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C-Blower Compartment
NOTE - Units equipped a Variable Frequency Drive (VFD)
are designed to operate on balanced, three-phase power.
Operating units on unbalanced three-phase power will re-
duce the reliability of all electrical components in the unit.
Unbalanced power is a result of the power delivery system
supplied by the local utility company. Factory-installed in-
verters are sized to drive blower motors with an equiva-
lent current rating using balanced three-phase power. If
unbalanced three-phase power is supplied; the installer
must replace the existing factory-installed inverter with an
inverter that has a higher current rating to allow for the im-
balance. Refer to the installation instructions for additional
information and available replacements.
The blower compartment in all units is located between
the evaporator coil and the condenser coil section. The
blower assembly is accessed by disconnecting the blower
motor .See Blower Access in the Operation/ Adjustment
section.
1-Blower Wheels
blower wheel.
2-Indoor Blower Motor B3
All units use three-phase single-speed blower motors.
manual. Units may be equipped with motors manufactured
Operation and Adjustments
A-Three Scroll Compressor Voltage Phasing
Three phase scroll compressors must be phased
sequentially to ensure correct compressor and blower
rotation and operation. Compressor and blower are wired
in phase at the factory. Power wires are color-coded as
1 - Observe suction and discharge pressures and
blower rotation on unit start-up.
is not correct:
2 -
marking.
3 - Disconnect all remote electrical power supplies.
4 -
at blower contactor or compressors.
Make sure the connections are tight.
Discharge and suction pressures should operate at their
normal start-up ranges.
Supply Air Inverter Units - Units are equipped with a
phase monitor located in the control compartment. The
phase monitor will detect the phasing of incoming power.
If the incoming power is out of phase or if any of the three
will turn red and the unit will not start. In normal operation
green.
B-Blower Operation
Initiate blower demand at thermostat according to
instructions provided with thermostat. Unit will cycle
on thermostat demand. The following steps apply to
applications using a typical electro-mechanical thermostat.
1 - Blower operation is manually set at the thermostat
ON
blowers will operate continuously.
2 - AUTO
cycle with demand. Blowers and entire unit will be
OFF position.
C-Blower Access
The blower assembly is secured to a sliding frame which
allows the blower motor to be pulled out of the unit. See
1 - Loosen the reusable wire tie which secures the
blower wiring to the blower motor mounting plate.
2 -
frame. Pull frame toward outside of unit.
3 -
location on the blower motor base using the wire tie.
4 -
frame.
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