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A streetlight. - A single-phase secondary distribution circuit (fed from a transformer offscreen to the right) whose sole purpose is to provide power for the streetlight. It may therefore be exactly 48v, but some of these power supplies are actually regulated to 50v to match the typical behavior of older equipment. An A Class electrician may perform work unsupervised but is unable to work for profit or gain without having the further qualifications necessary to become a Registered Electrical Contractor (REC) or being in the employment of a person holding REC status. Depending on the power company's billing policies, CATV power supplies may be metered, what are electric cables or they may be billed on a flat-rate basis. The power supply illustrated here is metered; the meter is visible below the power supply. The amplifier housing also includes a power pack to accept power from the cable TV power supply and provide DC voltage to drive the amplifier modules. Each amplifier incorporates a DC power pack that rectifies this voltage and provides DC operating voltages for the amplifier circuitry. In the United States, electricians are divided into two primary categories: lineperson, who work on electric utility company distribution systems at higher voltages, and wiremen, who work with the lower voltages utilized inside buildings.

In 1928, the Federal Trade Commission launched a comprehensive inquiry into the entire electric power industry, as abuses mounted, from financial pyramid schemes and the stock market speculation of the "Roaring Twenties." The investigations culminated in the 1935 passage of President Franklin Roosevelt's Public Utility Holding Company Act, which forced the breakup of many holding companies, and several of American Electric Power's holdings were divested. Multipair telephone cable. - Two CATV power supplies, one for the public CATV network and one for the I-Net. These amplifiers require operating power; this power (at 60, 75, or 90 volts RMS) is provided by a CATV power supply similar to the one shown here, and delivered to the amplifiers over the CATV network itself. Voltage was stepped down to 100 volts using the Stanley transformer to power incandescent lamps at 23 businesses over 4,000 feet (1,200 m). In 1882, DC voltage could not easily be increased for long-distance transmission. Each T1 circuit requires two transmission paths, one in each direction. Prestressed concrete poles are often used in coastal areas subject to atmospheric corrosion (one manufacturer claims that "concrete poles are foremost in appearance, durability and maintenance-free service").

These poles are owned by, and located on property owned by, a railroad company. Even though there are three types of circuits on these poles, they are still non-joint poles because all circuits are owned by the same owner. Furthermore, there are no telephone or other non-broadband facilities on this pole. This pole supports: - Three-phase open-wire primary electric distribution. This particular concrete pole supports: - Static wire. This pole supports: - Three-phase primary electric distribution. Items on this pole include: Strand. Fiber owned by CATV companies is usually lashed to the same strand that supports the coaxial trunk cable; at this particular pole, the fiber bypasses the amplifier to feed other portions of the network. The secondary distribution wiring appears to be a duplex bundle in which the MGN serves as both neutral and mechanical supporting strand. Note that the fire-alarm wiring is open wire, and that it appears to be very close to the CATV cable.

NM cable usually contains one or more "hot" (current-carrying) wires, a neutral wire, and a ground wire. All circuits are open wire, implemented with uninsulated wire. They are a common sight today along suburban streets and country roads. T1 circuits, implemented over twisted-pair copper cables, are still in use today to carry voice channels over relatively short distances (up to 20 or 30 miles). Coaxial feeder cable. Feeder is used to transport signals over distances of a few city blocks. Coaxial trunk cable. Trunk is used to transport broadband signals over distances of a few miles, typically not more than than two or three, and almost never more than ten. Amplifier. The amplifier housing (see photo below) contains separate amplifier modules to amplify the trunk signal and to provide outputs to drive the feeder cables. Communications circuits provide voice and signal communications among equipment shelters and company offices. Signalling circuits control train-signal lights and safety equipment at grade crossings (gates, lights, bells). Safety equipment used and worn by electricians in Australia (including insulated rubber gloves and mats) needs to be tested regularly to ensure it is still protecting the worker.