JULABO EH-39 Open Bath Circulator - Manual (Page 26)

Troubleshooting guide / Error messages
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7. Troubleshooting guide / Error messages
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Whenever the microprocessor electronics registers a failure, a complete
shutdown of the heater and circulating pump is performed. The alarm
light " " illuminates and a continuous signal tone sounds.
The LED temperature display indicates the cause for the alarm in form of
a code.
Press the key to quit the audible signal.
 The circulator is operated without bath fluid, or the liquid level is
insufficient.
Replenish the bath tank with the bath fluid.
 Tube breakage has occured (insufficient filling level due to excessive
bath fluid pumped out). Replace the tubing and replenish the bath
tank with the bath fluid.
 During the self-test after switch-on a short-circuit is registered
between pin 2 and pin 4 of the control cable or the control cable is
interrupted during operation.
Reconnect the cable or eliminate the short-circuit.
 Cable of the working temperature sensor interrupted or short-
circuited.
 Defect of the working or excess temperature sensor.
Working temperature and excess temperature sensors report a
temperature difference of more than 35 K.
 Error in A/D converter
 The excess temperature value lies below the working temperature
setpoint.
Set the excess temperature to a higher value.
 Cable of the excess temperature sensor interrupted or short-circuited.
After eliminating the malfunction, press the mains power switch off and
on again to cancel the alarm state.
If the unit cannot be returned to operation, contact an authorized
JULABO service station.