Sanyo KMS2472, KMS1872 service manual Checking the Indoor and Outdoor Units

8-3. Checking the Indoor and Outdoor Units

(1) Checking the indoor unit

No.

Control

Check items (unit operation)

1

Use the remote controller to operate the

• The rated voltage must be present between inter-unit wirings 1 and 2.

unit in "TEST run" mode. To determine

• Connect a 5 k ohm resistor between inter-unit wirings 2 and 3. When the

whether the mode is currently in

voltage at both ends is measured, approximately 12 to 15V DC must

"TEST run" mode, check the 4 indicator

be output and the multimeter pointer must bounce once every 8

lamps on the unit. If all 4 are blinking,

seconds.

the current mode is "TEST run."

Or instead of measuring the voltage, you can insert an LED jig and

check that the LED flickers once every 8 seconds.

If there are no problems with the above, then check the outdoor unit.

For the "Test run" procedure, refer to "4. How to Test Run the Air Conditioner" on Appendix B.

(2) Checking the outdoor unit

No.

Control

Check items (unit operation)

1

Apply the rated voltage between outdoor

• The control panel LED (red) must illuminate.

unit terminals L1 and L2.

2

Short-circuit the outdoor unit COM terminal

• The compressor and fan motor must all turn on.

to the T-RUN terminal.

If there are no problems with the above, then check the indoor unit.

Using the TEST/T-RUN terminals

TEST/T-RUN terminals

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).

(TEST)/MV

T-RUN

COM

(3) Checking the serial communications

.... OFF

.... Blinking

.... Illuminated

Control 1

Control 2

Initial self-diagnostics

Short-circuit terminals 2 and 3 on

Short-circuit terminals 2 and 3 on

the indoor unit terminal plate.

the outdoor unit terminal plate.

Probable location of malfunction

Quiet

Timer

Operation

Quiet

Timer

Operation

Quiet

Timer

Operation

( 3 )

( 2 )

( 1 )

( 3 )

( 2 )

( 1 )

( 3 )

( 2 )

( 1 )

Indoor unit circuit board failure

Outdoor unit circuit board failure

Failure (open circuit, contact failure, etc.)

in the inter-unit wirings

Outdoor unit circuit board failure

Turn the power OFF before performing short circuiting procedures.

Refer to the previous pages when performing system self-diagnostics.

So that the check can be made quickly, indicators blink at first communication after power ON.

Before performing the above checks, perform “TEST run” operation, and check that the rated voltage is output to terminals L1 and L2 on the outdoor unit. If it is not output, there is a failure related to the indoor unit power.

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