74. In this Part:

“authorised person” means a person who is—

(a) competent for the purpose of this Part, in relation to which the expression is used,

(b) either an employer, a self-employed person, or an employee appointed or selected by the employer or self-employed person, and

(c) engaged in work or duties incidental to the generation, transformation, conversion switching, controlling, regulating, rectification, storage, transmission, distribution provision, measurement or use of electrical energy;

“circuit” means part of an electrical installation supplied from the same origin, which may be protected against overcurrents by the same protective device;

“circuit breaker” means an electro-mechanical device capable of making, carrying and breaking currents under normal circuit conditions and also capable of making, carrying for a specified time, and breaking currents under specified abnormal circuit conditions such as those of short circuit;

“conductive part” means a part capable of conducting current although not necessarily used for carrying current in normal conditions;

“conductor” means a conductor of electrical energy;

“danger” means risk of personal injury from—

(a) electric shock, electric burn, electrical explosion or arcing,

(b) fire or explosion caused by the use of electricity, or

(c) mechanical movement of electrically driven equipment,

and preventing danger in this Part shall be construed as preventing danger so far as is reasonably practicable;

“earthing” means the connection of the exposed conductive parts of an installation to the conductive mass of the earth;

“electrical equipment” includes any conductor or electric cable and any part of any machine apparatus or appliance intended to be used or installed for use for the generation transformation, conversion, switching, controlling, regulating, rectification, storage transmission, distribution, provision, measurement or use of electrical energy;

“electrical installation” means an assembly of associated electrical equipment fulfilling a specific purpose or purposes and having co-ordinated characteristics;

“higher voltage” means any voltage exceeding—

(a) 1,000 volts alternating current, or

(b) 1,500 volts direct current;

“isolation” means the disconnection and separation of electrical equipment from every source of electrical energy in such a way that the disconnection and separation is secure;

“live” means electrically energised;

“medical electrical equipment” means medical electrical equipment as defined in the Electro-Technical Council of Ireland (ETCI) document entitled “National Rules for Electrical Installations in Medically Used Rooms” or other equipment as may be prescribed by the Minister;

“overcurrent” means any current exceeding the rated value of the electrical equipment concerned;

“overhead line” means any electric line suspended above ground carrying or intended to carry electrical energy at a voltage exceeding 80 volts to earth;

“portable equipment” means equipment, including hand-held portable equipment, which—

(a) because of the manner in which it is to be used, requires to be moved while it is working,

(b) is designed so that it can be moved while it is working, or

(c) is moved from time to time between the periods during which it is working;

“residual current device” means an electro mechanical switching device intended to disconnect a circuit when the residual current attains a stated value under specific conditions;

“substation” means any building, enclosure or other structure, or any part thereof, which -

(a) is large enough to enable a person to enter after the electrical equipment therein is in position, and

(b) contains equipment for transforming or converting electrical energy either to or from higher voltage (not being equipment for transforming or converting electrical energy solely for the operation of switchgear or instruments),

and includes that equipment, together with any other equipment for switching, controlling or otherwise regulating electrical energy;

“switch room” means a room intended primarily to house electrical switching and distribution equipment for a building;

“underground cable” means any electric cable below ground carrying or intended to carry electrical energy at a voltage exceeding 80 volts to earth.