Servo Controlled Oxygen Check; Leak Check; Pre-Use Checkout - GE Giraffe Service Manual

Chapter 2: Service Checkout

2.4 Servo Controlled Oxygen Check

2.4.1 Leak Check

This test checks for leaks between the O2 sensors and the Heat sink vent fitting.
1. Remove translation deck, tilt platform, upper pan, and fan.
2. Cover the heat sink vent near the fan shaft with adhesive tape. Make sure the tape will not interfere with
fan rotation. Reinstall the fan, upper pan, tilt platform, and translation deck.
nOTE: If the conical shaped rubber grommet was removed with the fan, when reinstalling fan be sure that
rubber grommet clicks into groove on fan shaft.
3. Power up the unit, hold down the 'Air curtain' button and press the 'Down' button to force the Giraffe into
low fan speed.
4. Set O2 set point to 21%; the display will show the actual concentration in the larger numerals next to the
set point. Open the doors until the actual concentration reaches 21% (ambient).
5. Run the Servo O2 calibration routine and wait for the calibration complete message. In approximately 20
seconds, the "Check O2 Supply" alarm should sound. If there is no alarm, the tubing between the sensor
housing and the heat sink vent fitting has a leak or is disconnected. Repair the leak and repeat steps 1
through 4 of this procedure.
6. After performing the test, power off the unit. Remove the translation deck, tilt platform, upper pan, and the
fan, and remove the adhesive tape. Be sure to remove any residue on the heat sink left by the tape.
7. Reassemble the system and run the calibration routine one final time.

2.4.2 Pre-use Checkout

This test checks for leaks between the chassis vent fitting and the O2 sensors.
1. Connect an acceptable hose from an oxygen supply to the oxygen inlet fitting on the unit. Supply pressure
should be between 310 kPa (45 PSI) and 586 kPa (85PSI).
2. Power up the unit.
3. Set the Air Control set point to the desired temperature.
4. Wait for the air temperature to stabilize. This could take about 45 minutes, depending on your
circumstances.
12
6600-0356-000 103
© 2001 by Datex-Ohmeda, Inc.. All rights reserved.