26 Del. Admin. Code § 3007-2.0
The following words and terms, as used in these regulations, shall have the following meanings, unless the context clearly indicates otherwise:
"Availability" means the measure of time a generating unit, transmission line, or other facility is capable of providing service, whether or not it actually is in service.
"Beginning restoration" includes the essential or required analysis of an interruption, the dispatching of an individual or crew to an affected area, and their arrival at the work site to begin the restoration process (normally inclusive of dispatch and response times).
"Benchmark" means the standard service measure of SAIFI, CAIDI and Forced Outage Rate as set forth in these regulations.
"Capacity" means the rated continuous load-carrying ability, expressed in megawatts ("MW") or megavolt-amperes ("MVA") of generation, transmission, or other electrical equipment.
"Contingency" means the unexpected failure or outage of a system component, such as a generator, transmission line, circuit breaker, switch, or other electrical element. A contingency may also include multiple components, which are related by situations leading to simultaneous component outages.
"Corrective action" means the maintenance, repair, or replacement of an EDC's utility system components and structures to allow them to function at an acceptable level of reliability.
"Corrective maintenance" means the unplanned maintenance work required to restore delivery facilities to a normal operating condition that allows them to function at an acceptable level of reliability.
"Customer Average Interruption Duration Index ('CAIDI')" represents the average time in minutes required to restore service to those customers that experienced sustained interruptions during the reporting period. CAIDI is defined as follows:
CAIDI = Sum of all Sustained Customer Interruption Durations per Reporting Period
Total Number of Sustained Customer Interruptions per Reporting Period
"Delivery Facilities" means the EDC's physical plant used to provide electric energy to Delaware retail customers, normally inclusive of distribution and transmission facilities.
"Dispatch time" is the elapsed time between receipt of a customer call and the dispatch of a service resource to address the customer's issue as tracked by the OMS.
"Distribution feeder" or "feeder " means a three-phase set of conductors emanating from a substation circuit breaker serving customers in a defined local distribution area. This includes three-phase, two-phase and single-phase branches that are normally isolated at all endpoints.
"Distribution facilities" means electric facilities located in Delaware that are owned by a public utility that operates at voltages of 34,500 volts or below and that are used to deliver electricity to customers, up through and including the point of physical connection with electric facilities owned by the customer.
"Electric Distribution Company " or "EDC" means a public utility owning and/or operating transmission and/or distribution facilities in this state.
"Electric distribution system " means that portion of an electric system, that delivers electric energy from transformation points on the transmission system to points of connection at the customers' premises.
"Electric service" means the supply, transmission, and distribution of electric energy as provided by an electric distribution company.
"Interruption" means the loss of electric service to one or more customers. It is the result of one or more component outages, depending on system configuration or other events. See "outage" and "major event." The types of interruption include momentary event, sustained and scheduled.
"Interruption, duration" means the period (measured in minutes) from the initiation of an interruption of electric service to a customer until such service has been restored to that customer. An interruption may require step restoration tracking to provide reliable index calculations.
"Interruption, momentary event " means an interruption of electric service to one or more customers, of which the duration is less than or equal to 5 minutes. This definition includes all reclosing operations, which occur within five minutes of the first interruption. For example, if a recloser or breaker operates two, three, or four times and then holds within five minutes, the event shall be considered one momentary event interruption.
"Interruption, scheduled" means an interruption of electric service that results when one or more components are deliberately taken out of service at a selected time, usually for the purposes of preventative maintenance, repair or construction. Scheduled interruptions, where attempts have been made to notify customers in advance, shall not be included in the SAIFI, CAIDI, or Forced Outage Rate calculations.
"Interruption, sustained" means an interruption of electric service to one or more customers that is not classified as a momentary event interruption and which is longer than five minutes in duration.
"Interrupting device" means a device, capable of being reclosed, whose purpose includes interrupting fault currents, isolating faulted components, disconnecting loads and restoring service. These devices can be manual, automatic, or motor operated. Examples include transmission and distribution breakers, line reclosers, motor operated switches, fuses or other devices.
"Major Event" means an event consistent with the I.E.E.E.1366, Guide For Electric Power Distribution Reliability Indices standard as approved and as may change over time. For purposes of this regulation, changes shall be considered to be in effect beginning January 1 of the first calendar year after the changed standard is adopted by the I.E.E.E. Major event interruptions shall be excluded from the EDC's SAIFI, CAIDI and Forced Outage Rate calculations for comparison to reliability benchmarks. Interruption data for major events shall be collected, and reported according to the reporting requirements set forth in this regulation.
