Toshiba R410A Service Manual page 192

6. Fully close the service valve in the gas pipe of the malfunctioning outdoor unit approximately 10 minutes after
the system has started.
7. Push SW04 of the malfunctioning outdoor unit, to display the pressure data (MPa).
For each successive push of SW04, the data display changes as shown in the example below.
Display Example
[Select an outdoor unit for pressure adjustment as follows]
8. When operating the pump down mode, the outdoor unit which has the lowest unit number is selected as the
outdoor unit for the pressure adjustment.
Unit No.
When SW01/02/03 are set to 1/1/1, the number displayed on the 7-segment display indicates the
unit number ([U#][---]: # indicates the unit number)
[Set up all other outdoor units as follows]
9. Fully close the service valves of all the other outdoor unit balance pipes. Only keep the service valves of the
balance pipes of the unit in which the pressure adjustment will be made and the malfunctioning unit fully open.
[Setup for outdoor unit for adjustment of pressure]
10. Set up the rotary SW01/02/03 to 1/2/2 on the interface P .C. board of the outdoor unit in which the pressure
adjustment will be made.
11. The low pressure (Ps) data is displayed on the 7-segment display.
Slowly close the service valve of the gas pipe and adjust so that a pressure of 0.12 MPa is displayed.
12. When the low pressure (Ps) of the malfunctioning outdoor unit is almost the same as that of the unit in which
the pressure adjustment has been made, fully close the service valve of the gas pipe in the unit which the
pressure adjustment was made.
[Set up the malfunctioning outdoor unit as follows]
13. When the pressure of the malfunctioning outdoor unit is below 0.1 MPa, fully close the service valve of the
balance pipe and push SW05 on the interface P .C. board to finish the pump down operation.
14. Turn off the power supplies to all of the outdoor units and use a refrigerant recovery device to recover the remaining
refrigerant in the outdoor unit, in which the pump down operation has been completed. Be sure to measure the
recovered refrigerant, as the same amount of refrigerant will be required to be recharged after the repair.
9
Fully close the balance pipes of
the outdoor units except the
unit for pressure adjustment
and unit with the malfunction.
When low pressure of the malfunctioning outdoor
unit is below 0.10 MPa, fully close the service valve
of the balance pipe.
Turn off the power of all the outdoor units.
Using a recovery device, reclaim the remaining
refrigerant in the outdoor unit in which pump-down
operation has finished and measure the amount.
Return all rotary switches SW01/02/03 to 1/1/1.
[rd] [ 11]
Initial display
Fully close the service valve of
the gas pipe approx. 10 minutes
after the system has started.
Malfunctioning outdoor unit
The low pressure
is displayed by
pushing SW04.
[Ps] [###]
13
14
[Pd] [1.20]
High pressure
6
The lowest number
outdoor unit is
selected as the
outdoor unit for
7
pressure adjustment.
The low pressure is
displayed by setting
SW01/02/03 to 1/2/2.
Close service valve of the gas pipe gradually
while checking the low pressure, and then
adjust the pressure to 0.12 MPa.
When low pressure of the malfunctioning
outdoor unit and low pressure of the outdoor
unit for pressure adjustment becomes almost
same, fully close the service valve of gas pipe
on the outdoor unit for pressure adjustment
192
[Ps] [1.20]
Low pressure
8
10
[Ps] [###]
11
12