01.07.2022
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AHP60-14/18 -
Installation, Use and Maintenance
Code Description
Cause
Solution
E651
Failure of
the external
air sensor
The EXT1 sensor is defective
• Check that the EXT1 sensor is attached correctly to
the terminals CN3 1-2
E691
Low pressure
sensor
failure
The LP1 low pressure sensor
is defective
• Check that the LP1 sensor is attached correctly to
the terminals CN1 1-2
E701
High
pressure
sensor
failure
The HP1 high pressure sensor
is defective
• Check that the HP1 sensor is attached correctly to
the terminals CN1 3-4
E801
(*)
Inverter
board
communication
error
• The communication cable
between the inverter board
and the fan boards is not
connected or is defective.
• The opto-coupler OPT1 is
defective or not powered
• Check the fuse on the fan
board
• Check the communication cable between the
command terminals CN15 2-3, opto-coupler
OPT1 (see electrical diagram), fan board FD1 and
compressor board INV1:
Inverter
compressor
Fan board
Coupler
isolator
switch
V415
control
unit
