Burnham LE L7248 User Manual
Page 14
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the burner output. The ZC output is energized.
The controller continues to monitor the system
and automatically restarts if the error condition
clears. Refer to Table 4.
The operating sequence for the L7248 is shown in
Table 5.
Figure 14: Setpoints and Differentials
G. HIGH LIMIT CONTROLLER
The High Limit opens and turns off the burner when
the water temperature reaches the setpoint. The
High Limit automatically resets after the water
temperature drops past the setpoint and through the
Differential. The L7248 models have High Limit
Differential presets of 15°F (8°C). See Figure 14.
6.
REMOVE GUN ASSEMBLY
LE Boilers equipped with Beckett AFG burners. Items
to be checked are nozzle size, type, and angle; head
size, (and setting on MD(V1) head); gun setting; and
positioning of electrodes. This information is shown in
Figure 15, and Table 6. If the desired boiler firing rate
is 0.6 GPH, the nozzle must be changed out, the low
firing rate baffle must be installed and the factory
settings must be changed according to Table 6. These
parts are in the bag attached to the burner. Reinstall
gun assembly.
LE Boilers equipped with Riello 40 F3 and 40 F5
burners: Items to be checked are nozzle size, type and
angle: settings (air gate, turbulator and pump pressure).
This information is shown in Table 6A. Reinstall gun
assembly.
7.
ADJUST OIL BURNER BEFORE STARTING
A. SET BURNER SETTINGS, see Tables 6 and 6A.
B. OPEN ALL OIL LINE VALVES.
Figure 1: "L1" and "V1" Head Electrode Positioning and Gun Setting (Beckett AFG)