Troubleshooting - Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual

8

TROUBLESHOOTING

8-1. Checkpoints for test run
8-1-1. Procedures before test run
1. Before a test run, make sure that the following work is completed.
• Installation related:
Make sure that the panel of cassette type is installed and electrical wiring is done.
Otherwise electrical functions like auto vane will not operate normally.
• Piping related:
Perform leakage test of refrigerant and drain piping. Make sure that all joints are perfectly insulated.
Check stop valves on both liquid and gas sides are fully open.
• Electrical wiring related:
Check ground wire, transmission cable, remote controller cable, and power supply cable for secure connection.
Make sure that all switch settings of address or adjustments for special specification systems are correctly made.
2. Safety check:
• With the insulation tester of 500 V, inspect the insulation resistance.
• Do not touch the transmission cable and remote controller cable with the tester.
• The resistance should be over 1.0 MΩ. Do not proceed inspection if the resistance is less than 1.0 MΩ.
• Inspect between the outdoor unit power supply terminal block and ground first, metallic parts like refrigerant pipes
or the electrical box next, then inspect all electrical wiring of outdoor unit, indoor unit, and all linked equipment.
3. Before operation:
• For compressor protection, turn on the breaker for the outdoor unit and wait at least 12 hours before a test run.
- The unit might NOT run, in order to protect the compressor, in the case of low outside air temperature.*
• Register control systems into remote controller(s). Never touch the on/off switch of the remote controller(s). Refer to
˝Special function operation setting (for M-NET Remote Controller)˝ as for settings.
In MA remote controller(s), this registration is unnecessary.
4. More than 12 hours later after turning on the power to the outdoor unit, turn on all the power switches for the test run.
Perform test run and make test run reports.
Caution:
* The compressor may not operate immediately after recovery from power failure. Refer to "SW6-3" in 8-5. "Internal switch function table" for how to deal
with it.
8-1-2. Test run for M-NET remote controller
Refer to "Test run" for operation procedure.
8-1-3. Countermeasures for error during test run
If a problem occurs during test run, a code number will appear on the remote controller (or LED on the outdoor unit), and
the air conditioning system will automatically cease operating.
Determine the nature of the abnormality and apply corrective measures.
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Error Error
code code
(2 digits) (4 digits)
Ed 0403
U2 1102
UE 1302
U7 1500
U2 1501
P6 1503
EF 1508
L6 2135
PA 2500
P5 2502
P4 2503
- 3121
UF 4100
Pb 4114
UP 4210
U9 4220
U5 4230
U6 4250
U8 4400
OCH800A_33
Trouble
Serial communication error/Model selection SW error
Compressor temperature trouble
High pressure trouble or compressor protector trouble
Superheat due to low discharge temperature trouble
Refrigerant shortage trouble
Closed valve in cooling mode
Freeze protection of plate heat exchanger
Freeze protection of branch box or indoor unit
4-way valve trouble in heating mode
Circulation water freeze protection
Water leakage
Drain overflow protection
Drain sensor abnormality
Out-of-range outside air temperature
Compressor current interruption (locked compressor)
Fan trouble (Indoor unit)
Compressor overcurrent interruption/Failure in 12 VDC
power supply circuit on power circuit board
Voltage shortage/overvoltage/PAM error/L1 open
phase/primary current sensor error/power synchroni-
zation signal error
Heat sink temperature trouble
Power module trouble
Fan trouble (Outdoor unit)
Detected Unit
Remote
Indoor Outdoor
Controller
Outdoor unit outdoor multi controller circuit
О board – Power circuit board communication
trouble, Incorrect setting of model selection
О Check delay code 1202
О Check delay code 1402
О Check delay code 1600
О Check delay code 1601
О Check delay code 1501
О
О
О Check delay code 1608
О
О
О
О
О
О Check delay code 4350
О
О
Check delay code 4320
О
О Check delay code 4330
О Check delay code 4350
О Check delay code 4500
Remarks