16
Figure 12. Typical Communication Wiring Diagram (VRF Heat Pump System)
(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
