Unit Wiring - Fujitsu Airstage Uty-Vdgu Installation Manual

(Crossover wiring of power supply)
DX-kit (Control unit)
Power supply Power supply
Pull box
Breaker2
Breaker1
Power supply
Disconnect switch shall be installed between each unit and pull box.

7.3. Unit wiring

Before attaching the cable to terminal block.
7.3.1. Power supply cable and Drain pump signal cable
Adjust the length of power supply cable to avoid excessive tension with referring figure
below.
Earth (ground)
wire
Decide the peeling length of the covering for the power supply cable and the drain pump
signal cable according to the conditions for connecting to the terminal.
A. For solid core wiring
(1) To connect the electrical terminal, follow the below diagram and connect after looping
it around the end of the cable.
(2) Use the specified cables, connect them securely, and fasten them so that there is no
stress placed on the terminals.
(3) Use an appropriate screwdriver to tighten the terminal screws. Do not use a screw-
driver that is too small, otherwise, the screw heads may be damaged and prevent the
screws from being properly tightened.
(4) Do not tighten the terminal screws too much, otherwise, the screws may break.
(5) See the table for the terminal screw tightening torques.
(6) Please do not fix 2 power supply cables with 1 screw.
Strip 1 in
(25 mm)
Screw with
special washer
Cable
Cable end (Loop)
Terminal block
When using solid core cables, do not use the ring terminal. If you use the solid core
cables with the ring terminal, the ring terminal's pressure bonding may malfunction and
cause the cables to abnormally heat up.
B. For strand wiring
(1) Use ring terminals with insulating sleeves as shown in the figure below to connect to
the terminal block.
(2) Securely clamp the ring terminals to the cables using an appropriate tool so that the
cables do not come loose.
(3) Use the specified cables, connect them securely, and fasten them so that there is no
stress placed on the terminals.
(4) Use an appropriate screwdriver to tighten the terminal screws. Do not use a screw-
driver that is too small, otherwise, the screw heads may be damaged and prevent the
screws from being properly tightened.
(5) Do not tighten the terminal screws too much, otherwise, the screws may break.
(6) See the table for the terminal screw tightening torques.
(7) Please do not fix 2 power supply cables with 1 screw.
Indoor unit Indoor unit
Power supply
Pull box
: Disconnect switch
Conduit connector
5-1/2 in (140 mm)
5-1/2 in (140 mm)
Loop
Screw with
special washer
Cable end
(Loop)
Cable
WARNING
Strip 3/8 in
(10 mm)
Screw with special
washer
Cable
Ring terminal
Terminal block
Use ring terminals and tighten the terminal screws to the specified torques, otherwise,
abnormal overheating may be produced and possibly cause heavy damage inside the
unit.
Tightening torque
M4 screw
(Power supply/L1, L2 (N), GND)
7.3.2. Transmission cable, Remote controller cable and External
interface cable
Transmission cable
Shielded cable
(no film)
Remote controller cable
For 3-wire type
1 in (25 mm)
External interface cable
Decide the peeling length the covering for the external interface cable according to the
conditions for connecting to the terminal.
Fig. A
GOOD
Different diameter
Tighten the terminal screws to the specified torques, otherwise, abnormal overheating
may be produced and possibly cause heavy damage inside the unit.
Terminal number
M3 screw
(Transmission/X1, X2)
(Remote controller/ Y1, Y2, Y3)
To peel the film from the lead cable, use a dedicated tool that will not damage the
conductor cable.
When installing a screw on the terminal block, do not cut the cable by overtightening the
screw. On the other hand, an under tightened screw can cause faulty contact, which will
lead to a communication failure.
Ring terminal
Sleeve
Screw with spe-
cial washer
Ring
terminal
Cable
WARNING
11 to 16 lbf·in
(1.2 to 1.8 N·m)
1 in (25 mm)
1-9/16 in (40 mm)
For 2-wire type
1 in (25 mm)
PROHIBITED
Connect to 1 side
WARNING
Tightening torque
4.4 to 5.3 lbf·in
(0.5 to 0.6 N·m)
CAUTION
En-8