TriPac Glossary
60
cycles per second: See Hertz.
dehydrator: A device used to remove moisture from
refrigerant. Also called a drier.
discharge air temperature: The temperature of air leaving
the evaporator.
drier: See dehydrator.
evaporator: The part of the refrigeration system that absorbs
heat during the cooling cycle.
F: See Fahrenheit.
Fahrenheit: A unit of temperature measurement used in the
United States. Abbreviated “F.”
freeze up: 1) Failure of a refrigeration system to operate
normally due to moisture in the refrigerant and the formation
of ice at the expansion valve. The expansion valve may be
frozen shut or open, causing improper unit operation in either
case. 2) The formation of a solid ice mass over the evaporator
coil reducing air flow.
fuse: An electrical safety device (typically a cartridge)
inserted into an electrical circuit. It contains material that will
melt or break when the current is increased beyond a specific
value. When this occurs, the circuit is opened and electrical
current flow is stopped.
fusible link: An electrical safety device (typically a short
piece of wire) inserted into an electrical circuit. The wire melts
or breaks when the current is increased beyond a specific
value. When this occurs, the circuit is opened and electrical
current flow is stopped.
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.