Scotsman MFE400 - Manual (Page 12)

OPERATION: Refrigeration
Beginning at the compressor, the refrigerant is
compressed into a high temperature gas. The
discharge line directs this gas to the condenser. At
the condenser (air or water cooled) the gas is
cooled by either air or water and it then condenses
into a liquid. This high pressure liquid then goes
through the liquid line to the capillary tube. The
capillary tube meters liquid refrigerant into the
evaporator, the volume of liquid refrigerant
depending upon the temperature of the
evaporator; warmer evaporators get more
refrigerant and colder evaporators get less.
At the evaporator, the refrigerant enters an area of
relatively low pressure, where it can easily “boil off”
or evaporate. As it evaporates, it absorbs heat
from the evaporator and whatever is in contact
with it (such as the water inside it). After the
evaporator, the refrigerant, now a low pressure
vapor, goes through the suction line back to
compressor, where the cycle is repeated.
System Characteristics
Typical Low Side Pressure 13 -14 PSIG
Typical High Side Pressure
••
(air cooled) 137 - 170 PSIG
••
(water cooled) 135-140 PSIG
Typical auger drive motor amp draw: 2-8 - 3.1
Refrigerant Charge: 15 oz. of R-134a
EVAPORATOR
ACCUMULATOR
CAPILLARY TUBE
COMPRESSOR DRYER
CONDENSER
MFE400
May 1994
Page 12