TM 5-4520-256-14
Section IV. OPERATION UNDER UNUSUAL CONDITIONS
Para.
Para.
Introduction ................................................... 2-9
Heater Operation at Elevations ......................... 2-10
2-9. INTRODUCTION. These procedures consist of operations at varying elevations.
2-10. HEATER OPERATION AT VARYING ELEVATIONS. Combustion air supply is adequate for elevations up to
6,000 ft (1829.3 m) above sea level. For operation at different elevations, it is necessary to adjust the fuel pressure as
follows (refer to Figure 2-12).
a.
Open access panel (5).
b.
Remove air filters (1).
c.
Remove hex fitting (3) from the side of fuel pump (2).
d.
Use screw driver to adjust fuel pressure by rotating screw (4). Adjust fuel pressure until heater stops smoking.
e.
Set fuel pressure for indicated elevations as shown in Table 2-4.
Table 2-4. Fuel Pressure Settings
Elevation
Fuel Pressure
Fuel Pressure
Setting at 60 Hz
Setting at 50 Hz
Sea level to 1000 ft (304.8 m)
130 - 125*
125 - 120
1000 ft (304.8 m) - 2000 ft (609.7 m)
125 - 120
120 - 115
2000 ft (609.8 m) - 3000 ft (914.6 m)
'120 - 115
115 - 110
3000 ft (914.6 m) - 4000 ft (1219.6 m)
115 - 110
110 - 100
4000 ft (1219.6 m) - 5000 ft (1524.4 m)°
110 - 100
100 - 90
5000 ft (1524.4 m) - 6000 ft (1829.3 m)
100 - 90
90 - 80
* Factory Setting
2-25
