Lennox SSB*H4 Manual page 10

C − Condenser Fan Motor
All units use single−phase PSC fan motors which require a run
capacitor. In all units, the condenser fan is controlled by
the compressor contactor.
ELECTRICAL DATA tables in this manual show specifi-
cations for condenser fans used in SSB*H4's.
Access to the condenser fan motor on all units is gained
by removing the four screws securing the fan assembly.
See figure 4. The grill fan assembly can be removed from
the cabinet as one piece. See figure 5. The condenser fan
motor is removed from the fan guard by removing the four
nuts found on top of the grill. See figure 5 if condenser fan
motor replacement is necessary.
DANGER
Make sure all power is disconnected before
beginning electrical service procedures.
Remove
screws
Remove
screws
FIGURE 4
ALIGN FAN HUB FLUSH WITH END OF SHAFT
FIGURE 5
IMPORTANT
Pressure switch settings for R−410A refrigerant
will be significantly higher than units with R−22.
D − Low Pressure Switch
An auto-reset, single-pole/single-throw low pressure switch
is located in the suction line. This switch shuts off the com-
pressor when suction pressure drops below the factory set-
ting. The switch is closed during normal operating pressure
conditions and is permanently adjusted to trip (open) at 40 +
5 psi. The switch automatically resets when suction line
pressure rises above 90 + 5 psi. Under certain conditions the
low pressure switch is ignored.
E − High Pressure Switch
A manual-reset, single-pole/single-throw low pressure
switch is located in the liquid line. The switch is closed dur-
ing normal operating pressure conditions. The switch re-
moves power from the compressor contactor control circuit
when discharge pressure rises above factory setting at 590
+ 10 psi.
F − Crankcase Heater (HR1) &
Thermostat (S40)
Some units are equipped with a 70 watt, belly band type
crankcase heater. HR1 prevents liquid from accumulating in
the compressor. HR1 is controlled by a thermostat located on
the liquid line. When liquid line temperature drops below 50°
F the thermostat closes energizing HR1. The thermostat will
open, de−energizing HR1 once liquid line temperature reach-
es 70° F .
G − Crankcase Heater Relay K191 (G Voltage)
All 460 volt SSB units require the S40 thermostat to be wired
in series with the 24 volt coil of the K191 relay. The contacts
of the K191 control operation of crankcase heater HR1.
When ambient temperature drops below 50° F, K191 con-
tacts close energizing HR1. When the ambient temperature
rises to 70° F the contacts open de−energizing HR1.
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