Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 66

5202 (F3): Low pressure sensor (63LS) trouble
Abnormal points and detection methods
• The detected pressure in the low pressure sensor is -33
psig (−2.3 kgf/cm
more during operation, the compressor stops operation
with error code 5202.
• For 3 minutes after compressor restarting, during de-
frosting operation, and for 3 minutes after returning from
defrosting operation, above mentioned symptoms are
not determined to be abnormal.
Diagnosis of failure
Check the wiring and connector connection.
Is there any abnormality such as
disconnection, looseness or break-
age?
Check the internal pressure of the refrigerant
circuit.
Is the detected internal pressure
normal?
Check the detected pressure in 63LS, then
compare it with the internal pressure.
Is the detected pressure normal?
OCH800A_66
2 ) or less, or 329 psig (23.1 kgf/cm
Yes
No
No
Yes
The detected pressure in 63LS can be displayed by an
operation of SW1 on the outdoor multi controller circuit board.
ON
OFF
No
Yes
Causes and checkpoints
• Defective low pressure sensor
2 ) or • Decrease of internal pressure caused by gas leakage
• Disconnection or contact failure of connector
• Malfunction of input circuit on outdoor multi controller
circuit board
Connect the wiring/connector properly.
Replace it in the case of breakage.
Check the refrigerant circuit, and refill refrigerant
after repairing the leakage.
SW1 Setting Display on LED1,2
Unit
-99.9–999.9 psig
1 2 3 4 5 6 7 8
Replace the 63LS.
Replace the outdoor multi controller circuit
board.
The black square (■) indicates a switch position.