle of 90°.
The setting also applies to the running position (refer to chapter
Running position
).
10.2.2 Home
position
This position is approached in the
Home run
(10),
Standby
(12) and
Lockout position
(00) phases.
The position can be set via the following parameters:
Parameter Actuator
501.00
Home position fuel actuator
502.00
Home position air actuator
10.2.3 Prepurging
This position is approached in phase
Traveling to prepurging
(24).
The position can be set via the following parameters:
Parameter Actuator
501.01
Prepurge position fuel actuator
502.01
Prepurge position air actuator
No. Parameter
222
Gas: Prepurging
0 = inactive
1 = active
262
Oil: Prepurging
0 = inactive
1 = active