CleaverBrooks CBEX-DE, Operation And Maintenance

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Preparations for Startup
3-14
750-392
CBEX-DE
The stop screw in the rotary air damper limits damper travel at both closed (low-fire) and fully opened (high-fire)
positions. The screw is provided so that it is possible to tell, even with the burner in place, whether the damper
rotor is in fully opened or closed position. Rotating the damper counterclockwise (viewed from in front) to the
stop screw closes the damper. Rotating the damper clockwise to the stop screw opens the damper.
The amount of angular movement controlling the rate of air flow is determined by the location of the ends of the
rotary air damper rod in both the jackshaft arm and the air damper arm. Make initial settings as described in the
diagrams below. Proper settings will ensure that the angular movement of the damper starts slowly, increasing in
rate as the high fire position is approached.
3.10.1 — Initial Settings
1.
With the air damper in the fully closed position, set jack shaft air damper control arm to the settings shown in
the table below.
2.
All angles shown in the table are taken from the horizontal plane.
3.
When connecting linkage to the control arms, adjust linkage as necessary to achieve desired excess air levels
at low fire.
4.
Detach IFGR drive linkage from jack shaft and re-attach to proximity switch bracket for firing fuel oil.
5.
With the IFGR valve in the closed position, adjust the fixed ball stud quick disconnect on the proximity switch
bracket.
6.
When setting the angle on the gas valve, make sure the arm is resting against and is in line with the stop bar.
FIGURE 3-4. Rotary Air Damper