Thermostat Wiring - Carrier 50YFV Installation, Operation And Maintenance Instructions

R e s i d e n t i a l D i g i t a l P a c k a g e d U n i t s G T- P B S e r i e s - 6 0 H z P u r o n
Thermostat Installation
The thermostat should be located on an interior wall in a
larger room, away from supply duct drafts. DO NOT locate
the thermostat in areas subject to sunlight, drafts or on
external walls. The wire access hole behind the thermostat
may in certain cases need to be sealed to prevent erroneous
temperature measurement. Position the thermostat back
plate against the wall so that it appears level and so the
thermostat wires protrude through the middle of the back
plate. Mark the position of the back plate mounting holes
and drill holes with a 3/16" (5mm) bit. Install supplied
anchors and secure plate to the wall. Thermostat wire must
be 18 AWG wire. Wire the appropriate thermostat as shown
in Figures 24a and 24b to the low voltage terminal strip
on the DXM2 control board. Practically any heat pump
thermostat will work with these units, provided it has the
correct number of heating and cooling stages. However,
using the communicating thermostat (ATC32) is highly
recommended for on-site, easier confi guration, monitoring
and diagnosis.
CAUTION!
CAUTION! Refrigerant pressure activated water regulating
valves should never be used.
CAUTION!
CAUTION! If communicating thermostat is not installed, a
communicating service tool must be used to confi gure and
diagnose this system.
Figure 27: Communication Flow
Communicating
Thermostat
Or
Diagnostic
Tool
Or
Mot.
Modulating
Valve
Fan
Sensors
Two-Way Communication
One-Way Communication
Variable
Speed
Pump
Electrical - Thermostat Wiring
Figure 28a: Communicating Thermostat Connection to
DXM2 Control
iGate™ Thermostat
ATC32U**
C
24Vac Common Comm +
R
Comm -
24Vac Hot
Figure 28b: Conventional 3 Heat / 2 Cool Thermostat
Connection to DXM2 Control
Thermostat
Y1
Compressor
Y2
Compressor Stage 2
W
Auxiliary Heat
DH
Dehumidification
O
Reversing Valve
G
Fan
R
24Vac Hot
C
24Vac Common
L
Fault LED
Notes:
1) ECM automatic dehumidification mode operates with dehumidification airflows
in the cooling mode when the dehumidification output from thermostat is active.
Normal heating and cooling airflows are not affected.
2) DXM2 board DIP switch S2-7 must be in the auto dehumidification mode for
automatic dehumidification
3) DH connection not possible with units with internal pump. Use ATC32U**.
4) Only use ATC Communicating Thermostat when using Humidifier (H Input) with
units with internal flow controller.
Auxiliary Heat Installation
In both vertical and horizontal confi gurations, auxiliary electric
heater is installed externally to the unit.
For installation instructions, refer to the Electric Heat IOM,
97B0005N03.
Typical Vertical External Mount Installation
Electric Heat Assembly
Air Coil
R e v : 4 A p r i l , 1 4
DXM2
Gnd
A+
A+
B-
B-
24V
OD Outdoor
Sensor
(Optiona)
GND
Remote Indoor
ID
Sensor
(Optiona)
DXM2
Board
Y1
Y2
W
H
O
G
R
C
AL1
Auxiliary electric heat
power supply knockout
opposite air coil
* Low Voltage control harness
is prewired on all distributor
class units.
®
29