220 Mass. Reg. 125.40
The following definitions are for use with the Massachusetts Code for the Installation and Maintenance of Electric Transmission Lines. For other use and for definitions not contained herein, see Definitions of Electrical Terms, ANSI C42.35.
Circuit. A conducting part or a system of conducting parts through which an electric current is intended to flow.
Conductor. A wire or combination of wires not insulated from one another, suitable for carrying electric current.
Grounding Conductor. A conductor which is used to connect the equipment or structure with a grounding system.
Department. The Massachusetts Department of Public Utilities.
Ground. A conducting connection, whether intentional or accidental, by which an electric circuit is connected to the earth, or to some conducting body, of relatively large extent, which serves in place of earth. It is used for establishing and maintaining the potential of the earth (or of the conducting body) or approximately that potential, on conductors connected to it, and for conducting ground current to and from the earth (or the conducting body).
(a) Grounded. Grounded means that the system, circuit, or apparatus referred to is provided with a ground.
(b) Effectively Grounded. Grounded through a grounding connection of sufficiently low impedance (inherent or intentionally added or both) that fault grounds which may occur cannot build up voltages in excess of limits established for apparatus, circuits, or systems so grounded.
(c) Effectively Grounded System. A system in which, for all points on the system or specified portion thereof in the ratio of zero-sequence reactance to positive-sequence reactance is positive and not greater than three and the ratio of zero-sequence resistance to positive-sequence reactance is positive and not greater than one for any condition of operation and for any amount of connected generator capacity.
Guarded. Covered, shielded, fenced, enclosed or otherwise protected, by means of suitable covers or casings, barrier rails or screens, mats or platforms, to remove the liability of dangerous contact or approach by persons or objects to a point of danger. Wires which are insulated but not otherwise protected are not considered as guarded.
Guy. A tension member having one end secured to a fixed object and the other end attached to a pole, crossarm or other structural part which it supports.
Anchor Guy. A tension member having one end secured in the ground and the other end attached to a pole, crossarm or other structural part which it supports.
Insulated. Separated from other conducting surfaces by a dielectric permanently offering a high resistance to the passage of current and to disruptive discharge. When any object is said to be insulated, it is understood to be insulated in suitable manner for the conditions to which it is subjected. Otherwise, it is, within the purpose of 220 CMR 125.00, uninsulated.
Isolated. Means that an object is not readily accessible to persons unless special means for access are used.
Lines.
(a) Communication Lines. The conductors and their supporting or containing structures which are located outside of buildings and are used for public or private signal or communication service, and which operate at not exceeding 400 V to ground or 750 V between any two points of the circuit, and the transmitted power of which does not exceed 150 W. When operating at less than 150 V no limit is placed on the capacity of the system. Telephone, telegraph, railroad-signal, messenger-call, fire, police-alarm, community television antenna and other systems conforming with the above are included. Lines used for signaling purposes, but not included under the above definition, are considered as supply lines of the same voltage and are to be so run.
(b) Electric-Supply Lines. Those conductors and their necessary supporting or containing structures which are located entirely outside of buildings and are used for transmitting electric energy at a phase to phase voltage less than 50,000 V. Does not include open wiring on buildings, in yards or similar locations where spans are less than 20 feet, and all the precautions required for stations or utilization equipment, as the case may be, are observed.
Railway sign allines of more than 400 V to ground are always supply lines within the meaning of 220 CMR 125.00, and those of less than 400 V may be considered as supply lines, if so run and operated throughout.
(c) Transmission Lines. Those conductors and their necessary supporting or containing structures which are located entirely outside of buildings and are used for transmitting electric energy at a phase to phase voltage exceeding 50,000 V.
(10) Reconstruction. Replacement of any portion of an existing installation by new equipment or construction. Reconstruction does not include ordinary maintenance replacements.
(11) Sag.
(a) Final Unloaded Sag. The sag of a conductor after it has been installed for a long period of time or after it has been subjected to external load for an appreciable period of time and the loading removed.
(b) Initial Unloaded Sag. The sag of a conductor immediately after installation.
(c) Unloaded Sag of a Conductor at Any Point in a Span. The distance measured vertically from the particular point in the conductor to a straight line between its two points of support, without any external load.
(12) Span Wire. A wire or cable used as an auxiliary support for wires, cables or equipment. While not normally used to carry current, it may do so under certain abnormal conditions.
(13) Tension.
(a) Final Unloaded Conductor Tension. The longitudinal tension in a conductor after it has been installed for a long period of time after it has been subjected to external load for an appreciable period of time and the loading removed.
(b) Initial Conductor Tension. The longitudinal tension in a conductor immediately after installation.
(14) Voltage.
(a) Voltage of an Effectively Grounded Circuit. The highest effective voltage between any conductor and ground unless otherwise indicated.
(b) Voltage of a Circuit Not Effectively Grounded. The highest effective voltage between any two conductors unless otherwise indicated.
If one circuit is directly connected to another circuit of higher voltage (as in the case of an auto-transformer), both are considered as of the higher voltage, unless the circuit of lower voltage is effectively grounded, in which case its voltage is not determined by the circuit of higher voltage. Direct connection implies electric connection as distinguished from connection merely through electromagnetic or electrostatic induction.
(c) Voltage to Ground of an Effectively Grounded Circuit. The highest effective voltage between any conductor of the circuit and that point of the circuit which is grounded.
(d) Voltage to Ground of a Conductor of an Effectively Grounded Circuit. The highest effective voltage between such conductor and that point or conductor of the circuit which is grounded.
220 CMR 125.40