Fujitsu Comfort Series Service Manual page 23

Troubleshooting 2
HYDRAULIC UNIT Error Method:
Serial communication error
(Serial Forward Transfer Error)
Detective Actuators:
Hydraulic unit interface PCB
Forecast of Cause:
1. Connection failure
Check Point 1-1 : Reset the power and operate
Does Error indication show again?
YES YES
Check Point 2 : Check Connection
Check any loose or removed connection line of
hydraulic unit and Outdoor unit.
>> If there is an abnormal condition, correct it by
referring to Installation Manual or Data &
Technical Manual.
Check connection condition in control unit.
(If there is loose connector, open cable or mis-wiring)
OK
Check Point 3 : Check the voltage of power supply
Check the voltage of power supply
>> Check if AC198V (AC220V -10%) - 264V (AC240V +10%) appears
at Outdoor Unit Terminal L - N.
OK
Check Point 4 : Check Serial Signal (Forward Transfer Signal)
Check Serial Signal (Forward Transfer Signal)
>> Check if indicated value swings berween AC30v and AC130V at outdoor unit terminal 2 - 3.
>> If it is abnormal, replace interface PCB.
BLACK 1
2
WHITE
RED 3
L
BLACK
N
WHITE
Indicate or Display:
Hydraulic unit :
Green Red
1 1
n : n times blinking
Detective details:
When the outdoor unit cannot properly receive the serial signal from
hydraulic unit for 10 seconds or more.
2. External cause
NO
Check Point 1-2: Check external cause such as noise
AC
+
-
03-04
Outdoor unit :
Mode Error
2
: Light OFF
Check if the ground connection is proper.
Check if there is any equipment that causes harmonic wave
near the power cable (Neon light bulb or any electronic
equipment which causes harmonic wave).
AC
L1 L2 L3 L4 L5 L6
1 1
: Light ON n : n times blinking
AC