Blower Operation And Adjustments; Determining Unit Cfm - Direct Drive Blowers; Blower Speed Factory Settings; Field-Adjustable Blower Speeds - Direct Drive 208/230V - Lennox KGB024 Installation Instructions Manual

Blower Operation and Adjustments

KG/KC 024 and 030 units are equipped with direct drive
blowers only. KG/KC 036, 048 and 060 units are equipped
with either direct drive or belt drive blowers. KG/KC 072,
074 and 090 units are available with belt drive blowers
only. KG/KC 074 units are equipped with two-stage
blowers. The blower will operate at high speed with a Y2
thermostat demand and low speed with a Y1 thermostat
demand. Low speed operation delivers approximately ⅔
of the air volume of high speed. Two-speed blower
operation results in lower energy consumption.
IMPORTANT
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
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
thermostat.
1- Blower operation is manually set at the thermostat
subbase fan switch. With fan switch in ON position,
blowers 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.
MEDIUM SPEED
024, 030, 036, 048 UNITS
L1-Terminal COM
L2-Terminal MED
1-COM
2-HI
3-MED
4-LOW
typical electro-mechanical

FIELD-ADJUSTABLE BLOWER SPEEDS - DIRECT DRIVE 208/230V

HIGH SPEED - ALL UNITS
TERMINAL 1
REMAINS AT
COMMON
1-COM
2-HI
3-MED
4-LOW
SPEED
TAPS
B-Determining Unit CFM - Direct Drive Blowers
1- The following measurements must be made with air
filters in place.
2- With all access panels in place, measure static
pressure external to unit (from supply to return). Add
any additional air resistance for options and
accessories shown in accessory air resistance tables.
Blower performance data is based on static pressure
readings taken in locations shown in figure 15.
Note - Static pressure readings can vary if not taken
where shown.
3- Use figure 16 to determine the factory set blower
speed.

BLOWER SPEED FACTORY SETTINGS

036 Units
1 Com
2 Hi
3 Med
4 Low*
4- Use direct drive blower tables, the measured static
pressure and the factory-set blower speed to
determine CFM. If CFM is lower or higher than the
design specified CFM, move the leads as shown in
figure 17 for 208/230 volt units and figure 18 for
460/575 volt units.
L1-Terminal COM
L2-Terminal HIGH
FIGURE 17
Page 11
024, 030, &
060 Units
048 Units
1 Com
2 Hi
3 Med*
4 Low
*Factory Setting
FIGURE 16
LOW SPEED
024, 030, 036, 048, UNITS
L1-Terminal COM
L2-Terminal LOW
1-COM
2-HI
3-MED
4-LOW
LOW SPEED
060 UNITS
L1-Terminal COM
L2-Terminal LOW
1-COM
2-HI
3-LOW
4-
507348-04
1 Com
2 Hi
3 Low*
4 Unused
12/2015