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C-Blower Compartment
The blower compartment in all LHT092/150H units is locat
ed between the indoor coil and the outdoor coil section. The
blower assembly is accessed by disconnecting the blower
motor and all other plugs and removing the screws in front
of the blower housing.
1-Blower Wheels
Units are equipped with a backward inclined blower wheel.
See "SPECIFICATIONS" at the front this manual for more
detail.
2-Indoor Blower Motor B3
Units are equipped with a direct drive blower assembly with
a three-phase, variable speed, direct drive blower motor.
All motor specifications are listed in the SPECIFICATIONS
(table of contents) in the front of this manual. Units may be
equipped with motors manufactured by various manufac
turers, therefore electrical FLA and LRA specifications will
vary. See unit name plate for information specific to your
unit.
A-Blower Operation
Refer to the Unit Controller Setup Guide to energize blow
er. Use the mobile service app menu; see SERVICE >
TEST.
In both thermostat and zone control mode, the Unit Con
troller will stage the blower between low and high speed.
WARNING
1-Make sure that unit is installed in accordance with the
installation instructions and applicable codes.
2-Inspect all electrical wiring, both field‐ and factory‐
installed, for loose connections. Tighten as required.
3-Check to ensure that refrigerant lines do not rub against
the cabinet or against other refrigerant lines.
4-Check voltage at disconnect switch. Voltage must be
within range listed on nameplate. If not, consult power
company and have voltage condition corrected before
starting unit.
5-Make sure filters are new and in place before start‐up.
Initiate blower only (G) demand at thermostat according to
instructions provided with thermostat. Unit will cycle on
thermostat demand. The following steps apply to applica
tions using a typical electro-mechanical thermostat.
1- Blower operation is manually set at the thermostat sub
base fan switch. With fan switch in ON position, blow
ers will operate continuously.
2- With fan switch in AUTO position, the blowers will cycle
with demand. Blowers and entire unit will be off when
system switch is in OFF position.
NOTE - Blower operation mode can also be initiated by the
mobile service app.
Direct-drive motor may not immediately stop when power is
interrupted to the Unit Controller. Disconnect unit power
before opening the blower compartment. The Controller's
digital inputs must be used to shut down the blower. See
Unit Controller manual for operation sequences.
B-Blower Access
The blower assembly is secured to a sliding frame which
allows the blower assembly to be pulled out of the unit. See
figure 8.
1- Loosen the reusable wire tie which secures the con
trols and high voltage blower wiring to the blower hous
ing. Disconnect the pressure sensor low voltage wire
harness.
2- Remove and retain screws on either side (and on the
front for direct drive) of sliding frame. Use the metal
handle to pull frame toward outside of unit.
3- Slide frame back into original position when finished
servicing. Reattach the blower wiring in the previous lo
cation using the wire tie. Reconnect pressure sensor
low voltage wire harness.
4- Replace retained screws.
The supply CFM can be adjusted by changing the percent
age of motor output using the Unit Controller settings Refer
to table 1 for menu paths and default settings. Record any
RPM% changes on the parameter settings label located on
the inside of the compressor access panel.
CAUTION
The BLOWER CALIBRATION process starts the indoor
blower at operational speeds and moves the economizer
damper blades. Before starting this process, replace any
access panels and close all unit doors except com
pressor compartment door.
Blower calibration is required only on units that are newly
installed or if there is a change in the duct work or air filters
after installation. Use the mobile service app to navigate to
the SETUP>TEST & BALANCE>BLOWER menu. After
the new CFM values are entered, select START CALIBRA
TION. The blower calibration status is displayed as a %
complete. Upon successful completion, the mobile service
app will display CALIBRATION SUCCESS and go back to
the blower calibration screen.
IMPORTANT - The default value for Cooling Low CFM is
lower than a traditional singe- or two-speed unit. If operat
ing the unit with a 2- or 3-stage controller (2- or 3-stage
thermostat, DDC controller, etc.), it is recommended to in
crease the Cooling Low CFM default value to a suitable lev
el for part load cooling (typically 60% of full load CFM).
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