Step 9 - Third Party Thermostat Installation - Carrier 40MBAA Installation Instructions Manual

Step 9 - Third Party Thermostat Installation

The indoor unit has a 24V that provides flexibility, functionality and
control by a 3rd party thermostat* (field supplied).
1. Run the thermostat wiring from the thermostat to the 24V interface
using connection R and C on CN15 and Y, W, G on CN19. see Fig.
64.
2. The 24V Interface Dip Switches come pre-configured for normal
operation and easy installation. Dip Switch 2-1 can be configured to
make the system operate in the COOLING ONLY mode. Dip
Switch 3-1 can be configured for the DRY mode when not using
auxiliary heat.
Table 13 — DIP Switch 2-1
SW2-1
ON COOLING ONLY
OFF
Table 14 — DIP Switch 3-1
SW3-1
ON
OFF
3. Configure the thermostat to operate as a single stage cooling and
heating (DO NOT configure the thermostat as Heat Pump).
*A conventional 5-wire thermostat is required. A 2 Heat/ 1 Cool thermostat is
required for electric heat application.
24V Board
Fig. 59 — Indoor Unit Control Box Size 24
24V
Interface
Board
24V Transformer
Fig. 60 — Indoor Unit Control Box Sizes 36 - 48
IM-40MBAA-02
RESULT NOTE
HEAT PUMP Default
RESULT NOTE
DRY Mode
Used on future
Default
applications
Main Board
Main Terminal Board
Main
Board
Specifications subject to change without notice.
LED Display
The control displays active faults codes on the LED display. When the
control displays the fault code and the LED flashes quickly, there is
something wrong with the system. Refer to "TROUBLESHOOTING"
for the detailed fault codes.
Temperature Sensor
The unit has one temperature sensor, which is called a Pipe
Temperature Sensor. If the temperature sensor is damaged, the system
shuts down and the LED flashes repeatedly.
Connector
Table 15 — Connector
Connector
Y
W
G
AUX/DRY
Table 16 — Mode Setting
Y W G AUX/DRY
√ X * *
X √ * X
X √ * √
X X √ X
√ √ * *
X X X X
X X * √
Table 17 — Fan Speed Setting
UNIT ON/OFF
√
√
X
√
X
* ON or OFF
THERMOSTAT
INDOOR UNIT OUTPUT WITH 24VAC 1.5A
Fig. 61 — Cooling Only System Wiring Diagram
Purpose
Cooling
Heating
Fan-Auto Speed
Aux-Heat/Dry
SETTING MODE
Cooling
Heating (without aux-heater)
Heating (with aux-heater)
Fan only
OFF
OFF
Dry
G SETTING FAN SPEED
X Auto Fan Speed
√ Auto Fan Speed
X Fan OFF
ON
OFF
INDOOR UNIT
19