Amana AVZC18 Series Service Instructions Manual page 16

SERVICING
However, the thermostat may also request and receive informa-
tion from both the indoor and outdoor units. This information
may be displayed on the CT thermostat. The indoor and outdoor
units also interact with one another. The outdoor unit may send
commands to or request information from the indoor unit. This
two-way digital communications between the thermostat and sub-
systems (indoor/outdoor unit) and between subsystems is the key
to unlocking the benefits and features of the ComfortNet system.
Two-way digital communications is accomplished using only two
wires. The thermostat and subsystem controls are powered with
24 VAC Thus, a maximum of 4 wires between the equipment and
thermostat is all that is required to operate the system.
CTK04 W
IRING
NOTE: A removable plug connector is provided with the control
to make thermostat wire connections. This plug may be removed,
wire connections made to the plug, and replaced. It is strongly
recommended that multiple wires into a single terminal be twisted
together prior to inserting into the plug connector. Failure to do
so may result in intermittent operation.
Typical 18 AWG thermostat wire may be used to wire the system
components. However, communications reliability may be im-
proved by using a high quality, shielded, twisted pair cable for the
data transmission lines. In either case, 250 feet is the maximum
length of wire between indoor unit and outdoor unit, or between
indoor unit and thermostat. Please use a thermostat model later
than CTK04AB.
16
T -W O , F
WO IRE UTDOOR OUR
Low voltage wiring consists of two wires between the indoor unit
and outdoor unit and four wires between the indoor unit and the
thermostat. The required wires are: (a) data lines, 1 and 2; (b)
thermostat "R" (24 VAC hot) and "C" (24 VAC common).
1 2 R C
1 2 R C
1 2 R C
System Wiring
System Wiring Using Four-Wires
Two wires only may be utilized between the indoor and outdoor
units. For this wiring scheme, only the data lines, 1 and 2, are
required between the indoor and outdoor units.
-W I W
IRE NDOOR IRING
CTK04
Thermostat
Compatible
Air Handler
Integrated Control Module
Compatible HP
Integrated Control Module