Mitsubishi Electric PU(H)Y-P250YGM-A, Service Handbook

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VII
Control ]
(3) Miscellaneous
When the errors other than described in the chart, the unit makes an error stop without performing emergency
operation. (Only the indoor fan operates, however; it stops when the fan is in trouble.)
When one of the two refrigerant circuits, the outdoor unit with the refrigerant circuit in error performs emergency
operation or makes an error stop, while the other outdoor unit keeps normal operation.
Emergency operation is intended only as a first aid until the unit is serviced. Have the unit serviced with-
out delay to restore a normal operation.
-5- Twenty-second restart-suspension mode
The unit will be in a twenty-second restart-suspension mode (same operation as Thermo OFF) in any of the fol-
lowing situations.
• When the demand for outdoor unit changes from Thermo ON to Thermo OFF.
• When operation mode changes from normal to emergency mode.
• When anti-freeze mode is completed.
* The outdoor unit has also a twenty-second restart-suspension mode, and it works separately from the
indoor unit.
* In heating mode, the mode changes to three-minute restart-prevention mode.
-6- Anti-Freeze Control (In cooling mode)
(1) Starting Conditions
This operation will start when all of the following conditions are met:
• Thermo ON status has been detected for 16 minutes.
• TH22 (liquid pipe temp. Thermistor) < 1 C has been detected for 20 minutes.
(2) Control Operation
The unit will be in the same condition as Thermo OFF condition for six minutes. When the following conditions
are met, the unit will be in a 20-second restart-suspension mode.
(3) Stopping Conditions
When either of the following conditions is met:
• TH22 10 C
• Six minutes have elapsed since the beginning of this operation.