Mitsubishi Electric PAC-MK51BC Manuel D'installation page 14

9. Test run
• Refer to the "Test run" section of the installation manual of the indoor units and outdoor unit.
• When the branch box and outdoor power source are separate, turn on the power of the branch box fi rst, and then turn on the outdoor unit power.
• After power is supplied or after an operation stop for a while, a small clicking noise may be heard from the inside of the branch box. The electronic expan-
sion valve is opening and closing. The unit is not faulty.
• Be sure to perform the test run in cooling mode for each indoor unit. Make sure each indoor unit operates properly following the installation manual attached to the unit.
• If you perform the test run for all indoor units at once, you cannot detect any erroneous connection, if any, of the refrigerant pipes and the indoor/outdoor unit connecting
wires.
• To check for improper wiring, perform the test run for each indoor unit individually.
Caution:
• Use the remote controller to operate the indoor unit.
• The following symptoms are not malfunctions.
Symptom
Indoor unit does not operate even if set to
cooling (heating) operation
Indoor unit fan stops during heating operation
ddaff
* See the operation manual of indoor units for details.
** This mode is activated for approximately 1 minute to help avoid an insuffi cient supply of refrigerant during heating operation when refrigerant is stored in an indoor unit
that has been turned off or thermo-off.
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The cooling (heating) operation cannot be operated when the heating (cooling)
operation of another indoor unit is operating.
The fan stops during defrosting operation.
Fan stops when the refrigerant collecting mode ** is activated.
Cause Indoor unit LED display *
Stand by (For Multi System)
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Stand by (For Multi System)