Lennox LGH240H

Page 38
LOCATION OF STATIC PRESSURE READINGS
SUPPLY AIR
READING
LOCATION
SUPPLY
TURN
INSTALLATIONS WITH DUCTWORK
SUPPLY
TURN
INSTALLATIONS WITH CEILING DIFFUSERS
MAIN
DUCT RUN
FIRST BRANCH
OFF OF MAIN RUN
DIFFUSER
ROOFTOP UNIT
ROOFTOP UNIT
SUPPLY AIR
READING
LOCATION
RETURN AIR
READING LOCATION
RETURN AIR
READING
LOCATION
FIGURE 11
1 - The following measurements must be made with a
dry indoor coil. Run blower without cooling demand.

taken.
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

Note - Static pressure readings can vary if not taken
where shown.
3 - Measure the indoor blower wheel RPM.
4 - Refer to blower tables in BLOWER DATA (table
of contents) in the front of this manual. Use static
pressure and RPM readings to determine unit air
volume.
5 - The RPM can be adjusted at the motor pulley.
Loosen Allen screw and turn adjustable pulley
clockwise to increase RPM. Turn counterclockwise

Blower Belt Adjustment
Maximum life and wear can be obtained from belts only if
proper pulley alignment and belt tension are maintained.
Tension new belts after a 24-48 hour period of operation.
This will allow belt to stretch and seat into pulley grooves.
Make sure blower and motor pulley are aligned as shown
         
equipped with an optional belt tensioner.
Standard Blowers
1 - Loosen four screws securing blower motor to sliding

2 - To increase belt tension - Turn belt tension
adjusting screw to the left, or counterclockwise,
to tighten the belt. This increases the distance
between the blower motor and the blower housing.
To loosen belt tension - Turn the adjusting screw to
the right, or clockwise to loosen belt tension.
3 - Tighten four screws securing blower motor to sliding
base once adjustments have been made
PULLEY ALIGNMENT - NO TENSIONER
BELT
BLOWER
PULLEY
MOTOR
PULLEY
NOT ALIGNED
ALIGNED
FIGURE 12
BELT
BLOWER
PULLEY
MOTOR
PULLEY
NOT ALIGNED
ALIGNED
TENSIONER
PULLEY ALIGNMENT - WITH TENSIONER
FIGURE 13
Blowers Equipped With Belt Tensioner
1 - Loosen the bolt in the center of the tensioner. See

2 - Place belt over all three pulleys.
3 - Using a 15/16” wrench, turn the tensioner nut until

4 - Hold the tensioner with marks aligned and tighten
