Connection Diagrams - Carrier 40MUAAQ18XB3 Service Manual

40MUAA: Service Manual

CONNECTION DIAGRAMS

Scenario 1 - Non-Polarity RS485 Communication + 24V Thermostat
This is the preferred method when using a 24V thermostat and when the indoor unit communicates with the outdoor unit via RS485 (S1/S2) protocol.
NOTE: After the serial number (0223V26809), the Auto Discovery feature is available.
Scenario 2 - Non-Polarity RS485 Communication
This is the preferred method of control with wired controller KSACN1001AAA (Not included)
Scenario 3 - Full 24V Communication
This method allows for 24 communication between a 24V thermostat, the indoor unit and the outdoor unit.
NOTE: For scenarios 2 and 3 - The use of shielded communication or thermostat wire is not required but is recommended
where separation from high voltage conductors cannot be maintained, or in areas with high electrical noise. The shield
and drain conductor must be grounded at the outdoor unit and stripped back and taped at the indoor unit. Grounding
at both ends results in an increase of noise transmitted onto the signal wires.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Indoor Unit Display Board
R C G Y1 Y2 B W W1W2 E DH L
R C G Y1 Y2 B W W1W2 E DH L
24V Thermostat
Fig. 11 — Scenario 1
WARNING
Refer to the wiring nameplate for the wiring method.
DO NOT connect 24V AC to S1-S2, as this will damage the
system.
Wired
Indoor Unit Display Board
Controller
HA HB R C L G Y1
Y1/Y2
HA HB
Wired
Controller
Fig. 12 — Scenario 2
Indoor Unit Display Board
R C G Y1 Y2 B W W1W2 E DH L
R C G Y1 Y2 B W W1W2 E DH L
24V Thermostat
Fig. 13 —Scenario 3
Control
Board
S1 S2
R C Y1 Y2 B W D L S1 S2
Outdoor Unit
Control
Board
B W W1W2 E DH S1 S2
R C Y1 Y2 B W D L S1 S2
Outdoor Unit
Control
Board
S1 S2
R C Y1 Y2 B W D L S1 S2
Outdoor Unit
10
SW1
ON
1 2 3 4
SW1
ON
1 2 3 4
SW1
ON
1 2 3 4