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
!
©2003 Maytag Appliances Company
16022217 Rev. 0
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2. If the evaporator thermistor senses temperature
outside of 0-140 deg. F, all loads will be shut off and
the unit will not run.
The thermistor can be check by use of a multi-meter with
the ability to read resistance.
To check the thermistor:
1. Disconnect and remove the thermistor from the unit.
2. Use a reference temperature point that is known
(such as an ice bath) and measure the resistance
across the wire leads.
3. Check the recorded resistance with that in the table
below.
If measured resistance falls outside the resistance given
in the table within 4% of the value, the thermistor is bad
and will need to be replaced.
RESISTANCE VS. TEMPERATURE CHART
TEMPERATURE (C) TEMPERATURE (F) RESISTANCE (KOHMS)
-15 5 11.350
-10 14 8.918
-5 23 6.700
0 32 5.630
5 41 4.520
10 50 3.652
15 59 2.970
20 68 2.430
25 77 2.000
If the thermistor has been tested and is found to be good
then check the temperature of the evaporator plate and
the resistance of the thermistor. If the temperature of the
evaporator plate does not correspond to a proper
resistance from the thermistor then check for proper and
secure connection of the thermistor to the evaporator
plate bracket. The use of a heat sink compound can be
used between the thermistor and the evaporator bracket
if needed.
Grid-Cutter Transformer
The grid-cutter transformer is used to step down the
voltage to the grid-cutter to 12 VAC. The transformer is
on only from the start of a harvest cycle to 35 minutes
from the start of the production cycle. The transformer
itself can be checked by applying 120VAC to the marked
120V (for the hot lead) and COM (neutral lead) side of
the transformer and reading the 12V side using a
multimeter.
If no readout is found or readout is below 10VAC, replace
the transformer.
Grid-Cutter
The grid-cutter is used to cut cubes from the ice slab
formed on the evaporator. It uses low voltage, 12VAC, to
heat the wires. Wires are warm to the touch of a hand
when not under the load of a slab of ice. The grid-cutter
is on only from the start of a harvest cycle to 35 minutes
from the start of the production cycle.
There is no repair for the grid-cutter. It will have to be
replaced as an assembly. To test the grid-cutter:
Check the resistance at the outside grid-cutters
plug-in terminals
Note:
The middle terminal is not used.
If the resistance between the terminal of the plug
is 5.0-5.9 ohms, the grid-cutter is good. At any other
resistance readings, it will need to be replaced.
Check for continuity between terminals and the
grid-cutters stainless steel frame. If continuity is found,
check for wires that are not on the insulators.
Reservoir
The reservoir retains the water needed to produce an ice
slab. It will hold a maximum of 3 quarts of water.
Anything over 3 quarts will be drained in the reservoirs
overflow.
Anytime the reservoir is removed, it should be cleaned
with ice machine cleaner. Be sure to rinse the reservoir
before re-installing.
Circulation Pump
The circulation pump is used to circulate the water in the
reservoir over the evaporator. The circulation pump will
run only during ice production cycle and turn off in ice
harvest cycle.
The pump is a centrifugal impeller type pump. The pump
and motor are an assembly that cannot be repaired
separately.
To check the circulation pump (with the pump removed):
Make sure motor shaft turns freely. This can be
done by rotating the pumps drive shaft and observing
any excessive resistance.
Check for resistance between terminals. If no
resistance is found, replace the circulation pump.
Check for continuity between the hot and neutral
terminals and the pumps motor casing. If continuity is
found, replace the circulation pump.
Check current draw. Typical current draw will be
.36 amp without pump resistance. If excessive current
draw is found, check the pumps impeller for foreign
particles or severe build-up of mineral deposits.
