Carrier XCT7 40VU0051-7E-QEE Installation And Owner's Manual page 26

Electrical Wiring
Signal Wiring Drawing
P Q A B C
(AC machine)
P Q A B C
P Q A B C
P Q A B C
P Q A B C
Outdoor units have parallel connections via three lines with polarity. The main unit, central control, and all indoor units have
parallel connections via two lines without polarity.
There are three connecting ways between the line control and indoor units:
A.One wired controller controls multiple units, i.e. 2-16 indoor units, as shown in the above figure(1-5 indoor units).The
indoor unit 5 is the line-controlled master unit and others are the slave units. The remote controller and the master
unit(directly connected to the indoor unit of wired controller) are connected via three lines with polarity. Other indoor units
and master unit are connected via two lines or three lines with polarity (If the PCB of indoor is DC, the wired controller
needs to be connected to ABC, while the PCB of indoor is AC, the wired controller only connects to BC.). SW01 on the
mater unit of line control is set to 0 while SW01 on the slave units of line control are set to 1,2,3 and so on in turn. (Please
refer to the code setting page).
B. One wired controller controls one indoor unit, as shown in the above figure (indoor units 6–19). The indoor unit and
the wired controller are connected via three lines with polarity.
C. Two wired controllers control one indoor unit, as shown in the figure (indoor unit 20). Either of the controllers can be
set to be the master controller while the other is set to be the auxiliary controller. The master wired controller and
indoor units, and the master and auxiliary wired controller are connected via three lines with polarity.
(AC machine) (DC machine)
P Q A B C P Q A B C
P Q A B C P Q A B C
P Q A B C P Q A B C
P Q A B C P Q A B C
(DC machine)
P Q A B C
P Q A B C
P Q A B C
P Q A B C
18
(Master
DC or AC)
P Q A B C
P Q A B C
P Q A B C
P Q A B C