GE Giraffe OmniBed Carestation CS1, Service Manual

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Chapter 3: Calibration and Maintenance
Special Tools
Service Manual 3-3
3.2 Special Tools
The following tools (or their functional equivalents) are required to complete the recommended service
procedures:
• Digital Multimeter, 4-1/2 digit
• Leakage Current Tester
• PLCC Extractor for removing socketed chips
• Static Control Work Station (recommended)
• Light gray touch-up paint (Munsell .16GY8.56-0.44 chroma), 18 ml .................................... 6600-0714-200
• Servo Humidity Calibration Kit............................................................................................................... 6600-0048-850
• 5 kilogram (5000 gram) Certified Test Weight ................................................................................ 6600-0209-800
3.3 System Calibration
Note: If only performing line voltage calibration, follow instructions in section 3.4 .
Important: Be sure to perform System Calibration after replacing a control board.
1. Turn power off.
2. Remove electrical enclosure back panel.
3. Unplug the temperature sensors from J1, J4 and J2 on the control board.
4. Move jumper JP1 to the CAL MODE position on the control board (refer to “Figure 3-1 Control Board Test
Points” ). Be sure to orient the jumper correctly so pins 5-6 and 7-8 are shorted.
5. Turn power on.
After running the power-up testing a progress bar is displayed at the top of the screen.
Upon completion, the calibrate mode screen appears.
6. Using a 4 ½ digit DVM (capable of measuring to 0.1 millivolt) measure VREF at TP1, pins 1 and 6 (pin 6 is
ground) on the control board. Measure to the nearest 0.1 millivolt. (Typical voltage reading will be
1.2350.)
7. Once "Enter reference voltages" is displayed, enter the VREF using the keypad.
8. Touch Enter.
9. Measure the Mains Voltage at the AC connectors at the bottom of the electronics enclosure cover.
10. Once "Enter mains voltages" is displayed enter the voltage using the keypad.
11. Touch Enter.
12. When complete, Calibration DONE appears across the top of screen. Do not shut off the device until the
DONE message is displayed or the new calibration values will not be stored.
13. If the message “Mains voltage calibration failed. Please enter the mains voltage again” appears this
indicates the entered line voltage is 20% different than the measured value (not the nominal value).
14. Power down the device and move the calibrate jumper to the NORMAL MODE position. Be sure to orient
the jumper correctly so pins 1-2 and 3-4 are shorted.
15. System and line voltage calibration are complete.
16. Proceed to humidifier calibration.