Carrier 40MUAA - Page 21

40MUAA: Installation Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Scenario 3 - Full 24V Communication
This is the preferred method when using a 24V thermostat and when the indoor unit communicates with the outdoor unit via RS485 protocol.
Fig. 51 —Scenario 3
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.
Table 12 — Functional Display
1: Signal
0: No Signal
The terminal input signal is stable for 1 second before confirmation
Mode Priority G Y1 Y/Y2 B W W1 W21 E/AUX DH/DS/BK Display
Shut Down / 0 0 0 0 0 0 0 0 * 00
Fan
7
1000000 0 1
01
Fan 1000000 0 0
Cooling
6
* 1 0 0 0 0 0 0 1 02
Cooling2 * * 1 0 0 0 0 0 1 03
Dehumidification 1 * 1 0 0 0 0 0 0 0 04
Dehumidification 2 * * 1 0 0 0 0 0 0 05
Heating 1
5
*101000 0 1 06
Heating 2 * *11000 0 1
07
Heating 2 * * * * 1 0 0 0 1
Electric Heating 1
3
* 0 0 0 0 1 0 0 *
8
Electric Heating 1 * 0 0 0 0 0 1 0 *
Electric Heating 2 * 0 0 0 0 1 1 0 * 9
Heating 1 + Electric Heating 1
4
*101010 0 1
10
Heating 1 + Electric Heating 1 * 1 0 1 0 0 1 0 1
Heating 2 + Electric Heating 1 * * 1 1 0 1 0 0 1
Heating 2 + Electric Heating 1 * * * * 1 1 0 0 1
Heating 2 + Electric Heating 1 * * 1 1 0 0 1 0 1
Heating 2 + Electric Heating 1 * * * * 1 0 1 0 1
Heating 1 + Electric Heating 2 * 1 0 1 0 1 1 0 1
11Heating 2 + Electric Heating 2 * * 1 1 0 1 1 0 1
Heating 2 + Electric Heating 2 * * * * 1 1 1 0 1
Emergency Heating 1 * * * * * * * 1 * 12
Heating Zone Control
2
*1010** 0 0
13Heating Zone Control * * 1 1 0 * * 0 0
Heating Zone Control * * * * 1 * * 0 0
Outdoor Unit
RCGY1Y2BW W1W2EDHL
24V Thermostat
Indoor Unit Display Board
RCGY1Y2BWW1W2EDHL S1S2
S1 S 2RCY1Y2BWDL
Control
Board
1 2 3 4
ON
SW1