Raceways -- A metal or plastic channel used for loosely holding electrical and telephone wires in buildings. A raceway is usually located in the floor and is usually encased on three or four sides by concrete.

Radio Frequency -- The frequencies in the electromagnetic spectrum that are used for radio communications.

Rated Temperature -- The maximum temperature at which an electric component can operate for extended periods without loss of its basic properties.

Rated Voltage -- That maximum voltage at which an electrical component can operate for extended periods without undue degradation or safety hazard.

Ray (Fiber Optic) -- A straight line, representing light, perpendicular to the light wave front and traveling in the same direction. At a boundary surface, or interface such as the surface between a fiber core and cladding, the ray may change direction suddenly, but it remains a straight line.

REA -- Rural Electrification Administration of the U.S. Department of Agriculture.

Reactance (X) -- That part of the impedance of an alternating current circuit which is due to capacitance or inductance.

Ready Access Closure -- A special type of cable closure having a Neoprene or plastic hood which can be removed easily for termination connections. Used only for PIC cable as the closures are neither gas or moisture tight.

Receiver -- An electronic package that converts light energy to electrical energy in a fiber optic system.

Redrawn -- The drawing of wire which has already been drawn to an intermediate size, through a series of dies, to reach a desired wire size.

Reducing Joint -- A joint between two lengths of cable where the conductors are not the same size.

Reduction Gear -- The gear device used to reduce the speed between the drive motor and extruder screw. Supplementary speed reductions means may also be used, such as belts and sheaves.

Reel -- A revolvable flanged device made of wood, plastic and/or metal which is used for winding flexible metal wire or cable.

Reel Pak Cartons -- ESSEX GROUP, INC. trademark for the reel cartons housing small wires and cables less than six pair, 22 or 24 AWG. Wires and cables are specially wound in 1000 foot coils and placed in Reel Pak cartons. Wires are dispensed with no kinks, tangles, or coil back.

Reelex Box -- A carton of the style patented by Winding, Inc. used to contain a coil of wire packaged by Reelex machinery.

Reference Edge -- Edge of cable or conductor from which measurements are made. Sometimes indicated by a thread, identification stripe, or printing. Conductors are usually identified by their sequential position from the reference edge, with number one conductor closest to this edge. Sometimes called index edge.

Reflection -- The change in direction (or return) of waves striking a surface. For example, electromagnetic energy reflections can occur at an impedance mismatch in a transmission line, causing standing waves.

Reflection (Fiber Optic) -- Change in direction of a light wave, or light ray when its strikes a surface.

Reflection Loss -- The part of a signal which is lost due to reflection of power at a line discontinuity.

Reflow Soldering -- The process of connecting two solder-coated conductive surfaces by remelting of the solder to cause fusion.

Refraction (Fiber Optic) -- The bending of lightwaves or rays as they go from one material to another due to the difference in velocities in the materials.

Refractive Index (Fiber Optic) -- The ratio of the velocity of light in a vacuum to its velocity in a material such as a fiber. Also, the ratio of the sine of the angle of incidence of light on the material to the angle of refraction to the light. Refractive index of any material varies with the wavelength of the light. Also called index of refraction. In a fiber, core refractive index must be greater than that of the cladding.

Registration -- Alignment of one object with relation to another. Also called Register.

Reinforced Sheath -- The outermost covering of a cable that has a cable sheath constructed in layers with a reinforcing material, usually a braided fiber, molded in place between layers.

Relative Humidity -- The ratio of the quantity of water vapor present in the atmosphere to the quantity which would saturate it at the existing temperature.

Repeater -- A receiver and transmitter combination used to regenerate an attenuated signal.

Resin -- Any of a class of solid or semi-solid organic products of natural or synthetic origin, generally of high molecular weight with no definite melting point. Most resins are polymers.

Resistance -- The property of a wire or conductor that determines the current flow for a given applied voltage measured in ohms.

Resistance Unbalance -- The difference in resistance between two wires of a pair.

Resistive Conductor -- A conductor used primarily because it possesses the property of high electric resistance.

Resistivity -- The ability of a material to resist passage of electrical current either through its bulk or on a surface. The unit of volume resistivity is the Ohm-Cm of surface resistivity, the Ohm.

Resonance -- An AC circuit condition in which inductive and capacitive reactances interact to cause a minimum or maximum circuit impedance.

Respool -- To rerun material from one package spool to another for various purposes, such as to verify lengths, inspect the defect, etc.

Retractile Cord -- A cord having specially treated insulation or jacket so that it will retract like a spring. Retractability may be added to all or part of a cord's length.

RF Cable -- Designed for use for frequencies above approximately 1 megacycle.

RF Connector -- Connector used for connecting or terminating coaxial cable.

RFI -- Radio frequency interference.

RG Cable -- Coaxial cable covered by JAN-C-17 or MIL-C-17.

RG/U -- "RG" is the military designation for coaxial cable and "U" stands for "general utility".

