Service Light Thermostat; Dual Capacitor; Defrost Thermostat/Timer; Reversing Valve And Solenoid - Lennox HP22-261 Service Manual

OUTDOOR FAN, BRACKET AND
TEMPERATURE COMPENSATION
FIGURE 8
I-Service Light Thermostat
All units are equipped with a service light thermostat
mounted on the compressor discharge line. The switch
is electrically connected to the service light in the indoor
thermostat. The switch is closed on compressor startup
and the thermostat service light is momentarily lighted.
When compressor discharge line temperature reaches
130+5_F, the thermostat opens and the service light
goes off.
If discharge line temperature drops below 110+5_F dur
ing unit operation, (indicating a problem in the system),
the thermostat closes and the service light is powered to
indicate service is needed.
J-Dual Capacitor
The compressor and fan in HP22-261,-311,-411 and
-461 series units use permanent split capacitor motors.
A single dual" capacitor is used for both the fan motor
and the compressor (see unit wiring diagram). The fan
side of the capacitor and the compressor side of the ca
pacitor have different mfd ratings. The capacitor is lo
cated inside the unit control box (see figure 5). Table 2
shows the ratings of the dual capacitor.
THERMISTOR
OUTDOOR FAN
FAN MOTOR
BRACKET
THERMISTOR
HP22 DUAL CAPACITOR RATING
Units Terminal
HP22-261
HP22-311
HP22-411
HP22-461
K-Defrost Thermostat
A defrost thermostat is mounted on the liquid line be
tween the filter/drier and the distributor. The thermostat
opens at 70+5_F and closes at 35+5_F. For defrost to
begin, the defrost thermostat must be closed when the
defrost timer calls for defrost.
L-Reversing Valve and Solenoid
A refrigerant reversing valve with electromechanical sole
noid is used to reverse refrigerant flow during unit opera
tion. The reversing valve is energized during cooling de
mand and during defrost. Refer to figures 14 and 15 for
more information.
M-Defrost Timer
The CMC defrost control (figure 9) is a solid state control
manufactured by Hamilton Standard. The control pro
vides automatic switching from normal heating operation
to defrost mode and back. The control provides 14 min
ute defrost periods at 30, 60 or 90 minute field change
able intervals. The control monitors thermostat demand
and holds the timer in place between thermostat de
mand. A set of diagnostic pins are also provided for trou
bleshooting the unit.
Page 6
TABLE 2
MFD
FAN 5
HERM 30
FAN 5
HERM 35
FAN 5
HERM 35
FAN 5
HERM 35
VAC
370
440