Troubleshooting
Si-95
104
Troubleshooting Inverter K Series
2.28
Malfunction of Transmission Between Indoor Units
Remote Controller
Display
UUU
U4444
Supposed Causes
■
Indoor to outdoor,outdoor to outdoor crossover wiring, disconnection or short circuit
■
Outdoor unit power supply is OFF
■
System address doesn’t match
■
Defect of indoor unit PC board
■
Defect of outdoor unit PC board
Troubleshooting
(VF054)
Is
indoor - outdoor and
outdoor - outdoor unit
transmission wiring
normal?
Supply 220~240 V.
Replace the fuse.
Fix the indoor/outdoor unit
transmission wiring.
Replace the outdoor unit PC
Board.
YES
NO
YES
Replace the indoor unit PC Board.
Push and hold the RESET button
on the outdoor unit PC Board for
5 seconds.
Fix the indoor/outdoor unit
transmission wiring.
YES
NO
NO
YES
Has
the indoor or
outdoor unit PC
board been replaced,
or has the indoor - outdoor or
outdoor - outdoor unit
transmission wiring
been modified?
All
indoor unit
remote controllers of the same
refrigerant system
display "U4."
NO
Outdoor unit PC
board microcomputer monitor
(HAP) blinks.
NO
NO
Operation
ready lamp (H2P) is
blinking.
Is indoor
- outdoor and outdoor -
outdoor unit transmission
wiring normal?
NO
The fuse on
the outdoor unit's PC board
is burnt.
Replace the transformer.
replacement
Replace outdoor unit PC board.
NO
The secondary
voltage of the transformer is
about 30 V.
NO
The voltage
between terminals R
and S of the outdoor unit PC
board is 220~240 V
(60Hz) or 220 V
(50 Hz).
∗
The unit will not operate for
up to 12 minutes.
Reset the power supply.
YES
YES
YES
YES
YES
Wait to lamp goes off.
SI-95.BOOK Page 104 Friday, March 31, 2000 10:59 AM