Service manual

Service Manual 55
675-120 Revision D May 2005
Error
Code
Fault Condition Consequence
Software
Response
Corrective
Action
E20 Charged battery voltage
too low (<11 V) when
under test load.
No backup – battery
capacity low.
Battery fault icon
flashes and ‘Error
number’ alarm
prompt.
Replace
battery or
charger.
E21 External supply voltage too
low (<14 V) to charge
battery (battery flat).
No backup – battery will
not charge.
Battery low alarm
continues even
when external
power applied.
‘Error number’
alarm prompt.
Replace the
PSU module.
E22 Analog supply rails out of
limits.
Unusable - unreliable
sensor readings.
User lockout
‘Error number’
prompt.
Replace the
main control
PCB and
re-calibrate O
2
and pressure
sensors.
E23 Valve driver supply rails
out of limits.
Unusable - unreliable
valve operations.
User lockout
‘Error number’
prompt.
Replace the
main control
PCB and re-
calibrate O
2
and pressure
sensors.
E24 Hardware safe-start
watchdog disabled.
Unusable – valve
disabled.
User lockout
‘Error number’
prompt.
Power cycle
unit. If fault
still occurs,
replace the
main control
PCB and
re-calibrate O
2
and pressure
sensors.
E30 Pressure sensor fault
(ADC hits rail).
Unusable – pressure
sensor readings invalid.
User lockout
‘Error number’
prompt.
Replace the
pneumatics
PCB and re-
calibrate O
2
and pressure
sensors.
E31 Zero valve not connected
(via sense).
Unusable – pressure
sensor readings
unreliable.
User lockout
‘Error number’
prompt.
Replace the
pneumatics
PCB and re-
calibrate O
2
and pressure
sensors.