Blower Operation And Adjustments - Lennox LCH Series Installation Instructions Manual

Wire runs over 150 feet (mm):
Use a local, isolated 24VAC transformer such as
Lennox cat #18M13 (20VA minimum) to supply power
to RH sensor as shown in figure 17. Use two shielded
cables containing 20AWG minimum, twisted pair
conductors with overall shield. Belden type 8762 or
88760 (plenum) or equivalent.
FIELD WIRING REHEAT UNITS
(Using A Humidity Sensor With
More than 150 Ft. Wire Runs)
NOT
CONNECTED
ISOLATED 24V
TRANSFORMER
A91 DRAIN
VIN
NOT
CONNECTED
GND
VO
FIGURE 17
FIELD WIRING REHEAT UNITS
(Using A Dehumidification Switch)
DEHUMIDIFICATION
SWITCH
Use 24 VAC (R) from any terminal
available on J299−2, −5, or −7.
FIGURE 18
LGH/LCH036, 048, 060, 072, 074
A55 UNIT
CONTROLLER
P298
J298A
R
1
2 C
B
3 AI-1
4
C
5 HUM
6
TMP
7
D
8
DO-1
9
C
10
DO-2
DI-1
J299
7 R
8 DI−4
C
9
10

Blower Operation and Adjustments

Units are equipped with one of three factory-installed
blower options. The ninth character in the model number
identifies the blower as follows:
E= High efficiency three-, four- and five-ton units are
equipped with a variable speed, direct drive blower.
When these units are also equipped with an
economizer and configured for Advanced Air Flow
Control, the installer is able to enter the
design-specified supply and outdoor air CFM into
the Unit Controller. This eliminates the need to
manually take measurements and adjust settings.
See Advanced Air Flow Control Start-Up section.
Ultra high efficiency units are also equipped with a
variable speed, direct drive blower. The installer is
able to enter the design-specified supply air CFM
into the Unit Controller for optimal efficiency. The
Unit Controller calibrates the supply air volume
which eliminates the need to manually take duct
static measurements. Refer to D-Adjusting Unit
CFM - Ultra High Efficiency Direct Drive Blowers.
T= Units are equipped with a two-stage belt drive blower.
B= Units are equipped with a single-stage belt drive
blower.
Note - Six-ton, non-ultra high efficiency units are
available with belt drive blowers only.
Three phase scroll compressors must be phased
sequentially for correct compressor and blower
rotation. Follow "COOLING START-UP" section of
installation instructions to ensure proper compres­
sor and blower operation.
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IMPORTANT