"Outage" means the state of a component when it is not available to perform its intended function due to some event directly associated with that component. An outage may or may not cause an interruption of electric service to customers, depending on system configuration.
"Outage management system ('OMS')" means a software operating system that provides database information to effectively manage service interruptions and minimize customer outage times.
"PJM Interconnection, L.L.C. ('PJM')" means the independent system operator that is responsible for mid-Atlantic region wholesale energy markets and the interstate transmission of energy, or it's successor organization.
"Power quality" means the characteristics of electric power received by the customer, with the exception of sustained interruptions and momentary event interruptions. Characteristics of electric power that detract from its quality include waveform irregularities and voltage variations - either prolonged or transient. Power quality problems shall include, but are not limited to, disturbances such as high or low voltage, voltage spikes or transients, flicker and voltage sags, surges and short-time overvoltages, as well as harmonics and noise.
"Preventive maintenance" means the planned maintenance, usually performed to preclude forced or unplanned outages, and which allows delivery facilities to continue functioning at an acceptable level of reliability.
"Related projects" are individual projects whose completion is required, contingent, or dependent on each other for overall completion of the specified scope of work.
"Reliability" means the degree of performance of the elements of the bulk electric system that results in electricity being delivered to customers within accepted standards and in the amount desired. Reliability may be measured by the frequency, duration, and magnitude of adverse effects on the electric supply. Electric system reliability can be addressed by considering two basic and functional aspects of the electric system - Adequacy and Security. (See ERC definition - NERC's Reliability Assessment 2001-2010, dated October 16, 2001.)
Adequacy - The ability of the electric system to supply the aggregate electrical demand and energy requirements of customers at all times, taking into account scheduled and reasonably expected unscheduled outages of system elements.
Security - The ability of the electric system to withstand sudden disturbances such as electric short circuits or unanticipated loss of system elements. (See NERC definition - NERC's Reliability Assessment 2001-2010, dated October 16, 2001.)
As applied to distribution facilities, reliability is further described as the degree to which safe, proper and adequate electric service is supplied to customers without interruption.
"Repair time" is the elapsed time from the arrival of the service resource at the identified problem site to the correction of the customer's original concern as tracked by the OMS.
"Response time" is the elapsed time from dispatch of service resource to the arrival of the service resource at the identified problem site as tracked by the OMS.
"Step restoration" means the restoration of service to blocks of customers in an area until the entire area or circuit is restored.
"Sum of all Sustained Customer Interruption Durations" means the summation of the restoration time (in minutes) for each event times the number of interrupted customers for each step restoration of each interruption event during the reporting period.
"Supervisory Control And Data Acquisition ('SCADA')" is an electronic communication and control system that provides electrical system operating information and mechanisms to remotely control energy flows and equipment.
"System Average Interruption Duration Index ('SAIDI')" represents the average duration of sustained interruptions per customer. SAIDI is defined as:
SAIDI = Sum of all Sustained Customer Interruption Durations per Reporting Period
Total Number of Customers Served per Reporting Period
"System Average Interruption Frequency Index ('SAIFI')" represents the average frequency of sustained interruptions per customer during the reporting period. SAIFI is defined as:
SAIFI = Total Number of Sustained Customer Interruptions per Reporting Period
Total Number of Customers Served per Reporting Period
"Total Number of Sustained Customer Interruptions" means the sum of the number of interrupted customers for each interruption event during the reporting period. Customers who experienced multiple interruptions during the reporting period are counted for each interruption event the customer experienced during the reporting period.
"Total Number of Customers Served" means the number of customers provided with electric service by the distribution facility for which a reliability index is being calculated on the last day of the time period for which the reliability index is being calculated. This number should exclude all street lighting (dusk-to-dawn lighting, municipal street lighting, traffic lights) and sales to other electric utilities.
"Transmission facilities" means electric facilities located in Delaware and owned by a public utility that operates at voltages above 34,500 volts and that are used to transmit and deliver electricity to customers (including any customers taking electric service under interruptible rate schedules as of December 31, 1998) up through and including the point of physical connection with electric facilities owned by the customer.
26 Del. Admin. Code § 3007-2.0