RS1500000 Rev. 2
20
Component Testing
To avoid risk electrical shock, personal injury, or death,
always disconnect electrical power source to the freezer
before attempting to service, unless test procedures require
power to be connected. When removing any wiring from terminals they must be replaced on the same terminals.
Ensure all ground wires are connected before certifying unit as repaired and/or operational.
WARNING
!
Checking Timer
Unplug line cord from electrical outlet. Remove 1/4 Spin
Tight screws and remove the timer. Disconnect all wires
from timer and attach ohmmeter leads to terminals
specified in the accompanying chart. If no continuity is
indicated, timer has failed and must be replaced. When
replacing timer, connect wire leads to timer terminals.
Verify grounding wire is connected.
Ground
wire
Timer
mounting
screws
Ground
wire
Timer
Defrost Timer Mounting
To test
Turn timer
knob to
Check
between
terminals
Timer motor
circuit
Leave as is
1 and 3
Defrost circuit
1
st
click
1 and 2
Compressor
circuit
2
nd
click
1 and 4
Turn defrost timer one full turn clockwise to locate start
defrost cycle (1st click) and end defrost cycle (2nd click)
positions. The 1st and 2nd clicks are only a few degrees
of shaft rotation apart. Turn the shaft slowly and stop
immediately when the 1st click is heard.
Defrost Heater and Thermostat
No-Defrosting Models
Defrost heater is a radiant heater and will melt all frost
that collected during the proceeding 12 hour period when
operating properly. Failure to perform this function will
eventually cause an ice build-up between the coil fins,
blockage in air flow and unsatisfactory refrigeration.
Defrost heater extends across the bottom of freezer coil
above the built-in-drain trough. Heater is clamped at both
ends to a shield. Shield is attached to coil mounting
panel and is slotted to permit free drainage into the drain
trough.
Defrost thermostat is located on upper header of freezer
coil. Thermostat senses temperature of the header and
automatically shuts off the defrost heater when
temperature reaches 51°F (11°C).
To test defrost thermostat and defrost heater when the
freezer coil temperature is + 15°F (-9°C) or below, use a
wattmeter or an ohmmeter and proceed as follows:
1. Disconnect freezer line cord plug from electrical outlet
and plug it into wattmeter.
2. Plug-in wattmeter line cord into electrical outlet and
manually advance timer to defrost cycle.
3. Wattmeter should indicate approximately 430 watts
(total wattage of timer motor and defrost heater). If
indication is 3 watts, defrost heater or defrost
thermostat has failed. To isolate failed component,
proceed to step 4. However, if indication is 430 watts,
timer has (not advancing to defrost) failed and must
be replaced.
4. Disconnect freezer line cord plug from wattmeter.
5. Remove freezer coil cover and check defrost heater
for continuity. If heater shows continuity, defrost
thermostat has failed and must be replaced.
NOTE:
Set meter to X1 scale. If reading is
approximately 35 ohms, defrost thermostat and
defrost heater are operative.
