Toshiba SHRM R410A Quick Reference page 83

(6) Approx. 10 minutes after the system starts up, fully close the gas pipe service valve of the failed outdoor unit.
(7) Push SW04 of the failed outdoor unit to have pressure data (MPa) displayed.
(The display switches each time SW04 is pushed.)
Display Example
[rd] [...11]
Initial display
[Selection of outdoor unit for pressure adjustment]
(8) Of all outdoor units operating in the pump-down mode, select the one with the lowest unit No. as an outdoor unit
for pressure adjustment.
Identifying Unit No.
The unit No. is the number displayed on the 7-segment display when SW01/02/03 are set to 1/1/1.
([U#] [– – –]: # represents the unit No.)
[Setup of outdoor units other than unit for pressure adjustment and failed unit]
(9) Leaving the balance pipes of the unit for pressure adjustment and the failed unit fully open, fully close the
balance pipe service valves of all other outdoor units.
[Setup of outdoor unit for pressure adjustment]
(10) Set SW01/02/03 on the interface P.C. board of the outdoor unit for pressure adjustment to 1/2/2.
(11) As the low-pressure sensor output is displayed on the 7-segment display, adjust the pressure to around 0.12
MPa by slowly closing the gas pipe service valve, with checking pressure data.
(12) Compare the low-pressure sensor outputs of the failed unit with that of the unit for pressure adjustment, and
wait until the two pressure readings become almost the same. After letting the system continue operating for a
while longer, fully close the gas pipe service valve of the unit for pressure adjustment.
[Setup of failed outdoor unit]
(13) When the low-pressure sensor output of the failed outdoor unit falls below 0.10MPa, fully close the balance
pipe packed valve, and push SW05 on the interface P.C. board to finish the pump-down operation.
(14) Turn off the power supply to all the outdoor units, and recover the residual refrigerant in the outdoor unit
using a refrigerant recovery device. Be sure to measure the amount of recovered refrigerant. (This is necessary
to determine how much additional refrigerant will be needed after the completion of the repair.)
The outdoor units operating in the pump-
down mode, is selevted to the outdoor
unit for pressure adjustment.
Unit for pressure adjustment
(9)
Set SW01/02/03 to
1/2/2 to have low
pressure sensor
output displayed.
[Ps] [###]
This is the end of the refrigerant recovery operation.
Set SW01/02/03 of the failed outdoor unit and the outdoor unit for pressure adjustment back to 1/1/1.
[Pd] [1.20]
High-pressure sensor output
(8)
(10)
While monitoring low-pressure
sensor output, adjust pressure to
around 17 psi (0.12 MPa) by slowly
closing suction gas pipe service valve.
(11)
Wait until low-pressure sensor
outputs of failed outdoor unit and
outdoor unit for pressure
adjustment become almost
identical, and, after letting system
continue operating for while longer,
fully close gas pipe service valve.
[Ps] [1.20]
Low-pressure sensor output
(6)
Approx. 10 minutes after system startup,
fully close the suction gas pipe service
valve.
Failed outdoor unit
(7)
Push SW04 to have
When low-pressure sensor output of failed
low-pressure sensor
outdoor unit falls below 14.5 psi (0.10 MPa),
output displayed
fully close balance pipe packed valve.
[Ps] [###]
Push SW05 to finish pump-down operation.
Turn off power supply to all outdoor units at
source, and recover residual refrigerant in
outdoor unit using refrigerant recovery device.
Measure amount of recovered refrigerant.
82
(12)
(13)