Electrical - High Voltage
|
11
Revised 08/14
8 733 914 818 (2014/08)
SV Heat Pump Series
ELECTRICAL - HIGH VOLTAGE
All field installed wiring must comply with the
National Electric Code as well as all applicable
local codes. Refer to the unit electrical data on the
unit name plate for wire and branch circuit
protection sizing. Supply power voltage and
phasing should match the required voltage and
phasing shown on the unit name plate. Operating
the unit below the minimum voltage, above the
maximum voltage or with incorrect phasing can
result in poor system performance or damage to
the heat pump. All field wiring should be installed
by qualified and trained personnel. Refer to the
unit wiring diagram for field connection
requirements.
Power wiring to the heat pump should be enclosed
in flexible conduit to minimize the transmission of
vibration from the unit cabinet to the building.
For heat pumps with unit mounted disconnect
switches, field power should be connected to the
marked terminals on the disconnect switch. For
heat pumps without unit mounted disconnect
switches (except for 460 volt units noted below
and units with dual power supply), power is
connected to the line (L) side of the compressor
contactor and the ground lug in the unit electrical
box.
Models with Dual Power Supplies
For models with dual power supplies, one power
supply feeds the compressor and a second power
supply feeds the unit fan motor and control circuit.
The compressor power supply should be
connected to the line (L) side of the compressor
contactor. The fan motor and control circuit
power supply should be connected to a provided
terminal block. Care should be taken to insure that
each power supply meets the voltage, amperage
and phase requirements of its load. Refer to the
unit nameplates for requirements.
460 V Models with Constant Air Flow
Motors (SV015-SV070)
460 volt SV heat pumps with the constant airflow
motor option require a properly sized neutral wire
with the power supply wiring in addition to the
three high voltage wires and the ground wire.
These units employ a 265 V motor that requires
power from one phase of the 460 V supply and the
neutral wire.
For 460 V models with constant air flow motors
and a unit mounted disconnect switch, the power
wires and neutral wire should be connected to the
appropriate terminals on the disconnect switch
and its enclosure. For units without a disconnect
switch, power and neutral wires should be
connected to a provided 4 pole terminal block in
the unit electrical box
Transformer Settings for 208/230 V Units
As factory built, all 208/230 V units are wired for
230 V operation. For job sites with a 208 V power
supply, the primary leads on the unit transformer
will need to be changed from 240 V to 208 V. Refer
to the unit wiring diagram for details.
ELECTRICAL - LOW VOLTAGE
For heat pumps with PSC or constant torque fan
motors, all thermostat wiring is connected to a
terminal block located in the unit electrical box.
For heat pumps with a constant air flow fan motor,
thermostat wiring is connected to a removable
terminal strip located on the ECM motor control
board located in the electrical box. Refer to the
unit wiring diagram for connection details.
Unless provided with DDC controls, the SV heat
pump can be controlled by most commonly
available single stage heat pump thermostats.
Note that the reversing valve on the SV series is
energized when the unit is in the cooling mode.
Thermostats should be located on an interior wall
away from supply ducts. Avoid locations subject to
direct sunlight or drafts, or external walls.
Thermostat wiring should be 18 AWG. Refer to the
installation instructions for the thermostat for
further details.
SV heat pumps are supplied with a 75 VA control
transformer as standard. The VA capacity of the
transformer should be considered when
connecting low voltage accessories to the heat
pump such as thermostats or solenoid valves.
NOTE:
All power connections must be
properly torque to avoid the risk of
overheating.
WARNING:
The power supply ground wire
should never be used as a neutral wire.
WARNING:
Never route control wiring
through the same conduit as power supply
wiring.
Exceptionally long runs of thermostat wire
should be avoided to prevent voltage drops in
the control circuit.
