Refrigeration System; Blower Speed & Belt Tension - Lennox ELA Series Unit Information

TERMINAL STRIP
(TB1)
K220 RELAY
(FIELD INSTALLED)
CONTROL
PANEL
II − REFRIGERATION SYSTEM
Units are equipped with single refrigerant circuit (072) or dual refrigerant circuit (090−240). The 090−240 units have a dual
distribution system for two stage capacity control during cooling cycles. Each circuit has its own service valve connection
and expansion valve.
III − BLOWER SPEED & BELT TENSION
Air Volume Adjustment
FIXED PULLEY
BLOWER BELT
ADJUSTABLE
PULLEY
BLOWER RELAY
(K43)
MSAV RELAY
(K232)
FIGURE 2. Unit Control Box Arrangement
GROUND LUG
TERMINAL BLOCK
(TB13)
MSAV CONTROL BOARD
INVERTER
1
Run the blower without a cooling demand.
2
Measure the static pressure external to the unit.
3
Measure the indoor blower motor's rpm.
Use the static pressure and rev/min readings to
4
determine the unit's air volume (see applicable blower
performance tables).
5 Loosen the Allen screw on the adjustable pulley.
Turn the adjustable sheave clockwise to increase the air
6
volume or counterclockwise to decrease the air volume.
Once the desired air volume has been achieved, tighten
7
the Allen screw.
NOTE − The indoor coil must be dry and the air
filters must be in place when the following
measurements are taken.
ADJUSTABLE PULLEY
ALLEN SCREW
FIGURE 3
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