Emergency Operation; Trouble To Which Emergency Operation Can Be Set; Check Items And Notices As The Emergency Operation; How To Operate The Emergency Operation - Mitsubishi Electric Mr.SLIM PU-P71VHA Service Manual

11-9. EMERGENCY OPERATION

1. When the outdoor unit becomes under mentioned inspection display. Also when the wired remote controller or microproces-
sor in the indoor unit is broken. If there is not any wrong section, short-circuited connector (CN31) in the outdoor controller
board is possible to emergency operation.

Trouble to which emergency operation can be set

Display
U4
Piping thermistor (TH3) or condenser thermistor (TH6) open/short
E8 Transmission between indoor and outdoor unit
E9 Transmission between indoor and outdoor unit
E0~E7 Transmission trouble except for outdoor unit

2. Check items and notices as the emergency operation

(1) Be sure that there is no trouble in the outdoor unit any more besides above mentioned.
(When there is trouble besides above mentioned, emergency operation is not available.)
(2) When the emergency operation, their switch (SWE) setting in the indoor controller board is necessary.
(3) Emergency operation will be serial operation by the power supply ON/OFF.
ON/OFF or temperature, etc. adjustment is not operated by the remote controller.
(4) Do not operate for a long time as cold air is blown from the indoor unit, when the outdoor unit starts defrosting operation
during heating emergency operation.
(5) Cool emergency operation must be within 10 hours at most. It may cause heat exchanger frosting in the indoor unit.
(6) After completing the emergency operation, return the switch setting, etc. in former state.

3. How to operate the emergency operation

(1) Turn off the main power supply.
(2) Turn on the emergency switch (SWE) in the indoor controller board.
(3) Short-circuit the CN31 (emergency operation connector) in the outdoor controller board.
(4) Set the operation mode (COOL or HEAT) with the SW4-2 in the outdoor controller board.
(SW4-1 cannot be used.)
(5) Turn on the main power supply.
(6) The emergency operation starts and be sure of blinking the operation mode display.
4. Emergency operation details
(1) Operate with the operation mode which has set (COOL or HEAT) by the SW4-2.
(2) In the fan operation conditions, the fan is always operated by 100 percent.
(3) The operation mode display blinks at intervals of 1 second.
5. How to release the emergency operation
(1) Turn off the main power supply.
(2) Turn off the emergency switch (SWE) in the indoor controller board.
(3) Open the CN31 (emergency operation connector) in the outdoor controller board.
(4) Set the SW4-2 on the outdoor controller board as in the right.
Unit operation during emergency operation
Parts name
Compressor
Four way valve
Outdoor fan motor
LEV
Indoor fan motor
OC379F
Operation
Always ON
Changeable with SW 4-2
Max. speed
Full opening
High
Inspections details
Receiving trouble (outdoor unit)
Transmission trouble (outdoor unit)
55
SW4
Heating
ON
1 2 Cooling
SW4
ON
1 2