Glossary of Electric Utility Industry Terms
Raceway – A rectangular trough that carries insulated conductors.
Radar – A troubleshooting device used to locate holes in underground cable. It sends a signal down the cable that bounces back to the device once it reaches the hole in the cable. A computer uses the returning signal to display exactly where the hole is located. (CAEDS. EDS, IESO)
Rectifier – An electrical device that converts alternating current to direct current. (EUSO, IESO, System operator classes)
REA – See Rural Electrification Administration
Reactive Charge – A charge implemented by electric utilities, on commercial and industrial customers, if the ratio of work producing power to the total power drops below a level set by the electric utility. A reactive charge is also called a power-factor charge or a kVar charge (EUSO, IESO, System operator classes)
Reactive Power – Two types of non-work producing power. One type is used to magnetize coils and the other type is to charge capacitors. Both are measured in Volt-Ampere Reactive or VAr. (EUSO, IESO, System operator classes)
REC – Rural electric cooperative.
Recloser – A circuit breaker that opens as a normal circuit breaker during a fault, but which then automatically recloses on its own after a preset amount of time. (EUSO, IESO, CAEDS, EDS, System operator classes)
Re-conductor – To Replace a conductor with another conductor. (EUSO, IESO, CAEDS, EDS)
Re-conductoring - Replacing a conductor with another conductor. (EUSO, IESO, CAEDS, EDS)
Regional Transmission Organization - An organization responsible for the second-by-second operation and control of the transmission systems of several utilities. It is independent of each utility’s control, and serves each utility equally. It is the same as an independent system operator (ISO), but exercises control over a larger geographic area. (EUSO, System operator classes)
Relay – There are two general types of relays, control and protective. A control relay is an electronic or electro-mechanical device used to allow a circuit to control one or more other functions or devices. Protective relays control alarms, circuit breakers or other devices designed to prevent damage to equipment and/or people. When the term relay is used, it usually refers to a protective relay. Discussions referring to control relays usually occur among electrical engineers, electricians and technicians. (EUSO, CAEDS, EDS, IESO, System operator classes)
Relay Operation – Virtually always, this term refers to a protective relay detecting a problem and responding accordingly. (EUSO, CAEDS, EDS, IESO, System operator classes)
Relayed Out – This term refers to a protective relay causing a circuit breaker or circuit switcher to open, thus disconnecting a circuit, component or system from the source. (EUSO, CAEDS, EDS, IESO, System operator classes)
Reliability First Corporation – RFC -See NERC. (EUSO, System operator classes)
Remote Terminal Unit – A transducer and analog-to-digital converter used to take some type of measurement and convert it into a signal that a communication system can send to a remotely located computer.
RFC– Reliability First Corporation - See NERC. (EUSO, System operator classes)
Ridge Wire - A steel cable that is installed above the phase conductors in a distribution or transmission line. The steel cable is grounded. The purpose of the steel cable is to protect the phases from lightning strikes. Lightning will usually strike the steel cable and be diverted into the earth. Ridge wire is a term used in parts of Alabama. It is also called shield wire, static wire, overhead ground wire, and in Canada, sky wire. (EUSO)
Riser – A pipe containing insulated wire or cable that “rises” out of the earth. Risers are are found mounted on poles in the field and poles or other structures in substations. (EUSO-photo, IESO-photo)
Rolling Black-out - When there are too many customers connected to the system, the utility sometimes will deliberately disconnect the excess customers. This is called a black-out. Rather than disconnect one group of customers for a long period of time, the utility control center will disconnect a group of customers for a period of time, such as 15 minutes. After the 15 minutes, the control center will disconnect another group of customers and restore power to the first group. The control center will then disconnect a third group and restore power to the second group that was disconnected. (EUSO, System operator classes)
RTO – See Regional Transmission Organization
RTU – An acronym for Remote Terminal Unit. A remote terminal unit is a transducer and an analog-to-digital converter used to take some type of measurement and convert it into a signal that a communication system can send to a remotely located computer.
Rural Electrification Administration – Formed in 1933, by Executive Order, as a part of the U.S. Department of Agriculture with the mission to administer loan programs for electric and telephone service in rural America. It was abolished in 1994 and its functions were assumed by the Rural Utilities Service.
Rural Utilities Service – Formed in 1994 a part of the U.S. Department of Agriculture with the mission to help rural utilities expand and keep technology current. (The Rural Electrification Administration had this mission from 1933 until 1994.) www.usda.gov/rus/
Runner – A term used for the turbine in a hydroelectric plant. The runner, or turbine, is the component that is actually in contact with the water and is being turned by the flow of water.
RUS – See Rural Utilities Service