RHH -- NEC conductor type designation for conductors with heat resistant rubber or XLPE insulation, for use in wet or dry locations, 90°C.

RHW -- NEC conductor type designation for conductors with heat and moisture resistant rubber or XLPE insulation, for use in wet or dry locations, 75°C.

Ribbon Burner Flame Test -- A cable tray flame test using a 70,000 BTU/hr ribbon burner as the flame source. The test procedure first appeared in IEEE Std 383-1974 for qualifying nuclear generating station cables. This test has since been adopted for cables used in fossil-fueled generating stations and in substations of electric utilities. It has entered the industrial cable market by being written into several UL standards (TC Tray Cable, for CT use). The Navy (MIL-C-915, MIL-C-24643) and Coast Guard (IEEE-45) have also adopted this test for their cables. The insurance industry is exerting pressure to have this test upgraded to a 210,000 BTU/hr rating. ICA has published a guide (T-29-520) for conducting a 210,000 BTU/hr flame test on cables in a tray.

Ribbon Cable -- A cable consisting of two or more conductors laid parallel in one plane and held in place by some means. Usually has a molded polyethylene insulation.

Ridge Marker -- One or more ridges running laterally along the outer surface of plastic wire for purposes of identification. Readily perceptible to sight and touch, they are formed by minute notching of the extrusion die. Usually associated with aerial drop wire.

Ring -- (1) An audible signal by a bell. (2) An application of current to ring a bell or operate an alerting signal. (3) That side of a two wire telephone circuit or loop which is connected to the negative side of a battery located at the telephone company's central office. It's comparable to the "hot" side of a residential lighting circuit.

Ring Banding -- A method of color coding insulated conductors by means of a small band of colored ink applied circumferentially at regular intervals along the axis of this insulated conductor.

Ring Wire -- The second wire of a pair, of which the first wire is the "tip".

Ringing Out -- The process of locating or identifying specific conductive paths by means of passing current through selected conductors.

Rip-Cord -- A cord placed usually in inside wires and cables directly under the jacket of a cable or wire in order to facilitate stripping and removal of the jacket.

RMS -- Root mean square. When the term is applied to alternating voltage and current it means the effective value; i.e., it produces the same heating effect as a direct current or voltage of the same magnitude.

Rockwell Hardness -- A test for hardness (resistance to indentation) of a material in which a hardened steel ball or diamond point is pressed into the material under test.

Rod Mill -- A factory in which copper rod is drawn down to a smaller size. This may then be sold to other wire mills for drawing to still smaller sizes.

Roentgen -- The amount of radiation that will produce one electrostatic unit of ions per cubic centimeter volume.

Rolling Mill -- Plant where copper bars or ingots are rolled into copper rod.

Romex -- Non-metallic sheath cable.

Root Mean Square -- The effective value of an alternating periodic voltage or current.

Rope Strand -- A conductor composed of a center group of twisted strands surrounded by one or more layers of similar groups of twisted strands.

Rope Unilay -- A group of stranded conductors assembled in a unilay manner, the direction of lay of the unilay rope is left hand.

Rope-Lay Conductor or Cable -- A cable composed of a central core surrounded by one or more layers of helically laid groups of wires. (Note: this kind of cable differs from a concentric-lay conductor in that the main strands are themselves stranded, in the most common type of rope-lay conductor or cable, all wires are of the same size and the central core is a concentric lay conductor.)

Round Wire -- A wire circular in cross-section as opposed to flat, square, etc.

Round Wire Shields -- Shields constructed from bare, tinned or silver-plated copper wire. Three types of round wire shields include braided, spiral and reverse spiral.

Routing -- The path followed by a cable or conductor.

RS-232C -- A technical specification published by the Electronic Industries Association (EIA) that established mechanical and electrical interface requirements between terminals, computers, modems and communications lines.

RS-422 -- A high-speed electrical interface defined by the CCITT (Consultative Committee of International Telegraph and Telephone), supporting data rates of up to 768 Kbps over up to 300 feet of cable.

Rubber (Wire Insulation) -- A general term used to describe wire insulations made of thermosetting elastomers, such as natural or synthetic rubbers, EPR, Neoprene, Hypalon, butyl rubber and others.

Rupture -- In breaking strength or tensile strength tests, the point at which a material physically comes apart as opposed to yield strength, elongation, etc.

Rural Electrical Administration (REA) -- In 1948, the telephone amendment to the Rural Electrification Act was passed under the Rural Electrical Administration (REA) to ensure universal telephone service and area coverage at reasonable and affordable rates served by rural telephone companies and cooperatives. They developed Plant Engineering (PE) specifications for various outside and inside telecommunication cables. Those current include: PO-22 Aerial Underground Telephone Cable--Air Core Solid Conductor PE-39 Filled Telephone Cables--Solid Conductor Insulation PE-89 Filled Telephone Cables--Expanded or Cellular Insulation.