Sensor Calibration (Nu-4950) - NuAire 7 Series Maintenance Manual

OM0123
Rev 15
- RH over setpoint
- RH time out error
- Humdity Control Alarm
Calibration or other over injection issue: The
duration of the humidity injection was too
long or there were too many injections of
humidity causing this alarm. The evaporator
tank heater is shut off then, after drying out
and cool down period a continuous humidity
injection is resumed to maintain a near 90%
humidified condition in the chamber until the
alarm is addressed. When the tank heater is
turned off the resevoir light on the control
label will light up. It will stay lit until the tank
is back up to operational temperature of 60
to 70 deg. C.
Failed sensor signal issue: The alarm sounds
immediately in this condition. When the
alarm is cleared it will alarm again
immediately in this condition.
- O under setpoint
2
- O time out error
2
- N tank switch occurrence
2
- O sensor fuel cell low output signal
2
RH Percent
1. Check for other sources of humidity in the
chamber, i.e. excessive condensation and remove.
2. Check inject valve for leaking.
3. Check the shuttle valve and replace if faulty.
4. Perform RH sensor calibration.
1. Check RH reservoir for water level and water
pan if used for low O
2. Check the shuttle valve and replace if faulty.
3. Perform sensor calibration.
1. Calibrate sensor (see section 9.4)
2. Check RH tank heater for function
3. Check RH reservoir float switch for function
4. If condensation is not a problem the acceptable
length & number of injections can be increased
by accessing the "Opt" (Option) menu.
5. If nuisance alarms persist, this position of the
HC alarm can be turned off in the "OPt" menu
1. Check for loose or broken connection
2. RH sensor is wet, let dry out and check for
function.
3. RH sensor is faulty and needs replacement.
O2 Percent
1. Perform O
2. Replace sensor
3. Check inject valve for leaking
1. Perform O
2. Check N
1. Check N
1. Replace O
2. Calibrate O
until new sensor is replaced
3. Calibrate O
installed
Page 54 of 68
setpoints.
2
sensor calibration
2
sensor calibration
2
gas supply tanks
2
gas supply tanks
2
sensor
2
sensor to adjust output reading
2
system when new sensor is
2