27
OCH721A
Check code Abnormal points and detection method
Cause
judgment and action
F5
(5201)
63H connector open
Abnormal if 63H connector circuit is open for
3 minutes continuously after power supply.
63H: High pressure switch
1
Disconnection or contact failure
of 63H connector on outdoor
controller circuit board
2
Disconnection or contact failure
of 63H
3
63H is working due to defective
parts.
4
Defective outdoor controller
circuit board
1
Check connection of 63H connector on
outdoor controller circuit board.
Refer to "10-9. TEST POINT DIAGRAM".
2
Check the 63H side of connecting wire.
3
Check continuity by tester.
Replace the parts if the parts are defective.
4
Replace outdoor controller circuit board.
EA
(6844)
Miswiring of indoor/outdoor unit
connecting wire
Outdoor controller circuit board can
automatically check the number of
connected indoor units. Abnormal if the
number cannot be checked automatically
due to miswiring of indoor/outdoor unit
connecting wire, etc. after power is turned
on for 4 minutes.
Abnormal if outdoor controller circuit board
recognizes excessive number of indoor
units.
1
Contact failure or miswiring of
indoor/outdoor unit connecting wire
2
Diameter or length of indoor/
outdoor unit connecting wire is
out of specified capacity.
3
Excessive number of indoor
units are connected to 1 indoor
unit. (4 units or more)
4
Defective transmitting receiving
circuit of outdoor controller
circuit board
5
Defective transmitting receiving
circuit of indoor controller board
6
Defective indoor power board
7
2 or more outdoor units have
refrigerant address “0” .
(In the case of group control)
8
Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
1
Check disconnection or looseness or polarity
of indoor/outdoor unit connecting wire of
indoor and outdoor units.
2
Check diameter and length of indoor/outdoor
unit connecting wire.
Total wiring length: 262 ft [80 m]
(including wiring connecting each indoor unit
and between indoor and outdoor unit)
Also check if the connection order of flat cable
is S1, S2, S3.
3
Check the number of indoor units that are
connected to one outdoor unit. (If EA is
detected)
4
–
6
Turn the power off once, and on again to
check.
Replace outdoor controller circuit board,
indoor controller board or indoor power
board if abnormality occurs again.
7
Check if refrigerant addresses (SW1-3 to
SW1-6 on outdoor controller circuit board)
are overlapping in the case of group control
system.
8
Check transmission path, and remove the
cause.
Note: The descriptions above,
1
–
8
, are for EA,
Eb and EC.
Eb
(6845)
Miswiring of indoor/outdoor unit
connecting wire (reversed wiring or
disconnection)
Outdoor controller circuit board can
automatically set the unit number of indoor
units.
Abnormal if the indoor unit number can-
not be set within 4 minutes after power on
because of miswiring (reversed wiring or
disconnection) of indoor/outdoor unit con-
necting wire.
1
Contact failure or miswiring of
indoor/outdoor unit connecting wire
2
Diameter or length of indoor/
outdoor unit connecting wire is
out of specified capacity.
4
Defective transmitting receiving cir-
cuit of outdoor controller circuit board
5
Defective transmitting receiving
circuit of indoor controller board
6
Defective indoor power board
7
2 or more outdoor units have
refrigerant address “0” .
(In the case of group control)
8
Noise has entered into power
supply or indoor/outdoor unit
connecting wire.
EC
(6846)
Startup time over
The unit cannot finish Startup process with-
in 4 minutes after power on.
1
Contact failure of indoor/
outdoor unit connecting wire
2
Diameter or length of indoor/
outdoor unit connecting wire is
out of specified capacity.
7
2 or more outdoor units have
refrigerant address “0” .
(In the case of group control)
8
Noise has entered into power
supply or indoor/outdoor unit
connecting wire.