Service manual

28
Geothermal Heat Pump Systems
Tranquility
®
22 Digital (TZ) Series IOM - 60Hz HFC-410A
Rev.: 17 Jan., 2013B
Electrical - Thermostat Wiring and Auxiliary Heat
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,
97B0005N02.
Auxiliary electric heat
power supply knockout
opposite air coil
Electric Heat Assembly
Air Coil
*Low Voltage control
harness is prewired on
all distributor class units.
Transition bracket between
cabinet top and electric
heater shipped with
TZ036 and 042.
Typical Vertical External Mount Installation
Thermostat
Compressor
Compressor Stage 2
Reversing Valve
Fan
24Vac Hot
24Vac Common
Fault LED
DXM2
Board
Y1
Y2
W
H
O
G
R
C
AL1
Y1
Y2
W
DH
O
G
R
C
L
Dehumidification
Notes:
Auxiliary Heat
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.
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 due to air infi ltration through the
wall cavity. 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 or larger wire.
Wire the appropriate thermostat as shown in Figures 26a and
26b 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 (ATC32U**) is highly recommended for on-site,
easier confi guration, monitoring and diagnosis.
Figure 26a: iGate™ Communicating Thermostat
Connection to DXM2 Control
ATC32U** Thermostat
24Vac Hot
DXM2
24V
Comm +
A+
A+
Comm -
B-
B-
OD
ID
GND
Outdoor
Sensor
(Optiona)
Remote Indoor
Sensor
(Optiona)
24Vac Common
Gnd
R
C
Figure 26b: Conventional 3 Heat / 2 Cool Thermostat
Connection to DXM2 Control
Communicating
Thermostat
Mot.
Modulating
Valve
Fan
Variable
Speed
Pump
Two-Way Communication
One-Way Communication
Sensors
Diagnostic
Tool
Or
Or
 CAUTION! 
 CAUTION! 
CAUTION! Refrigerant pressure activated water regulating
valves should never be used with ClimateMaster
equipment.
CAUTION! If communicating thermostat is not installed, a
communicating service tool must be used to confi gure and
diagnose this system.