Mitsubishi Electric PUHZ-SHW230YKA2 Service Manual page 18

Check Code
Abnormal point and detection method
Miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
1. Outdoor controller circuit board can
automatically check the number of con-
nected Interface unit/Flow temp. control-
ler. Abnormal if the number cannot be
checked automatically due to miswiring
of Interface unit/Flow temp. controller-
outdoor unit connecting wire, etc. after
power is turned on for 4 minutes.
2. Abnormal if outdoor controller circuit
board recognizes excessive number of
EA
Interface unit/Flow temp. controller.
Miswiring of Interface unit/Flow temp.
controller-outdoor unit connecting wire
(reverse wiring or disconnection)
Outdoor controller circuit board can auto-
matically set the unit number of Interface
unit/Flow temp. controller.
Abnormal if the Interface unit/Flow temp.
controller number cannot be set within 4
minutes after power on because of miswir-
ing (reverse wiring or disconnection) of
Interface unit/Flow temp. controller-outdoor
unit connecting wire.
Eb
Startup time over
The unit cannot finish start up process
within 4 minutes after power on.
EC
OCH594B
Case
Contact failure or miswiring of
Interface unit/Flow temp. controller-
outdoor unit connecting wire
Diameter or length of Interface
unit/Flow temp. controller-out-
door unit connecting wire is out
of specified capacity.
Excessive number of Interface
unit/Flow temp. controller is
connected to 1 outdoor unit.
(2 units or more)
Defective transmitting receiv-
ing circuit of outdoor controller
circuit board
Defective transmitting receiving
circuit of Interface/Flow temp.
controller board
Noise has entered into power
supply or Interface/Flow temp.
controller-outdoor unit connect-
ing wire.
Contact failure or miswiring of
Interface unit/Flow temp. control-
ler-outdoor unit connecting wire
Diameter or length of Interface
unit/Flow temp. controller-out-
door unit connecting wire is out
of specified capacity.
Defective transmitting receiving circuit
of outdoor controller circuit board
Defective transmitting receiving
circuit of Interface/Flow temp.
controller board
Noise has entered into power supply
or Interface unit/Flow temp. control-
ler-outdoor unit connecting wire.
Contact failure of Interface unit
/Flow temp. controller-outdoor
unit connecting wire
Diameter or length of Interface
unit/Flow temp. controller-
outdoor unit connecting wire is
out of specified capacity.
Noise has entered into power sup-
ply or Interface unit/Flow temp.
controller-outdoor unit connecting
wire.
18
Judgment and action
Check disconnection or looseness or polarity
of Interface unit/Flow temp. controller-outdoor
unit connecting wire of Interface unit/Flow
temp. controller and outdoor units.
Check diameter and length of Interface unit/
Flow temp. controller-outdoor unit connecting
wire.
Total wiring length: 80 m
(Including wiring connecting each Interface
unit/Flow temp. controller unit and between
Interface unit/Flow temp. controller and out-
door unit)
Also check if the connection order of flat
cable is S1, S2, S3.
Check the number of Interface unit/Flow
temp. controller that is connected to 1 out-
door unit. (If EA is detected.)
– Turn the power off once, and on again to
check.
Replace outdoor controller circuit board
or Interface/Flow temp. controller board if
abnormality occurs again.
Check transmission path, and remove the
cause.
Note: The descriptions above,
Eb and EC.
– , are for EA,