Toshiba MMY-MAP0806HT7(J)P, Service Manual

Page: 246 / 350

9-3-2. Header outdoor unit backup operation setting
(failure of header outdoor unit)
<Work procedure>
(1) Turn off the power supply to all the units connected to the system at the source.
[Setup of failed header outdoor unit]
(2) Fully close the gas pipe service valve of the failed outdoor unit.
(3) Leave the service valves of the liquid and balance pipes fully open (to prevent refrigerant stagnation in the failed
outdoor unit).
However, if there is a leakage from an outdoor PMV (unable to close), fully close the liquid pipe service valve.
(4) <In case of fault in compressor, electrical part, I/F P.C. board, or IPDU P.C. board>
From this point on, keep the power supply to the failed unit off.
<In case of fault in refrigerating circuit or related part (pressure sensor, temperature sensor, refrigerating cycle
part, or fan system part)>
Disconnect the connector [CN03] for outdoor-outdoor communication (BUS2) provided on the interface P.C.
board.
[Selection of new header unit]
(5) Select a new header unit from the follower units on the basis of the following criteria:
• If only one follower unit is connected, select it as the header unit.
• If two follower units are connected, select the follower unit that is nearest to the failed header unit.
[Setup of new header unit]
(6) Set SW13 and SW14 on the interface P.C. board same as the setting of failed header unit (refrigerant line
address setting).
(7) Turn on Bit 2 of SW09 on the interface P.C. board. (Setting to prevent connected indoor unit capacity over error.
(E16))
Setup of failed follower outdoor unit
(2)
(3)
(4)
CN03 BUS2
Fully close gas pipe
service valve.
Leave service valves of liquid and balance pipes fully open.
(if there is leakage from outdoor PMV, fully close liquid pipe.)
In case of fault in refrigerating circuit
or related part, disconnect BUS2
communication connector [CN03] on
interface P.C. board.
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