Connecting The Cables - Mitsubishi Electric CITY MULTI Y Serie Manual De Instalación

10-5-3. Connecting the cables

HP72 to 120T/YNU-A
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L1 L2 L3
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<Notice>
・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.
・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 (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.
Take the procedure below to connect the cables.
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, earth) on the
outdoor units. The indoor-outdoor transmission cable to the indoor unit should be connected to TB3 (M1, M2,
earth) of only one of the outdoor units. Connect the shield to the earth 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.* 1 Connect the shield 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, OS1 and OS2. (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 the control board (main board) on only one of the outdoor units.
④ On the outdoor unit whose power jumper was moved from CN41 to CN40, short circuit the S terminal and the
earth 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.
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Power cables, transmission cables
Ⓑ Daisy-chain (transmission cables only)
Ⓒ Terminal blocks (TB1, TB3, TB7)
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Make an alignment mark.
Ⓔ Install the ring terminals back to back.
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Terminal block with loose screws
Properly installed terminal block
Spring washers must be parallel to the terminal block.
Control box
Power supply terminal block (TB1)
Terminal block for indoor-outdoor transmission
cable (TB3)
Terminal block for centralized control
transmission cable (TB7)