Warning, Startup and checkout – Nordyne R-410A User Manual
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Wire Size based on N.E.C. for 60° type copper con-
ductors.
COPPER WIRE SIZE — AWG
(1% Voltage Drop)
Supply Wire Length-Feet
Supply Circuit
200
150
100
50
Ampacity
6
8
10
14
15
4
6
8
12
20
4
6
8
10
25
4
4
6
10
30
3
4
6
8
35
3
4
6
8
40
2
3
4
6
45
2
3
4
6
50
Wiring Diagram/Schematic — A wiring 
diagram/schematic is located on the inside cover 
of the electrical box of the outdoor unit. The 
installer should become familiar with the wiring 
diagram/schematic before making any electrical 
connections to the outdoor unit.
Outdoor Unit Connections — The outdoor 
unit requires both power and control circuit 
electrical connections. Refer to the unit wiring 
diagram/schematic for identifi cation and location 
of outdoor unit fi eld wiring interfaces.
Control Circuit Wiring — The outdoor unit is 
designed to operate from a 24 VAC Class II control 
circuit. Control circuit wiring must comply with 
the current provisions of the “National Electrical 
Code” (ANSI/NFPA 70) and with applicable local 
codes having jurisdiction.
Thermostat connections should be made in 
accordance with the instructions supplied with 
the thermostat, and with the instructions supplied 
with the indoor equipment. A typical residential 
installation with a heat pump thermostat and air 
handler are shown below. 
Electrical Power Wiring — Electrical power 
wiring must comply with the current provisions 
of the “National Electrical Code” (ANSI/NFPA 
70) and with applicable local codes having 
jurisdiction. Use of rain tight conduit is 
recommended. Electrical conductors shall have 
minimum circuit ampacity in compliance with the 
outdoor unit rating label. The facility shall employ 
electrical circuit protection at a current rating no 
greater than that indicated on the outdoor unit 
rating label. Refer to the unit wiring diagram for 
connection details.
Minimum Circuit Ampacity — Electrical wiring 
to the equipment must be compatible and in 
compliance with the minimum circuit ampacity 
listed on the outdoor unit data label.
Maximum Fuse/Circuit Breaker Size — Circuit 
protection for the outdoor unit must be compatible 
with the maximum fuse/circuit breaker size listed 
on the outdoor unit data label. 
Disconnect Switch — An electrically compatible 
disconnect switch must be within line of sight of 
the outdoor unit. This switch shall be capable of 
electrically de-energizing the outdoor unit.
Optional Equipment — Optional equipment 
requiring connection to the power or control 
circuits must be wired in strict accordance with 
current provisions of the “National Electrical 
Code” (ANSI/NFPA 70), with applicable local 
codes having jurisdiction, and the installation 
instructions provided with the equipment. 
Optional Equipment (e.g.: liquid line solenoid 
valves, hard start kits, low suction pressure 
cutout switch kit, high pressure cutout switch kit, 
refrigerant compressor crankcase heater, etc.) 
should be installed in strict accordance with the 
manufacturer’s installation instructions. 
STARTUP AND CHECKOUT
WARNING:
Ensure electrical power to the unit is 
off prior to performing the following 
steps. Failure to do so may cause 
personal injury or death.
Air Filters — Ensure air fi lters are clean and in 
place prior to operating the equipment. 
Thermostat — Set the room thermostat function 
switch to OFF, fan switch to AUTO, and adjust the 
temperature setpoint to its highest setting.
Prior to applying electrical power to the outdoor 
unit, ensure that the unit has been properly and 
securely grounded, and that power supply 
connections have been made at both the facility 
power interface and outdoor unit.
Outdoor Unit — Ensure the outdoor coil and 
top of the unit are free from obstructions and 
debris, and all equipment access/control panels 
are in place.
Using extreme caution, apply power to the unit 
and inspect the wiring for evidence of open, 
shorted, and/or improperly wired circuits.
