Desa D20H - Manual (Page 12)

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PORTABLE FORCED AIR HEATERS
D20H, D30H AND D44H MODELS
PUMP ROTOR
(Procedure if Rotor is Binding)
1. Remove upper shell (see page 8).
2. Remove filter end cover screws using
5/16" nut-driver.
3. Remove filter end cover and air filters.
4. Remove pump plate screws using 5/16"
nut-driver.
5. Remove pump plate.
6. Remove rotor, insert, and blades.
7. Check for debris in pump. If debris is
found, blow out with compressed air.
8. Install insert and rotor.
9. Check gap on rotor. Adjust to .076/.101
mm (.003"/.004") if needed (see Fig-
ure 25).
Note: Rotate rotor one full turn to ensure
the gap is .076/.101 mm (.003"/.004") at
tightest position. Adjust if needed.
10. Install blades, pump plate, air filters,
and filter end cover.
11. Replace fan guard and upper shell.
12. Adjust pump pressure (see page 10).
Note: If rotor is still binding, proceed as
follows.
13. Perform steps 1 through 6 above.
14. Place fine grade sandpaper (600 grit)
on flat surface. Sand rotor lightly in
“figure 8” motion four times (see Fig-
ure 26).
15. Reinstall insert and rotor.
16. Perform steps 10 through 12 above.
Figure 23 - Rotor Location, D20H Model
Figure 24 - Rotor Location, D30H and D44H Models
Insert
Blade
Rotor
Pump
Plate
Air Intake Filter
Air Output
Filter
Pump
Plate
Insert
Rotor
Blade
Filter End
Cover
Air
Intake
Filter
Air Output
Filter
Fan Guard
Fan Guard
Filter End
Cover
Figure 26 - Sanding Rotor
Figure 25 - Gap Adjusting Screw Locations
SERVICE
PROCEDURES
Continued
Gap Adjusting
Screw
Gap Adjusting
Screw
Blade
.076/.101 mm (.003"/.004") Gap
Measured With Feeler Gauge
Rotor
Sandpaper