Electrolux BEVERAGE CENTER II, Service Manual

Page: 55 / 77

54
Thermostat
The Thermostat is a single-pole, single throw (SPST),
bimetallic, disk-type, thermal switch. It automatically
starts the Harvest Cycle when the ice is frozen. The
Thermostat closes at a temperature of 18°F ± 6°. Wired
in series with the Mold Heater, the Thermostat acts as
a safety device against overheating in the event of
mechanical failure. A thermal mastic bond is provided
where the Thermostat is mounted against the Mold. A
gasket prevents water from leaking into the support
housing.
Sensing Arm & Linkage
The Sensing Arm is cam-driven and operates a switch
that controls the quantity of ice produced. In the Harvest
Cycle, the arm is raised and lowered during each of the
two revolutions of the timing cam. If the Sensing Arm
comes to rest on top of ice in the storage compartment
during either revolution, the switch will remain open and
stop the Ice Maker at the end of that revolution. When
sufficient ice is removed from the Storage Container,
the Sensing Arm lowers and ice production resumes.
To manually stop the Ice Maker, raise the Sensing Arm
until it locks in the upper position. Operation is resumed
when the Sensing Arm is manually lowered.
Timing Switches (See Figure F2)
The three Timing Switches used are single- pole, double
throw (SPDT). They are identical except for function, and
can be used interchangeably.
1. Hold Switch - Assures completion of a revolution
once the Ice Maker operation has started.
2. Water Fill Switch - Opens the Water Valve during
the Fill Cycle. It is the only adjustable component in
the Ice Maker.
3. Shut-Off Switch - Stops Ice Maker operation when
the Storage Container is full of Ice. The switch is
opened after the Sensing Arm is raised to its most
upright position. The switch is mounted to the top
right wall of the Ice Maker Support. (Not shown in
Figure F2)
Thermal Cut-Out (TCO)
The Thermal Cut-Out is a one-time limit fuse used as a
safety device. It is located under the mounting plate, in
the head of the Ice Maker, between the Thermostat and
wire connector.
If the Thermal Cut-Out opens, the cause of failure must
be determined and corrected prior to replacing the TCO.
Normals causes of the TCO failing are a bad Thermostat
or a shorted coil on the water valve.
Timing Cam & Coupler
Three separate cams are combined in one molded Delrin
part:
1. Inner Cam operates Shut-Off Switch lever arm.
2. Center Cam operates Hold Switch.
3. Outer Cam operates Water Fill Switch.
One Cam end is attached to a large Timing Gear. The
other Cam end is coupled to the Ejector.
Timing Gear
This large molded plastic gear is driven by the Motor
and, in turn, rotates the Cam and Ejector. A “D” shaped
hole in the gear fits over the Timing Cam Hub. Spacer
tabs on the backside of the gear prevent the gear from
binding on the mounting plate.
Motor
A low wattage, stall-type Motor drives the Timing Gear.
This gear turns the Timing Cam and Ejector Blades
approximately one revolution every three minutes
(1/3 RPM).
Fill Trough
The Fill Trough is molded nylon. It supports the Inlet
Tube and directs the water into the Mold. It also forms
a bearing for one end of the Ejector Blades.
Wiring
A four-prong plug connects the Ice Maker wiring to the
cabinet wiring harness. (See Figure F3.) The Ice Maker
Assembly is wired across the line and will harvest in
either the Refrigeration or Defrost Cycles. A wiring
diagram is located inside the front cover of the Ice Maker.
Figure F3
Figure F2