Toshiba MMY-MUP0801HT8P-TR Service Manual page 253

(3) Change the connection of wiring as shown in the below.
Outdoor Unit (22, 24HP)
Model: MMY-MUP2201", MUP2401"
1. When compressor No.1 is failure : No change the connection of wiring
2. When compressor No.2 is failure : Connection of wiring is changed as shown below.
Compressor
P.C.board 1
CN21
CN852
CN102
CN22
CN103
Compressor
P.C.board 2
(4) Turn on the power supply to all the units connected to the system.
This is the end of compressor backup operation setting.
Change the connection of wiring which is connected to the
CN21, CN22 and CN103 of "Compressor P.C.board 1" and
"Compressor P.C.board 2".
• Change to CN21 of P.C.board 1 from CN21 of P.C.board 2.
• Change to CN22 of P.C.board 1 from CN22 of P.C.board 2.
• Change to CN103 of P.C.board 1 from CN103 of P.C.board 2.
Remove the connector from "Compressor P.C.board 1"
• Remove the connector of CN102
• Remove the connector of CN852
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