105 of 222 pages
Operating and service manual
401
Mevap 2 overheat
Warning
Description
Evaporator Motor 2 Overheat
Cause
Indication of an overheated motor or a loose thermistor cable connection
Trouble
shooting
Possible causes:
•
Evaporator motor 1 defect.
•
Defect resistances on the interface/terminal block PCB.
•
Cable for measuring evaporator motor 1 overheat defect.
•
Controller PCB defective.
Accompanied alarms:
•
N/A.
Trouble shooting:
1) Turn off unit! Open inspection hatch and see if the evaporator fan can
turn freely. If it cannot turn, remove ice or replace the motor. If the
motor is hot, it may be overloaded and jammed or defect.
2) If the cable for Mevap2OH by inspection is defect, replace cable.
3) Disconnect the cable for Mevap2OH from the connector PCB according to
the wiring schematics inside the control cabinet.
4) Measure the resistance in the cable. If the resistance is more than 1 MΩ,
the cable or the motor is defect and should be replaced. If the resistance
is less than (<) 5 kΩ, the cable and motor should be ok.
5) Check resistances on the interface/terminal block PCB above X33 and
X34. They must be 220 kΩ
6) Turn unit on again. Measure the voltage over the connector for
Mevap2OH. It should be between 4.80V DC and 5.05V DC.
a) If the voltage is inside the above range, connect sensor again. Measure
the voltage over the sensor and check the voltage. If the voltage is less
than (<) 2.5V DC, the measurement is ok. If the alarm after 30 sec. is
still active on the display, the controller PCB is defect - replace controller
door.
b) If the voltage is outside the range, controller PCB is defect or another
error might affect the voltage. Check other alarms before replacing
controller door.
Criteria
Value above high alarm limit 10K Ohm.
Controller
action
Both evaporator fan motors are stopped
Log
X
Alarm
X
Alarm light
Off
Consequence
Air circulation in container stops causing unit to stop
Elimination
When overheating ceases, alarm will be marked as inactive in alarm list and may then be
deleted. Control is again released but fan motors will only be allowed to operate at low
speed for the first 5 min. If error does not reoccur, problem will be considered solved and
evaporator fan high speed is again released.
Log data
Parm 1
Parm 2
Parm 3
Parm 4
Parm 5
Active/Inactive
High limit
Current