Electrical Requirements - Nordyne S3BM-120G User's Information And Installation Instructions Manual

ELECTRICAL REQUIREMENTS

CAUTION:
Shut off all electrical power to the unit before
performing any maintenance or service on the
system. Failure to comply may result in personal
injury or death.
Pre-Electrical Checklist
√ Verify that the voltage, frequency and phase of the
supply source are the same as those specifi ed on the
unit rating plate.
√ Verify that the service provided by the utility is
suffi cient to handle the additional load imposed by this
equipment.
√ For minimum circuit ampacity and maximum overcurrent
protection, see the unit rating plate.
Wiring Diagram/Schematic
A wiring diagram/schematic is located on page 11 of this
manual and on the inside cover of the electrical box of
the outdoor unit.
IMPORTANT NOTE: The installer should become
familiar with the wiring diagram/schematic before
making any electrical connections to the outdoor
unit.
Supply Control Circuit Wiring
• The outdoor unit is equipped with a 24 VAC Class ll
transformer for low voltage circuit control. All wiring
must comply with applicable local codes having
jurisdiction.
• Units are shipped factory wired for 380 volt operation.
See unit data label for proper incoming fi eld wiring.
• When using two air handlers, refer to twinning
instructions (707973) for proper low voltage control
wiring.
COPPER WIRE SIZE - AWG
(1% Voltage Drop)
Supply Wire Length - Feet
200 150 100
6 8 10
4 6 8
4 6 8
4 4 6
3 4 6
3 4 6
2 3 4
2 3 4
2 3 4
1 2 3
NOTE: Wire size based on N.E.C. for 60° type copper conductors.
Table 1. Copper Wire Size
6
Supply Circuit
Ampacity
50
14 15
12 20
10 25
10 30
8 35
8 40
6 45
6 50
6 55
4 60
Line Voltage
• Electrical power wiring must be made in accordance
with all applicable local codes and ordinances.
• Provide power supply for the unit in accordance with
the unit wiring diagram, and the unit rating plate.
• Connect the line-voltage leads to the terminals on the
contactor inside the control compartment.
• Use only copper wire for the line voltage power supply
to this unit. Use proper code agency listed conduit and
a conduit connector for connecting the supply wires to
the unit.
CAUTION:
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation. Verify proper
operation after servicing.
• If any of the original wire as supplied with the unit must
be replaced, it must be replaced with material of the
same gauge and temperature rating.
• See the unit wiring label for proper high and low voltage
wiring. Make all electrical connections in accordance
with all applicable codes and ordinances.
• Use a separate branch electrical circuit for this unit. A
means of electrical disconnect must be located within
sight of and readily accessible to the unit.
• Overcurrent protection must be provided at the branch
circuit distribution panel and sized as shown on the unit
rating label and according to applicable local codes.
Outdoor Unit Connections
The outdoor unit requires both power and control circuit
electrical connections. Refer to the wiring diagram (Figure
3, page 11) for identifi cation and location of outdoor unit
fi eld wiring interfaces.
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 applicable local codes having jurisdiction, and the
installation instructions provided with the equipment.
• Optional Equipment (e.g.: liquid line solenoid valves,
twinning kit, low ambient, etc.) should be installed in
strict accordance with the manufacturer's installation
instructions.
Thermostat Connections
Thermostat connections should be made in accordance
with the instructions supplied with the thermostat, and with
the instructions supplied with the indoor equipment.