Evaporator Fan; Freezer And Fresh Food Light Thermostats - GE GBSC0 Technical Service Manual

Freezer and Fresh Food Light Thermostats

The freezer and fresh food light thermostats
interrupt power to the lights when the thermostat
temperature reaches 175°F. Power is restored when
the thermostat temperature cools to 155°F.
Each thermostat is attached to the back of each
light housing with an 11/32-in. nut.
To access the freezer light thermostat (models
GBSC0 and PFSF2), and fresh food light thermostat
(model PFSF2), it is necessary to remove the light
cover and light housing. The freezer light housing
is held in place by a single Phillips-head screw. The
fresh food light housing is held in place by 3 Phillips-
head screws.
Note: It is necessary to remove the freezer light bulb
to access the freezer light housing screw.
Fresh Food Light Housing (model PFSF2 shown)
To access the fresh food light thermostat on model
GBSC0, it is necessary to remove the control
housing. (See
Control Housing (Model GBSC0).
Replacement
Should a thermostat require replacement, use
plastic bell connectors (part # WR01X10466). Fill
each connector with RTV102 silicone then splice a
new thermostat into the harness.
RTV102

Evaporator Fan

The position of the fan blade in relation to the
shroud is important.
5/16" ± 0.03
1.0" ± 0.05 Target
AC DC Evaporator Fan Motor
The AC DC evaporator fan motor is connected in
parallel with the compressor and condenser fan
motor. The AC DC evaporator fan motor utilizes
115 VAC and operates when the compressor and
condenser fan motor are running.
DC Evaporator Fan Motor
The DC evaporator fan is the same fan used on
previous models; however, a signifi cant difference
is that the main control board neither requires nor
receives input from the fan feedback/rpm (blue)
wire. The fan utilizes a permanent magnet, 4-pole,
DC motor that operates at three different speeds:
high, medium, and low.
The speed of the fan is controlled by the voltage
output from the main control board. Voltage output
from the main control board to the fan is 13.6 VDC;
however, to regulate the speed of the fan, the main
control board uses pulse width modulation (PWM).
When operating, voltage is sent in pulses (much like
)
a duty cycle) as opposed to an uninterrupted fl ow.
This pulsing of 13.6 VDC produces effective voltage
being received at the motor, which is equivalent to a
reduction in voltage.
13.6 VDC
9.5 VDC
0 VDC
13.6 VDC
8 VDC
0 VDC
13.6 VDC
6.5 VDC
0 VDC
– 39 –
Blade tip
Air Flow
Motor
High Speed (9.5 VDC measured)
Medium Speed (8 VDC measured)
Low Speed (6.5 VDC measured)
(Continued next page)
Orifice