Electrical Work - Mitsubishi Electric PAC-MKA50BC Installation Manual

8. Electrical work

A
Fig. 8-1
F E G
D
A
Electric cover
B
Conduit plate
C
Wiring
D
Controller board
E
Terminal block: TB5
F
Terminal block: TB2B <To outdoor unit>
G
Terminal block: TB3A-TB3E
<To indoor unit>
Fig. 8-3
D
G
E
H
F
A
Fig. 8-5
M
J
K
L
Fig. 8-6
5 ft or less
L
Fig. 8-8
C
B
Fig. 8-2
H~O
H
Earth Terminal <To outdoor unit>
J
Earth Terminal <For TB3A>
K
Earth Terminal <For TB3B>
L
Earth Terminal <For TB3D>
M
Earth Terminal <For TB3C>
N
Earth Terminal <For TB3E>
O
Earth Terminal <To other branch
box>
Fig. 8-4
G
B
C
N
Fig. 8-7
Support
Cautions for electrical work.
Warning:
• Always use dedicated circuits with breakers, and at the rated voltage.
Power supply circuits with insuf cient capacity, and bad workmanship
during installation, may result in electric shock or re.
Caution:
• Be sure to establish an earth. Do not earth the unit to a utility pipe,
arrester, or telephone earth.
Incomplete earth may cause electrical shock. A high surge current from
lightning or other sources may cause damage to the air conditioner.
• Use the speci ed electrical wiring and ensure that it is connected prop-
erly, and that it is not under tension.
Failure to follow these requirements may result in broken wiring, heating,
or re.
Before turning Branch Box on, be sure to set the switches.
To turn the power on, turn on the Branch Box then the outdoor unit, in
that order.
(In case power supplies for Branch Box and outdoor unit are separated)
Wiring connecting branch box and outdoor unit, and branch box and
indoor units, functions as both power supply and signal cable. Connect
this wiring in accordance with the terminal block numbers to ensure
correct polarity.
Ensure that the appropriate refrigerant piping and electrical wiring are
connected to each indoor unit. Incorrect wiring will interfere with the
correct operation of the unit.
Connect refrigerant pipes and connection wires to the appropriate ports
marked with matching alphabets (Ex. A, B, C, D, E) on this unit.
First, connect the power supply cable from the outdoor unit.
Always fix each ground wire separately with a ground screw.
To prevent that wiring installed in the ceiling is chewed by rats etc., it
should be installed in wiring conduit.
1. Remove the electric cover. (Fig. 8-1)
2. Remove the conduit cover.
3. Pass the wiring into the branch box through the conduit plate and fix with
the conduit plate. (Refer to 8.1)
4. Firmly connect each wire to the appropriate terminal block. (Fig. 8-9)
5. Set dip sw. (Refer to 8.3)
6. Replace the electric cover.
8.1. When using wiring conduit (Fig. 8-5,6,7)
Replace the horizontal cover when the wiring conduit has been xed in place.
A
Electric cover
B
Wiring
C
Nut 1/2" (procure locally)
D
Wiring conduit (For TB3A, TB3B)
E
Wiring conduit (For TB3C, TB3D)
F
Wiring conduit (For TB3E)
G
Wiring conduit (For TB2B)
Caution:
0
• When installing the conduit plate
B
are necessary for wiring .
Cutting out unnecessary knockout holes may cause damage due to the in-
vasion of small creatures and the like.
• When cutting out the knockout holes on the conduit plate, beware that nei-
ther deformation nor distortion occurs on the plate.
Also, when installing the conduit plate, beware that no gap exists between
the plate and the conduit pipes or the conduit holes, otherwise it may cause
failure of the controller board due to the invasion of small creatures or in-
sects.
(Fig. 8-6)
To divide the wirings of each terminal block into 2 branches outside the
branch box, use 2-branch wiring conduits
Caution:
To avoid excessive strain on the branch box, support the conduit pipe
one or more support(s) 1.5 m [5 ft] or less from the branch box.
Refer to Fig. 8-8 as an example.
H
Wiring conduit (For TB5B)
J
0
Conduit plate
K
Conduit hole
L
Conduit pipe
M
Controller board
N
2-branch wiring conduit
(procure locally)
, cut out only the knockout holes that
N
. (Fig. 8-7)
L
with
9