30
■
If the self-diagnostics function fails to operate
<Checking the indoor and outdoor units>
■
Checking the indoor unit
■
Checking the outdoor unit
■
Checking the serial communications
●
Using the TEST/T-RUN terminals
Check the indoor unit.
Is the fuse blown?
Control
No.
Check items (unit operation)
Replace the controller.
Replace the circuit
board or the fuse.
• No indicators illuminate and the
indoor fan does not rotate.
• Check the power voltage.
T-RUN
: Test run (compressor and fan motor turn ON).
TEST/MV : Compresses time to 1/60th (accelerates
operation by 60 times faster than normal).
Set operation selector of indoor unit to
DEMO and start operation using the remote
controller.
●
If there are no problems with the above, then check the outdoor unit.
1
• The rated voltage must be present between inter-unit cables 1 and 2.
• Connect a 5 k
Ω
resistor between inter-unit cables 2 and 3. When the
voltage at both ends is measured, approximately 12–15 V DC must
be output and the multimeter pointer must bounce once every 8
seconds.
Or instead of measuring the voltage, you can insert an LED jig and
check that the LED flickers once every 8 seconds.
Control
No.
Check items (unit operation)
Short-circuit terminals 2 and 3 on
the indoor unit 3P terminal block.
Initial self-
diagnostics
Probable location of malfunction
Short-circuit terminals 2 and 3 on
the indoor unit 3P terminal block.
Apply the rated voltage between outdoor
unit terminals 1 and 2.
●
If there are no problems with the above, then check the indoor unit.
●
Turn the power OFF before performing short circuiting work.
●
During the self-diagnostics check, the check results are the first indication when the operation switch is set to OFF while the indicators
are blinking after power ON
→
DEMO (5 seconds)
→
ON.
●
So that the check can be made quickly, indicators blink at first communication after power ON.
●
Before performing the above checks, perform DEMO operation, and check that the rated voltage is output to terminals 1 and 2.
If it is not output, there is a failure related to the indoor unit power.
1
• The control panel LED (red) must illuminate.
Short-circuit the outdoor unit COM terminal
to the T-RUN terminal.
2
• The compressor, fan motor and 4-way valve must all turn ON.
Normal
Blown
TEST/T-RUN terminals
TEST/MV
T-RUN
COM
→
Control 1
No change
Indoor unit circuit board failure
Outdoor unit circuit board failure
Failure (open circuit, contact failure, etc.)
in the inter-unit cable
Outdoor unit circuit board failure
Change: (1) and (3) illuminate,
and (2) blinks.
(1) illuminates
Change: (1) and (3) illuminate,
and (3) blinks.
Change: (1) and (3) illuminate,
and (2) blinks.
Change: (1) illuminates
(1) and (3) illuminate,
and (2) flashes.
→
Control 2
