Toshiba MMU-AP0091H service manual Refrigerant recovery procedure backup, 193

(Refrigerant recovery procedure (backup))

If the power of the malfunctioning unit cannot be turned on, the PMV cannot be opened, therefore the amount of recovered refrigerant decreases compared with the usual pump down operation.

Using a refrigerant recovery device, recover the remaining gas in the unit and measure the recovered refrigerant, as the same amount of refrigerant will be required to be recharged after the repair.

Procedure

[Set up the malfunctioning outdoor unit as follows]

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.Fully close the service valve of the liquid pipe in the malfunctioning outdoor unit (keep the service valves of the gas pipe and the balance pipe open).

[Set up the unit selected as the header unit as follows]

3.Set up the rotary SW01/02/03 to 2/5/1 on the interface P.C. board of the selected header outdoor unit, [C.] [ ] is displayed on 7-segment display.

4.Push SW04 for 5 seconds or more, the system operates in the test cooling operation when [C.] [ C] is displayed on the 7-segment display.

Set up the rotary SW01/02/03 to 1/2/2 on the interface P.C. board of the selected header outdoor unit to display the low pressure data (MPa) on the 7-segment display.

5.Push the SW04 for 2 seconds, the low pressure (MPa) is displayed on 7-segment.

	Header unit	Unit selected as
1	with trouble	the header unit
Connect check joint of the liquid pipe and
low pressure side by the gauge manifold,
and then purge air inside of the hose.
2
Close fully service valve of the liquid pipe.
(Keep gas valve of pipe and balance pipe
opened.)
		Interface P.C. board
4 Set rotary SW01/02/03 to 2/5/1.
[C. ] [	] areØdisplayed.

Push SW04 for 5 seconds or more. 5 [C. ] [ –C] are displayed (TestØcooling operation starts.)

6 Low pressure (MPa) is displayed by pushing the push SW04. Pd ÆPs ÆTd1 ÆTd2 ÆTS ÆTE ÆC — C

6.Fully close the service valve of the gas pipe on the malfunctioning outdoor unit approximately 10 minutes after the system has started.

[Select an outdoor unit for pressure adjustment as follows]

7. Select the header unit as the unit for pressure adjustment.

[Set up all other outdoor units as follows]

8.Fully close the service valves of the other outdoor unit balance pipes.

Only keep the service valves of the balance pipes of the header unit and the malfunctioning unit fully open.

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