Cooling Fan; Four-Way Valve - Sunrise Medical DeVilbiss 505DZ Service Manual

C O M P O N E N T T E S T I N G , R E P A I R & R E P L A C E M E N T

Cooling Fan

The cooling fan provides a constant air flow to cool the compressor.
A defective cooling fan may cause the compressor's internal thermo-protective device to activate and shut the compressor off.
Should this condition occur, the compressor will require several minutes for the thermo-protective device to reset.
If the cooling fan is defective, it must be replaced:
1. Ensure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets.
3. Remove the compressor.
4. Disconnect the cooling fan quick-connect terminal.
5. Note the position of the fan before removing the four retaining screws that secure the fan to the base of the unit.
6. Remove the defective fan and secure the replacement fan in position with the four retaining screws.
NOTE—When installing the fan, be sure the air flow directional arrow on the side of the fan is directed away from the compressor.
7. Reconnect the electrical connector.
8. Replace the compressor.

Four-Way Valve

The pneumatically operated four-way valve alternately distributes pressure supplied by the compressor to the two molecular sieve
beds.While one bed is being pressurized the other bed is being exhausted through the four-way valve. Exhaust gases passing through
the four-way are directed to the purge valve so they can be released from the unit.
Purge valve
Four-way valve
1/4" I.D. hose
1/8" I.D. hose
(to accumulator tank)
1/2" I.D. hose
Figure 37
41
Sieve bed test points
Manifold base