Backup Operation Of The Outdoor Unit Is Being Executed; Setup For The Unit Selected As Header Unit - Toshiba Super MMU-AP0091H Service Manual

(Backup operation of the outdoor unit is being executed)

<Outline>
When the power supply of the outdoor unit cannot be turned on under condition that a backup operation is set up for the
troubled outdoor unit, correct refrigerant recovery procedure is different. Try to recover refrigerant in the following proce-
dure.
However in the case of outdoor backup operation in cooling season or the troubled unit ON during outdoor backup
operation, recover the refrigerant in the work procedure in which the abovementioned "Outdoor Unit Backup Setup" is not
performed.
If the backup for the outdoor unit is set up under condition that the troubled unit is turned on, return the communication
connector [CN03] between outdoor units on the interface P.C. board of the corresponding unit to the original status, reset
the power supply, and then start the recovery operation in the above work procedure.
Note) If the power of the troubled unit cannot be turned on, the solenoid valve PMV of the unit cannot be turned on.
Therefore the refrigerant recovery amount decreases compared with the usual pump-down operation.
Using a refrigerant recovery device, recover the remaining gas in the unit and measure the recovered amount.
<Work procedure>
[Setup for the troubled outdoor unit]
1. Using a gauge manifold, connect the check joint of the liquid pipe and the low-pressure side, and then purge air in the
hose. (To recover refrigerant in the heat exchanger and the liquid tank)
2. Close fully the service valve of the liquid pipe of the outdoor unit with trouble.
(Keep service valve of the gas pipe and the balance pipe opened.)

[Setup for the unit selected as header unit]

3. Set up the rotary SW01/02/03 to 2/5/1 on the interface P.C. board of the header outdoor unit, and push the push SW04
for 5 seconds or more after [C. ] [ ] have been displayed on 7-segment display section.
4. The system operates in the test cooling operation after [C. ] [ – C] have been displayed on 7-segment display section.
5. Set up the rotary SW01/02/03 to 1/2/2 on the interface P.C. board of the header outdoor unit to display the low-pressure
data (MPa) on 7-segment display section.
Connect check joint of the liquid pipe and
low pressure side by the gauge manifold,
and then purge air inside of the hose.
Close fully service valve of the liquid pipe.
(Keep gas valve of pipe and balance pipe
opened.)
4 Set rotary SW01/02/03 to 2/5/1.
Push SW04 for 5 seconds or more.
4 [C. ] [ –C] are displayed (Test cooling operation starts.)
5 Low pressure (MPa) is displayed by pushing the push SW04.
Pd Ps
6. Close fully the service valve of the gas pipe on the troubled outdoor unit approx. 10 minutes after the system has
started.
[Setup for outdoor unit for adjustment of pressure]
7. Select the header unit as the unit for pressure adjustment.
[Setup for outdoor units other than header unit and troubled unit]
8. Keep only the balance pipes of the header unit and the troubled outdoor unit fully opened, and close fully the service
valves of other outdoor unit balance pipes.
1
2
[C. ] [ ] are displayed.
Td1 Td2 TS TE C — C
Header unit
with trouble
Interface P.C. board
236
Unit selected as
the header unit