Thermo King Precedent S-600, Operator'S Manual

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Glossary
198
HCFC: Hydrochlorofluorocarbon. A chlorine-based
refrigerant containing hydrogen, chlorine, fluorine and carbon.
Example: R22. Because chlorine damages the earth’s
atmosphere, in many countries, it is illegal to release this type
of refrigerant to the atmosphere. HCFC refrigerants are not
used in modern Thermo King units.
Hertz: A unit of frequency equal to one cycle per second.
Abbreviated “Hz.”
HFC: A refrigerant consisting of hydrogen, fluorine and
carbon. Examples: R134a and 404A. HFC refrigerants contain
no chlorine and are, therefore, considered “safe” for the
environment.
high pressure relief valve: A safety valve on the
refrigeration system that allows refrigerant to escape from the
system if pressure exceeds a predetermined value.
hp (horsepower): A unit of power equivalent to 746 watts
or 550 foot-pounds per second.
HPCO (High Pressure Cut Out Switch): A
pressure-operated switch that opens to stop unit operation
when discharge pressure reaches a predetermined maximum.
invertible: A multi-temperature truck or trailer unit designed
to allow the placement of deep-frozen cargo in any
compartment. See
Multi-Temp.
kPa: Kilopascals. A metric unit of pressure. 1 kPa = 0.01 bar =
0.145 psi.
load: 1) The product being refrigerated and transported.
2) The amount of heat being removed by the refrigeration
system. (For example, a compressor is under a heavy heat load
when expected to cool a very warm box.)
LPCO (Low Pressure Cut Out Switch): A
pressure-operated switch that opens to stop unit operation
when suction pressure reaches a predetermined minimum.
modulation: An optional system that reduces load (product)
dehydration and avoids “top freeze.”
movable bulkhead: A thick, insulated, portable wall-like
device used to compartmentalize a temperature-controlled
truck or trailer. See
bulkhead
.
Multi-Temp: A Thermo King truck or trailer unit capable of
maintaining different set-points in multiple compartments.