Printed Circuit Board (Pc Board); Rotary Valve - Sunrise Medical DeVilbiss Serie Manual De Servicio

C O M P O N E N T T E S T I N G , R E P A I R , A N D R E P L A C E M E N T
3. Use a pressure-vacuum gauge (part #PVO2D-601) and a fitting
suitable to fit on the oxygen outlet or on a short piece of tub-
ing connected to the outlet.
4. If the pressure-vacuum gauge reads anything other than 8.5 ±
.5 psi (58.6 ± 5.9 kPa) with gauge outlet blocked, adjustment
to the pressure regulator may be required. If so, call Sunrise
Service Department at 1-800-333-4000 (814-443-4881).
NOTE: Make sure no leaks exist before adjusting the
pressure regulator. by using a certified leak detection solution
such as Snoop ® or equivalent (must not contain ethylene gly-
col).
CAUTION: Do not apply leak test solution to any part
of the rotary valve or the main PC Board assembly.
A malfunction in the pressure regulator will cause either a loss
or fluctuation in the oxygen flow which will be seen on the
flow meter or a decrease in oxygen concentration.
To replace the pressure regulator (Figure 9):
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets.
3. Remove the tubing clamp and tubing from the pressure regulator.
4. Unscrew the regulator from the accumulator tank.
5. Install a new regulator on the accumulator tank and attach the
tubing and tubing clamp.
6. Replace the front and back cabinets.
PRINTED CIRCUIT BOARD
The printed circuit (PC) board is responsible for monitoring
and controlling the DeVilbiss Oxygen Concentrator.
The PC board has preset alarms for low flow and power fail-
ure. Should any of the alarm values be exceeded, the patient
alert system will activate.
NOTE: If the concentrator has been unused for an extended
period, the unit must run 20 minutes before the power fail
alarm will be enabled.This alarm is powered by a capacitor on
the PC board.
CAUTION: Do not apply any force or flex to the PC
Board when connecting or disconnecting electronic or
pneumatic components. Damage to the electronic
assembly is possible.
To remove and replace the PC board (Figure 7):
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front and back cabinets and the bib.
3. Disconnect all wires , terminals and connectors.
4. Remove the 1/8" (3.2mm) tubing attached to the sensor.
5. Remove the screw that secures the board to the unit and
remove the PC board.
6. Install the new PC board and secure it using the screw.
7. Reconnect all electrical wires, terminals, connectors and the
tubing to the sensor.
8. Replace the bib and front and back cabinets.
ROTARY VALVE (Figure 13)
The timed rotary valve alternately distributes pressure sup-
plied by the compressor to the sieve beds.While one bed is
being pressurized the other bed is being exhausted through
the valve. Exhaust gases go through the valve exhaust port and
exit through the exhaust muffler.
The valve contains two revolving discs powered by a stepper
motor to cycle the pressure between the beds. DC voltage is
supplied by the PC board to the motor windings causing the
internal discs to turn and direct pressure to the proper sieve bed.
If the rotary valve does not shift properly the same bed may
continue to pressurize causing the pressure relief valve to
release the excess pressure.
There are several reasons why the rotary valve could malfunc-
tion; therefore the cause of failure must be determined before
corrective action can be taken.
To test the rotary valve (Figures 6 & 7):
1. Remove the front cabinet.
2. Connect pressure gauges to the test points at the top of the
sieve beds in order to observe unit cycling and bed pressures.
Refer to the section on Normal Operating Sequence.
3. If it is determined that the valve did not shift properly or the
bed pressures are uneven, continue testing with step 4.
4. The stepper motor on the rotary valve has multiple windings
so there are several voltage readings that need to be checked
in order to determine if the problem is being caused by the
PC board or the valve itself.Testing for proper voltage is done
at the wire harness connectors on the valve or on the PC
Board using a voltmeter. Below are the valve voltage test posi-
tions and voltages that should be present at each one:
Negative Lead Positive Lead
Orange Yellow or White
Orange
Orange
Black or Green or Yellow or White
Red or Blue
NOTE: The 2-3 Volt reading will go on and off as the valve
cycles. 515A Series have a fixed cycle time of approximately 7
seconds. However, when the ADS model (with OSD) goes into
its "turn-down" mode, the cycle time is shortened to approxi-
mately 3 seconds.
5. If any of these readings are not obtained, check for loose or
broken wires in the harness. If wire harness is okay, replace the
main PC board.
6. If proper voltages are obtained, replace valve.
To replace the rotary valve:
1. Make sure the unit is unplugged from the wall outlet.
2. Remove the front cabinet and loosen the bib.
3. Unplug valve wire harness from the valve.
19
Voltage Reading
12 VDC
Gray 5 VDC
Brown 5 VDC
(intermittent)
2-3 VDC
LT-1928