Nordyne T4BD-042 Series, Installation Instructions Manual

Page: 6 / 20

6
G R
W2
C
E
O Y
Thermostat
Green
Red
White
G
R
Black
O
Y1 IN
R
C
Air Handler
Heat Pump
(OD Section)
C
W
W2 OUT
W2 IN
Figure 4. Typical Thermostat Connections
Thermostat / Low Voltage Connections
• Thermostat connections should be made in accordance
with the instructions supplied with the thermostat and
the indoor equipment. A typical installation with a heat
pump thermostat and air handler is shown in
Figure 4 .
• The outdoor unit is designed to operate from a 24 VAC
Class II control circuit. The control circuit wiring must
comply with the current provisions of the NEC (ANSI/
NFPA 70) and with applicable local codes having
jurisdiction.
• The low voltage wires must be properly connected to
the units low voltage terminal block. Recommended
wire gauge and wire lengths for typical thermostat
connections are listed in
Table 2 .
• The thermostat should be mounted about 5 feet
above the floor on an inside wall. DO NOT install the
thermostat on an outside wall or any other location
where its operation may be adversely affected by radiant
heat from fireplaces, sunlight, or lighting fixtures, and
convective heat from warm air registers or electrical
appliances. Refer to the thermostat manufacturer’s
instruction sheet for detailed mounting and installation
information.
CoreSense
TM
Diagnostics Module
(Select Models Only)
The CoreSense
TM
Diagnostics Module ( Figure 5, (page
7) ) is a breakthrough innovation for troubleshooting
heat pump and air conditioning system failures. The module
installs easily in the electrical box of the outdoor unit
near the compressor contactor.By using the compressor
as a sensor, CoreSense Diagnostics helps the service
technician more accurately troubleshoot system and
compressor fault conditions.
A flashing LED indicator communicates the ALERT code
and a diagnostic key is also imprinted on the side of the
module to quickly direct the technician to the root cause
of a problem.
Alert identification codes are also listed in
Table 3, (page 8) .
• Optional equipment requiring connection to the power
or control circuits must be wired in strict accordance
of the NEC (ANSI/NFPA 70), applicable local codes,
and the instructions provided with the equipment.
Grounding
WARNING:
The unit cabinet must have an uninterrupted or
unbroken electrical ground to minimize personal
injury if an electrical fault should occur. Do not
use gas piping as an electrical ground!
This unit must be electrically grounded in accordance
with local codes or, in the absence of local codes, with
the National Electrical Code (ANSI/NFPA 70) or the CSA
C22.1 Electrical Code. Use the grounding lug provided in
the control box for grounding the unit.
Table 2. Thermostat Wire
THERMOSTAT
WIRE GAUGE
MAXIMUM RECOMMENDED
THERMOSTAT WIRE LENGTH (FT)
24 25
22 45
20 70
18 110