Lennox LCH036 Installation Instructions Manual page 12

FIELD WIRING REHEAT UNITS (Using A Humidity
Sensor With Less Than 150 Ft. Wire Runs)
J298A
1
A91
2
B
VIN
3
4
C
2
VO 5
6
7
GND
D
8
9
10
FIGURE 16
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)
J299
DEHUMIDIFICATION
SWITCH
Use 24 VAC (R) from any terminal
available on J299−2, −5, or −7.
FIGURE 18
P298
R
10
C
11
AI−1
12
HUM
TMP
DO−1
C
5
DO−2
6
DI−1
A55 UNIT
CONTROLLER
P298
J298A
R
1
2 C
B
AI-1
3
4
C
HUM
5
6
TMP
7
D
8
DO-1
9
C
10 DO-2
DI-1
R
7
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= 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.
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 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.
A-Blower Operation
Refer to the Unit Controller Installation and Setup Guide
to energize blower. Use the menu navigation arrows and
select button; see SERVICE > TEST.
B-Determining Unit CFM
1- The following measurements must be made with air
filters in place.
IMPORTANT - On units equipped with direct drive
blowers, a low speed adjustment less than 2/3 of high
speed will improve humidity removal; refer to product
data for more information.
2- With all access panels in place, measure static
pressure external to unit (from supply to return).
Blower performance data is based on static pressure
readings taken in locations shown in figure 19.
Note - Static pressure readings can vary if not taken
where shown.
3- Measure the indoor blower wheel RPM.
4- Referring to Page 16 through Page 26, use static
pressure and RPM readings to determine unit CFM.
Use Page 27 when installing units with any of the
options or accessories listed. Refer to table 4 for
minimum airflow when electric heat is installed.
Page 12
IMPORTANT
LGH/LCH036, 048, 060, 072