JULABO Magnum 91 Temperature System - Manual (Page 58)

Troubleshooting guide / Error messages
58
WARNING
CODE 21 Compressor stage 1 does not work.
 After a short cooling interval, the compressor motor will be automatically
reconnected and the message "CODE 21" no longer appears.
In order to guard against a destruction of particular components of the refrigerant
cycles, different control sensors were installed. The following messages explain the
particular incidences and give indication for further action.
WARNING
CODE 27 The compressors of both stages were switched off.
 The high pressure controller in stage 1 measures an excessive pressure. As soon
as the pressure in stage 2 reaches the lower switching point, the compressors are
switched on again one after the other.
 The motor winding protection in stage 1 measures an excessive temperature.
As soon as the temperature in stage 1 reaches the lower switching point, the
compressors are switched on again one after the other.
Check the cooling water supply line.
Wait until the pressure compensation in stage 1 is finished and switch on the unit
again after waiting for about 25 minutes.
WARNING
CODE 28 The compressor of both stages were switched off.
 The exit temperature of stage 1 is too high. As soon as the temperature reaches
the lower switching point, and – as second condition – the pressure proportions
allow it, the compressors are switched on again delayed.
ALARM
CODE 29 The exit temperature of stage 1 is too high.
 For this reason the compressors of both stages have already been switched off 4
times. (see warning CODE 28).
After a cool-down phase the alarm status can be cancelled by switching off and
on again at the mains switch, and the unit is ready to operate again.
In order to avoid the destruction of the compressor, the refrigerant cycle of 1st
stage should be checked by a specialist first.
ALARM
CODE 30 The temperature sensor for the exit temperature of stage 1 is bypassed, or there is a
line interruption.
 Have the repair done by a specialist. .
WARNING
CODE 40 Low liquid level warning
WARNING
CODE 41 High liquid level warning
 The fluid level in the reservoir is only a few millimeters below the overflow port
(12).
WARNING
CODE 42 Already for a period of 5 minutes the pressure in stage 2 (high pressure side) is too
high.
 The cooling system works at its limit. If the pressure falls below a factory-made
value for at least 100 seconds, the warning expires again.