Toshiba MMU-UP0051MH-E(TR) Service Manual page 131

[2] P.C. Board for indoor unit servicing replacement procedures (e.g. MCC-1643)
Step1 Replace the P.C. board to the P.C. board for indoor unit servicing.
At this time, perform the same setting of the jumper wire (J01, J08, J09) setting (cut), switch
SW501, (short-circuit) connector CN34 as the setting of the P.C. board before replacement.
Connector (CN504)
for drain pump
CN504
(White)
Step2 It is necessary to set indoor unit to be exchanged: Remote controller = 1 : 1
Based upon the system configuration, turn on power of the indoor unit with one of the following items.
1) Single (Individual) operation. Turn on power of the indoor units and proceed to [3].
2) Group operation
A) In case that power of the exchanged indoor unit only can be turned on
Turn on power of the exchanger indoor unit only and proceed to [3].
B) In case that power of the indoor units cannot be turned on individually (Case 1)
a) Remove temporarily the group wire connected to the terminal blocks A and B of the indoor
unit.
b) After connecting the remote controller wire only to the removed terminal block, turn on
power of the indoor units and proceed to [3].
* When the above methods cannot be used, follow to the two cases below.
C) In case that power of the indoor units cannot be turned in individually (Case 2)
a) Remove all CN41 connectors of the indoor units in the same group except those of the
exchanged indoor unit.
b) Turn on power of the indoor units and proceed to [3].
* After [3] operation has finished, be sure to return the temporarily removed group wire or
CN41 connector to the original connection.
(Case 1)
Indoor unit
P.C. board
A B
Group wire
If the plug for short-circuit is attached on the P.C. board
before replacement, attach it on the P.C. board replaced.
CN34
(Red) SW501
J08
J01
J09
Service P.C. board of
Indoor unit the unit to be changed
A B
Remove the group wire
of the terminal blocks
Remote A and B of the changed
controller indoor unit and then install
the remote controller only.
CN01
(BLU)
Indoor unit
P.C. board
CN41
A B
Group wire
Remove CN41 connectors of the
indoor units other than the units
to be changed in the same group.
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Attach reactor's plug
to connector CN01
(Case 2)
Service P.C. board of
Indoor unit the unit to be changed
A B A B
Remote
controller