Humidity Failure Alarm - GE Giraffe OmniBed Carestation CS1 Service Manual

Chapter 6: Alarms and System Failure Codes
Alarms

6.1.16 Humidity Failure Alarm

Note: The Humidity Failure alarm can be caused by non-humidifier issues.
Cause or Circumstances
The Motor Drive Failure alarm is
on.
The Elevating base does not
function. If the elevating base
does not function, then safety
relay 2 is not being energized.
Elevating base functions.
Humidifier heater measures
OK.
No mains voltage at input to
humidifier isolation
transformer (J55, 1-2).
The Humidity Sensor Failure
alarm indicates that the
humidity sensor failed and the
humidifier is not operating.
6-8
Failure
If this alarm activates, it opens
safety relay 2 and disables the
humidifier.
Defective 50 pin ribbon cable
between the relay and control
board.
Humidifier safety thermostat is
open.
Defective humidifier heater or
humidifier safety thermostat.
Relay boards rev 10 or higher.
Relay boards rev 9 or lower.
Humidifier Interface Board is
mounted on relay board.
Defective fuse. Relay boards
rev 10 or higher.
Defective fuse. Relay boards
rev 9 or lower. Humidifier
Interface Board is mounted on
relay board.
Defective relay board.
Humidity sensor failed.
Action
Refer to section 6.1.18 for
troubleshooting.
Check for continuity on pin 34
(safety relay 2 control signal). If
defective, replace the cable. If good,
replace the relay board.
Wait for the heater to cool. Cycle
power to see if alarm resets.
Check safety thermostat and
humidifier heater resistance.
In service Mode, verify mains
voltage is present at the input to
the humidifier isolation
transformer. (J55 1-2)
In service Mode, verify mains
voltage is present at the input to
the humidifier isolation
transformer. (J56 1-2) J56 is on
Humidifier Interface Board
mounted on relay board.
Check fuses F3 and F4 on the relay
board. If OK, continue.
Check fuses on humidifier interface
board.
Replace the relay board.
Replace the sensor.
Service Manual