10-5-3. Connecting the cables
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L1 L2 L3
Ⓐ
Ⓐ
Ⓓ
Ⓑ
Ⓑ
Ⓒ
Ⓓ
Ⓔ
Ⓐ
Ⓔ
Ⓒ
・Connect the cables respectively to the power supply terminal block and the transmission terminal block. Erroneous connection does not allow
the system to operate.
・Never connect the power cable to the transmission terminal block. If connected, electrical parts will be damaged.
・When connecting cables to TB7, check that the voltage is 20 VDC or below.
・Transmission cables should be (5 cm (2 in) or more) apart from the power cable so that it is not influenced by electric noise from the power
cable. (Do not put the transmission cables and the power cable in the same conduit.)
・Follow the tightening torque for each screw type as shown below. Be careful not to use excessive torque as this could damage the screw.
Terminal block (TB1, TNU (M8 screw): 10–13.5 [N·m], YNU (M6 screw)): 2.5–2.9 [N·m]
Terminal block (TB3, TB7 (M3.5 screw)): 0.82–1.0 [N·m]
・When tightening the screws, do not push the driver strongly to avoid damaging the screw.
・Make an alignment mark with a permanent marker across the screw head, washer, and terminal after tightening the screws.
① Connect the indoor-outdoor transmission cable to TB3.
If multiple outdoor units are connected to the same refrigerant system, daisy-chain TB3 (M1, M2, ground) on the outdoor units. The indoor-
outdoor transmission cable to the indoor unit should be connected to TB3 (M1, M2, ground) of only one of the outdoor units. Connect the
shield to the ground terminal.
② Connect the centralized control transmission cables (between the centralized control system and the outdoor units of different refrigerant systems) to TB7.
If multiple outdoor units are connected to the same refrigerant system, daisy-chain TB7 (M1, M2, S) on all outdoor units.*
to the S terminal.
*1 If TB7 on the outdoor units in the same refrigerant system are not daisy-chained, connect the centralized control transmission cable to TB7 on the OC. If the OC is out of order, or if
centralized control is being conducted during a power supply shut-off, daisy-chain TB7 on the OC and OS. (In the case that the outdoor unit whose power jumper CN41 on the control
board has been replaced with CN40 is out of order or the power is shut-off, centralized control will not be conducted even when TB7 is daisy-chained.)
③ When a power supply unit is not connected to the centralized control transmission cable, move the power jumper from CN41 to CN40 on only
one of the outdoor units (except TNU model). When the System controller is connected to TB7 side and TNU outdoor unit model is used,
connect a power supply unit to TB7 side. If a power supply unit cannot be used, connect the System controller to TB3 side. Up to three
System controllers can be connected to TB3 side.
④ On the outdoor unit whose power jumper was moved from CN41 to CN40, short circuit the S terminal and the ground terminal.
⑤ Connect terminals M1 and M2 of the transmission terminal block on the indoor unit that has the lowest address in the group to the terminal
block on the remote controller.
⑥ When a system controller is connected, set SW5-1 on all outdoor units to ON.
⑦ Fix the cables securely in place with the cable strap below the terminal block.
WT09112X02
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Ⓓ
Terminal block with loose screws
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Properly installed terminal block
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Spring washers must be parallel to the terminal block.
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Power cables, transmission cables
Daisy-chain (transmission cables only)
Terminal blocks (TB1, TB3, TB7)
Make an alignment mark.
Install the ring terminals back to back.
Control box
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Power supply terminal block (TB1)
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Terminal block for indoor-outdoor transmission
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cable (TB3)
Terminal block for centralized control
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transmission cable (TB7)
GB-36
Connect the shield
1