Burnham SCG 1100-H4 - Manual (Page 74)

74
Figure 45: Differential Pressure Measurement
TABlE 15: DIFFERENTIAl PRESSURE SWITCh SETTINGS
E.
Main Burners and Firebox.
1. Vacuum firebox. Exercise care - do not damage base
insulation.
2. Clean main burners. Brush top of burners with soft
bristle brush. See Figure 44. Vacuum to remove any
dirt and lint.
3. Vacuum tip of pilot burner.
4. Check gas orifices for lint and dirt. Clean as
necessary.
5. Install main burners by reversing procedure to
remove burners.
a. Pilot burner must be installed in original
location. See Table 14.
b. Main burners must be properly secured in burner
tray slot at rear of firebox and over gas orifice.
See Figure 44.
c. Pilot gas supply and pilot lead wires must be
reconnected.
d. Burner access panel must be securely in place.
e. Reinstall air diffuser screen.
f. Reconnect Flame Roll-out wires.
g. Air Intake Box Front Door must be installed.
F. Check operation. Follow steps G through P from
Section VIII: System Start-up.
G.
Procedure for Measuring Differential Pressure (See
Figure 45).
1. With boiler off, remove Gray and Black Hoses at
differential pressure switch.
2. With tees and ¼ inch aluminum stubs, connect water
manometer as shown with additional tubing.
3. Start boiler and read Pressure on Manometer
when boiler water temperature reaches operating
temperature. Refer to Table 15 for minimum
readings.
NOTE: If switch drops-out before boiler reaches
temperature or if pressure differential readings are
below minimums shown in Table 15, check for
cracks in hose or contact your nearest Burnham
representative.
4. Stop boiler, remove manometer and reconnect hoses
to differential pressure switch. See Figures 42 and
45.
Boiler Model
Minimum Differential Pressure
Sea Level to 4,999 Ft. 5,000 - 10,000 Ft. Elevation
SCG-3 1.32” w.c. .80” w.c.
SCG-4 1.17” w.c. .65” w.c.
SCG-5 1.17” w.c. .65” w.c.
SCG-6 .88” w.c. .35” w.c.
SCG-7 .80” w.c. .30” w.c.
SCG-8 .88” w.c. .35” w.c.
SCG-9 .88” w.c. .35” w.c.