Lennox CHA16 User Manual

Page 25
When discharge pressure drops below 25+5 psig (indicat
ing a loss of charge in the system) the switch opens and
the compressor is de-energized. The switch automatically
resets when refrigerant is added and pressure in the dis
charge line rises above 55+
5 psig.
5-Thermometer Well (Figure 22)
All units are factory equipped with a thermometer well for
charging the unit. The well is used to accurately measure
the temperature of the liquid line. The temperature mea
sured is then used to calculate the approach or subcooling
temperature. Approach and subcooling temperatures are
compared to tables printed in the charging section of this
manual to determine the correct charge. Thermometer
wells are equipped with a gauge port for high pressure
gauge connection.
FIGURE 22
THERMOMETER WELL
THERMOMETER WELL
LIQUID LINE
GAUGE PORT
LIQUID LINE
To accurately measure the temperature of the liquid line,
the well should be filled with a light mineral oil before using.
This will ensure good heat transfer to the thermometer.
6-Freezestats S49, S50 and S53
Each evaporator is equipped with a low temperature limit lo
cated on a suction feeder. In three pump systems, S49 is lo
cated on the first stage compressor 1 coil, S50 is located on
the first stage compressor 2 coil and S53 is located on the
second stage coil. In two pump systems, S49 is located on
the first stage evaporator coil and S50 is located on the sec
ond stage evaporator coil.
Each freezestat is wired in series with its respective com
pressor contactor coil. Each freezestat is a SPST auto-re
set limit which opens at 29°F +
3°F on a temperature drop
and closes at 58°F + 4°F on a temperature rise. To prevent
coil icing, the freezestats open during compressor opera
tion to temporarily disable the respective compressor until
the coil warms sufficiently to melt any accumulated frost.
If the freezestats are tripping frequently due to coil icing,
check the unit charge, airflow and filters before allowing unit
back in operation. Make sure to eliminate all conditions
which might promote evaporator ice buildup.
7-Condenser Fans B4 and B5
The specifications tables on pages 2-6 in this manual
shows the specifications of condenser fans used in
CHA16 series units. Condenser outdoorfans in all
CHA16CHP16CHA16 units (all voltages) use three-phase
motors which do not require a run capacitor. CHA16823
and CHA16953 units are equipped with a single condens
er fan which operates during all compressor operation. All
other CHA16 units are equipped with two condenser fans.
In CHA161603 and CHA161853 units, both condenser
fans are energized upon receiving a first stage cooling de
mand. Condenser fans draw air across both condenser
coils during all compressor operation. In all other CHA16
series units, the condenser fans operate independently
and are staged with the compressors.
D-Blower Compartment/
Power MakeUp Components
1-Indoor Blower Motor B3
All CHA16 units use threephase singlespeed blower motors.
CFM adjustments are made by adjusting the motor pulley
(sheave). Blower motor ratings are shown in table 23. Motors
are equipped with sealed ball bearings. All motors and oper
ate at 1725 to 1760 RPM and all are internally overload pro
tected. Units may be equipped with motors manufactured by
Century, G.E., Emerson, Marathon or other manufacturer.
Electrical FLA and LRA specifications vary by manufacturer.
See unit rating plate for information specific to your unit.
Standard
TABLE 23
BLOWER MOTOR
Usage
Volts Phase
208/230
switchable to 460
3
3
HP
2
3
Electrical Characteristics
CHA16823Y,G
CHA16953-Y,G
CHA161353Y,G
Drive
Units
Standard
Optional
CHA16823J
CHA16953-J
CHA161353J
2 Standard 575
CHA161353Y,G
Standard
CHA161603Y,G
CHA161853Y,G
208/230
switchable to 460
3
3
Optional CHA161353J
Standard
CHA161603J
CHA161853J
3
575
5
Optional CHA161853Y,G
Standard CHA162553Y,G
208/230
switchable to 460
3
5
Optional CHA161853J
Standard CHA162553J
3575
7.5
Optional
CHA162553Y,G
CHA162753Y,G
CHA163003Y,G
208/230
switchable to 460
3
7.5
3575
Standard
Optional
CHA162553J
CHA162753J
CHA163003J
10 Optional CHA163003Y,G
208/230
switchable to 460
3
10 3575Optional CHA163003J

Lennox CHA16 Specifications

General

Brand	Lennox
Model	CHA16
Category	Air Conditioner
Language	English