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Subject to change without notice | 83019600bUK – Translation of the original operating manual | ait-deutschland GmbH
10 Alarm list
Alarm Alarm text on the
display
Description
May be due to
162
High condenser out Too high temperature out from
the condenser. Self-resetting.
• Low flow during heating operation
• Too high set temperatures
163
High condenser in
Too high temperature into the
condenser. Self-resetting.
• Temperature generated by another heat
source
183
Defrosting in
progress
Not an alarm, but an operating
status.
• Set when the heat pump runs the defrosting
procedure
220
HP alarm
The high pressure switch (63H1)
deployed 5 times within 60 min
-
utes or for 60 minutes
continuously.
• Insufficient air circulation or blocked heat
exchanger
• Open circuit or short circuit on input for
high pressure switch (63H1)
• Defective high pressure switch
• Expansion valve not correctly connected
• Service valve closed
• Defective control board in L…Split
• Low or no flow during heating operation
• Defective circulation pump
• Defective fuse, F(4A)
221
LP alarm
Too low a value on the low pres
-
sure sensor (LPT) 3 times within
60 minutes.
• Open circuit or short circuit on input for
low pressure sensor
• Defective low pressure sensor (LPT)
• Defective control board in L…Split
• Open circuit or short circuit on input for
suction gas sensor (Tho-S)
• Defective suction gas sensor (Tho-S)
223
OU Com. error
Communication between the
control board and the communi
-
cation board is interrupted.
There must be 22 volt direct cur
-
rent (DC) at the switch CNW2
on the control board (PWB1).
• Any circuit breakers for L…Split off
• Incorrect cable routing
224
Fan alarm
Deviations in the fan speed in
L…Split.
• The fan cannot rotate freely
• Defective control board in L…Split
• Defective fan motor
• Control board in L…Split dirty
• Fuse (F2) blown
