Electrical Work - Mitsubishi Electric MXZ-8C48NA2 Installation Manual

6. Electrical work

6.1. Caution
1 Follow ordinance of your governmental organization for technical standard
related to electrical equipment, wiring regulations and guidance of each electric
power company.
2 Wiring for control (hereinafter referred to as transmission line) shall be (5 cm
[2 inch] or more) apart from power source wiring so that it is not influenced by
electric noise from power source wiring. (Do not insert transmission line and
power source wire in the same conduit.)
3 Be sure to provide designated grounding work to outdoor unit.
4 Give some allowance to wiring for electrical part box of indoor and outdoor
units, because the box is sometimes removed at the time of service work.
5 Never connect the main power source to terminal block of transmission line. If
connected, electrical parts will be burnt out.
6 Use 2-core shield cable for transmission line. If transmission lines of different
systems are wired with the same multiplecore cable, the resultant poor trans-
mitting and receiving will cause erroneous operations.
E
L1 L2 GR
B1 B2 M1
TB1 TB1B TB3
B
C
A
CONDUIT PLATE:
accessory
ø24 knock-out hole
(For transmission wires)
A : Power source
B : Power supply for branch box
C : Screw on the electrical component box
Fig. 6-1
6.3. Wiring transmission cables
1 Types of control cables
1. Wiring transmission cables
Kind of transmission cables Shielding wire CVVS or CPEVS or MVVS
Cable diameter More than 1.25 mm² [AWG 16]
Maximum wiring length Within 200 m [656 ft]
2 Wiring examples
[1] Basic systems
OC:
BC:
A-IC:
OC
MA-RC: MA remote controller
WL-RC: Wireless remote controller
BC
(5-branch type)
B D
A C
A-IC A-IC A-IC A-IC
MA-RC MA-RC
WL-RC WL-RC
F
M2 S M1 M2 S
TB7
D
ø37 knock-out hole
(For power supply wires)
D : Transmission line
E : Screw on the electrical component box for
ground connection (TB3)
F : Screw on the electrical component box for
ground connection (TB7)
Outdoor unit
Branch box
A-Control indoor unit (M, P, S series indoor unit)
BC
(3-branch type)
A
E B C
A-IC A-IC A-IC A-IC
WL-RC WL-RC WL-RC WL-RC
7 Only the transmission line specified should be connected to the terminal block
for outdoor unit transmission.
(Transmission line to be connected with indoor unit : Terminal block TB3 for
transmission line, Other : Terminal block TB7 for centralized control)
Erroneous connection does not allow the system to operate.
8 In case to connect with the upper class controller or to conduct group operation
in different refrigerant systems, the control line for transmission is required
between the outdoor units each other.
Connect this control line between the terminal blocks for centralized control.
(2-wire line with no polarity)
When conducting group operation in different refrigerant systems without con-
necting to the upper class controller, replace the insertion of the short circuit
connector from CN41 of one outdoor unit to CN40.
9 Before turning outdoor unit on, be sure to turn the indoor units and the branch
boxes.
6.2. Control box and connecting position of wiring
(Fig. 6-1)
1. Connect the wiring between the outdoor unit and the branch box to the trans-
mission terminal block (TB3) of the outdoor unit.
Connect the wiring between the outdoor unit and the centralized control system
to the transmission terminal block (TB7) of the outdoor unit.
When using shielded wiring, connect the ground of the shielded wiring to the
shield terminal (S) of the terminal block (TB3) or (TB7).
If the connection of the outdoor unit's transmission power supply connector has
been changed from CN41 to CN42, connect the shield terminal (S) of the termi-
nal block (TB7) to the screw F using the included lead wire.
* The shield (S) terminal of the transmission terminal block (TB3) is connected to
the ground E when the unit is shipped from the factory.
2. Conduit mounting plates are being provided. Remove the knock-out pieces
from the piping cover, pass the power supply and transmission wires through
the appropriate knock-out holes, and connect the wires to the terminal block.
3. The terminal block (TB1B) is for supplying power to the branch box
(208 230 V, max. 6A).
/
4. Fix power source wiring to the terminal block by using buffer bushing for tensile
force (PG connection or the like).
Caution:
Never connect the transmission line for the branch box or the central control
system transmission line to this terminal block (TB1B). If the transmission
lines are connected, the indoor unit, branch box or system controller could
be damaged.
2. MA Remote control cables
Kind of remote control cable Sheathed 2-core cable (unshielded) CVV
0.3 to 1.25 mm² [AWG 22 to AWG 16] (0.75 to
Cable diameter
1.25 mm² [AWG 18 to AWG 16])*
Remarks Within 200 m [656 ft]
* Connected with simple remote controller.
OC
BC
(5-branch type)
B D
A C
A-IC A-IC
MA-RC MA-RC
Note:
The indoor units can be connected
to any of the 5 connectors (5-branch
type) or 3 connectors (3-branch type)
of the branch box.
BC
(3-branch type)
B
E A C
A-IC A-IC A-IC
WL-RC WL-RC WL-RC
en
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