13
Figure 12. Typical Communication Wiring Diagram (VRF Heat Pump System)
Tightening torque for the terminal screws
•
Use the correct screwdriver for fighting the terminal
screws. If the screwdriver blade is too small, the head
of the screw might be damaged, and the screw will
not be properly tightened.
• If the terminal screws are over tightened, screws
might be damaged.
• Refer to the table below for the tightening torque of
the terminal screws.
•
After wiring, confirm all connections are correct; Then
turn on power supply to the unit.
Table 3. Terminal Screw Tightening Torque
Tightening torque
(lb-ft)
Terminal base of
remote controller/Signal
transmission wire (X2M)
0.58-0.72
Terminal base of power
supply (X1M)
0.87-1.06
Grounding terminal (M4)
1.06-1.43
(PQ)
(PQ)
Outdoor unit
(main unit)
Outdoor unit
(sub1 unit)
Outdoor unit
(sub2 unit)
Install a terminating resistor (Ω120) at the last indoor unit terminals
P
and Q of the daisy chain.
P Q
All shields
of
shielded
cable
connect
to
chassis
GROUND
terminal at Indoor Units.
.
18 GA
.,
stranded,
2-conducto
r
,
shielded
control
wire (polarit
y
sensitiv
e).
T
ypical Wiring Diagram, NEC/CEC and Local Codes apply.
(H1 H2 )
Outdoor Unit Communication Terminal Block
P
Q
H1 H2
X
Y
O
A
K1 K2
(H1 H2 )
(H1 H2 )
Indoor Unit Communication Terminal Block
HA HB 12V COM P
Q
Ground
c
able s
hield
to Indoor Unit chassis
