Dehumidifier ML420-MLT1400
Symptom
Indicators
Possible cause
Corrective action
Safety device has tripped due to
one of the following:
Switch off the mains supply and allow the unit to cool down.
Fan motor fault
Investigate the cause of the fault, and rectify.
Drive motor fault
ML420: Reset QM16 - drive motor, reactivation fan and process fan.
ML690-MLT1400: Reset QM16 - reactivation fan.
Reset QM21 - drive motor or process fan. Reset QM18 for units with a
condenser.
Rotor stop warning
Investigate the cause of the “rotor stopped” warning and rectify the
fault.
Unit has
stopped.
No. 12, 2, 8
and/or 9 are
flashing.
Wiring fault
Switch on the mains supply at the mains supply switch, and start the
unit to reset the fault warning. If the fault reoccurs, contact Munters.
No. 11 and
12.
Units fitted with an air-cooled
condenser:
Safety devices have tripped due to
a condenser fan fault.
Switch off the mains supply and allow the unit to cool down.Investigate
the cause of the fault, and rectify.
Reset QM21.
Unit has
stopped.
Only No.
12.
Safety devices have tripped
due to a condenser heater fault
(reactivation air temperature)
Investigate the cause of the fault, and rectify.
Reset QM23.
Loss of
performance:
Temperature increase across the
reactivation battery is too low.
Check the function of the reactivation heater.
Reactivation and process airflows
do not correspond to the rated
airflows.
Check and adjust the reactivation airflow, see section
5.3, Airflow check and adjustment
Rotor drive failure.
Check rotor drive belt and drive motor.
Dehumidifier
appears to
be operating
correctly,
but is not
controlling
the humidity
Incorrect functioning of humidity
sensor, RH98 or VariDry
(
AUT
omatic mode).
Check the operation and connection of the humidity sensor, RH98 or
VariDry in accordance with the manufacturer’s recommendations.
Table 8.1 Fault tracing list
30
Fault tracing
190TGB-1035-H1604
