24
Faults, Cause and Remedy
253 Ex concentration has drifted
into the negative range
Carry out the fresh air calibra-
tion, page 36.
254 The temperature is too high Operate the device within the
allowed temperature range.
255 The temperature is too low Operate the device within the
allowed temperature range.
256 The calibration interval for
DrägerSensor CatEx 125 PR
has elapsed
Carry out the span calibration
for DrägerSensor CatEx
125 PR, page 40.
257 Alarm setpoint A2 setting is
greater than 60 %LEL
Set alarm setpoint to less than
60 % LEL.
351 DrägerSensor XXS O
2
in the
warm-up phase
Wait until warm-up time is
complete.
352 DrägerSensor XXS O
2
in the
warm-up phase
Wait until warm-up time is
complete.
353 O
2
concentration drifted into
the negative range
Fresh air calibration required,
page 36.
354 The temperature is too high Operate the device within the
allowed temperature range.
355 The temperature is too low Operate the device within the
allowed temperature range.
356 The calibration interval for
DrägerSensor XXS O
2
has
elapsed
Carry out the span calibration
for DrägerSensor XXS O
2
,
page 40.
451 DrägerSensor XXS H
2
S in the
warm-up phase
Wait until warm-up time is
complete.
452 DrägerSensor XXS H
2
S in the
warm-up phase
Wait until warm-up time is
complete.
453 H
2
S concentration has drifted
into the negative range
Carry out the fresh air calibra-
tion, page 36.
454 The temperature is too high Operate the device within the
allowed temperature range.
455 The temperature is too low Operate the device within the
allowed temperature range.
456 The calibration interval for
DrägerSensor XXS H
2
S has
elapsed
Carry out the span calibration
for DrägerSensor XXS H
2
S,
page 40.
551 DrägerSensor XXS CO in the
warm-up phase
Wait until warm-up time is
complete.
Special symbol » « and
displayed numerical code:
Cause Remedy