Lacquer
Protective coating or finish that dries to form a film by evaporation of a volatile constituent.
Ladder Diagram
Electrical diagram that indicates order of electrical devices in a specific electrical circuit.
Lag
Delay in response.
Lamp, Steri
Lamp that has a high-intensity ultraviolet ray used to kill bacteria. Also used in food storage cabinets and in air ducts.
Lapping
Smoothing a metal surface to high degree of refinement or accuracy using a fine abrasive.
Latent Heat
Heat energy absorbed in process of changing from of substance (melting, vaporization, fusion) without change in temperature or pressure.
Latent Heat of Condensation
Amount of heat released (lost) to change from a vapor (gas) to a liquid.
Latent Heat of Vaporization
Amount of heat required to change from a liquid to a vapor (gas).
Leak Detector
Device or instrument, such as a halide torch, an electronic sniffer, or soap solution, used to detect leaks.
Legionnaire's Decease Bacterium (LDB)
Is thought to be transmitted by airborne routes, possible by open air cooling towers or evaporative condensers in commercial systems. Disease is named after an outbreak of illness at an American Legion convention in July, 1976.
Limit Control
Control used o open or close electrical circuits as temperature or pressure limits are reached.
Liquefied Gases
A gas below a certain temperature and above a certain pressure, that becomes liquid.
Liquid
Substance whose molecules move freely among themselves,, but do not tend to separate like those of gases.
Liquid Absorbent
Chemical in liquid form that has the property to “take on” or absorb other fluids.
Liquid Desuperheater
Valve that permits small flow of refrigerant to enter low side of systems to cool suction gas.
Liquid Floodback
A surge of liquid returning to the compressor.
Liquid Indicator
Device located liquid line that provides a glass window through which liquid flow may be watched.
Liquid Line
Tube that carries liquid refrigerant from the condenser or liquid receiver to the refrigerant control mechanism.
Liquid Nitrogen
Nitrogen in liquid from used as a low-temperature refrigerant in expendable or chemical refrigerant systems.
Liquid Receiver
Cylinder (container) connected to condenser outlet for storage of liquid refrigerant in a system.
Liquid Receiver Service Value
Two-or three-way manual valve located at the outlet of the receiver and used for installation and service purposes. It is sometimes called the king valve.
Liquid Transfer Method
Method of liquid refrigerant recovery in which the air conditioning unit is pressurized and refrigerant is removed by the created pressure difference.
Liquid-Vapor Valve Refrigerant Cylinder
Dual hand valve on refrigerant cylinders that is used to release either gas or liquid refrigerant from the cylinder.
Listing
To tilt to one side due to an unbalanced load.
Liter
Metric unit of volume, equal to 61.03in3
Lithium Bromide
Chemical commonly used as the absorbent in absorption cooling system. Water would then be the refrigerant.
Localized Controllers
Independent energy control device located near the system it is controlling.
Locked Rotor Amperage
Initial current when initially closing a circuit, two to four times as high as the running current.
Locker Plant
Manufacturing plant designed to prepare freeze, and store food products.
Lockout Relay
A device that shuts down a circuit whenever a safety control device is open.
Low Pressure Safety Cutout
Motor protection device that senses low-side pressure. Control is wired in series with the motor and will shut off during periods of excessively low suction pressure. Also called low-side pressure indicator.
Low Side
The parts of a refrigeration system subject to the evaporator pressure.
Low-side Float Valve
Refrigerant control valve operated by level of liquid refrigerant in low-pressure side of system.
Low-side Pressure
Pressure in cooling side of refrigerating cycle.
Low-side Pressure Control
Device used to keep low-side evaporating pressure from dropping below certain pressure.
Low-side Pressure Limiter
See low-pressure safety cutout.
LP Fuel
Liquefied petroleum used as a fuel gas.