Operation Mode; Demand Control - Mitsubishi Electric PUHY-P250YNW-A Service Handbook

[5-2 Outdoor Unit Control ]
(2) Ending the emergency operation
1) End conditions
When one of the following conditions is met, emergency operation will end.
When an error is reset
*When resetting an error with the remote controller or the external input
When an error is detected that does not allow the unit to run the emergency operation.
2) Miscellaneous
When encountering problems other than the ones listed above, the system makes an error stop without performing emergen-
cy operation. (Only the indoor fan operates unless problems are found with the fan.)
When problems are found in only one of the two units of a 2-refrigerant circuit, only the unit with the problems will run an
emergency operation or stop its operation, and the other unit will keep running its operation.
Emergency operation is intended only as a first aid until the unit is serviced. Have the unit serviced without delay to restore a
normal operation.
2. Communication circuit failure or when some of the outdoor units are turned off
Emergency operation mode will not be performed if a fault occurs in internal/external communication or OC-OS communica-
tion.
5-2-14

Operation Mode

(1) Indoor unit operation mode
The operation mode can be selected from the following 3 modes using the remote controller.
1 Cooling mode
2 Fan mode
3 Stopping mode
(2) Outdoor unit operation mode
1 Cooling mode
2 Stopping mode
5-2-15

Demand Control

Cooling operation can be prohibited (Thermo-OFF) by an external input to the indoor units.
When DIP SW6-8 is set to ON, the 4-step DEMAND control is enabled.
Eight-step demand control is possible in the system with two outdoor units.
For details, refer to the following page(s). [2-4-7 Various Control Methods Using the Signal Input/Output Connector on Outdoor
Unit]
BS_05_C
All indoor units in operation are in cooling mode.
All indoor units are in fan mode or stopping mode.
15
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