Servend MDH-302 Series, Installation, Use & Care Manual

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Section 3 Operation
Part Number 020003999 6/14
3-5
ICE STORAGE AND DISPENSING
As the customer presses the rocking chute, the arm at
the top left rear of the chute pushes upward on the door
lock. The door opens until it contacts the stops in the
mounting brackets. The plastic arm on the ice chute also
activates the lever of the ice dispensing switch. When
activated, the micro switch starts the gear motor. The
gear motor turns the paddle wheel and agitator arm.
The paddlewheel carries ice. Periodic agitation is
standard on the 30" and larger dispensers. During
periodic agitation, the paddle wheel and agitator turn for
approximately three seconds every three and one half-
hours. The door lock prevents ice from being dispensed
during the agitation cycle.
Rocking Chute Ice Dispensing
As the customer presses the rocking chute, the arm at
the top left rear of the chute pushes upward on the door
lock. The door opens until it contacts the stops in the
mounting brackets. The plastic arm on the ice chute also
activates the lever of the ice dispensing switch. When
activated, the micro switch starts the gear motor. The
gear motor turns the paddle wheel and agitator bar.
Crushed Ice Dispensing
As a customer presses the ice chute the rocking chute
door lifts and actuates micro switch which initiates the
crushed ice dispensing process. When activated, the
micro switch starts the gear motor and ice crusher
motor. The gear motor turns the paddle wheel and U-bar
agitator. The paddle wheel carries ice to the crusher
assembly. Once the ice reaches the crusher housing,
four stationary blades and three rotating blades crush
the ice and push it through the opening in the ice crusher
housing. The crushed ice then falls through the opening
into the ice chute, and into the customer’s cup.
Selectable Ice Sequence of Operation
As a customer presses the ice chute or pushes the
sanitary lever towards the unit with their cup, with
“crushed” selected on the ice selection pad, the rocking
chute door lifts and actuates micro switch which initiates
the crushed ice dispensing process. The micro switch is
activated when the lever is approximately 1/4 inch from
reaching the splash panel of the unit. When activated,
the micro switch starts the gear motor and ice crusher
motor. The gear motor turns the paddle wheel and U-bar
agitator. The paddle wheel carries ice to the crusher
assembly. Once the ice reaches the crusher housing,
four stationary blades and three rotating blades crush
the ice and push it through the opening in the ice crusher
housing. The crushed ice then falls through the opening
into the ice chute, and into the customer’s cup. If the
merchandiser is removed, no power is available to the
crusher or gear motor and no ice can be crushed and/or
dispensed.
CARBONATION
The purpose of the carbonator is to take regular tap
water at street water pressure (minimum 20 PSI,
maximum 80 PSI, dynamic or flowing pressure), 1/2"
water line and increase the water to beverage system
pressure (usually 100 PSI). This water is then combined
with the CO
2
gas. Because the water and gas are at the
same pressure, the CO
2
will dissolve into the water.
Chilling the mixture before dispensing will assist in
locking the carbon dioxide into the water. After
dispensing, the CO
2
may be unlocked from the liquid.
The CO
2
will gradually leave the liquid due to pressure
and temperature changes.
Components
The components of the carbonator are: water pump, an
electric motor to operate the pump, carbonator tank
where the water and CO
2
mix, and a water level control.
Operation
Carbon Dioxide (CO
2
) leaves the storage tank and
arrives at the carbonator tank through the gas inlet.
Water supply enters the carbonator pump inlet at regular
street water line pressure (minimum 20 PSI, maximum
80 PSI, dynamic or flowing pressure). The water pump
increases the pressure of the water, which allows the
water to flow into the carbonator tank. The CO
2
and the
water mix together in the carbonator to produce the
carbonated water that is then sent to the soda dispenser.
The agitation of the water and CO
2
together in the tank
under high pressure creates the soda water. The quality
of carbonation (percent of CO
2
mixed in the water)
increases as the water temperature decreases and
exposure time increases.
The water level in the carbonator tank is controlled by a
water level control in the tank. This control turns the
pump motor off and on to maintain a preset level of liquid
in the tank. The water level control may be electronic
probes or a mechanical float.