A. Unless a surface transformer is isolated by elevation to a height of eight feet or more above the ground, it shall be enclosed in a transformer house or surrounded by a suitable fence at least six feet high. If the enclosure or fence is made of metal, such enclosure or fence shall be grounded effectively. The gate or door to the enclosure shall be kept locked at all times unless an authorized person is present.
B. Any surface transformer that contains flammable oil and is installed where it presents a fire hazard shall be provided with a means to drain or confine the oil in the event of a rupture of the transformer casing.
C. Suitable warning signs shall be posted conspicuously at every transformer station on the surface.
D. Every transformer station on the surface shall be kept free of nonessential combustible materials and refuse.
E. No electrical work shall be performed on any low-voltage, medium-voltage, or high-voltage distribution circuit or equipment except by (i) a certified person or (ii) a person who is trained to perform electrical work and to maintain electrical equipment and who is working under the direct supervision of a certified person. Every high-voltage circuit shall be grounded before repair work is performed. Disconnecting devices shall be locked out and suitably tagged by the person who performs electrical or mechanical work on such a circuit or on any equipment connected to the circuit. However, in a case in which such locking out is not possible, such devices shall be opened and suitably tagged by such person. Each lock and tag shall be removed only by the person who installed it or, if such person is unavailable, by a certified person who is authorized by the operator or his agent. However, an employee may, where necessary, repair energized trolley wires if he wears insulated shoes and lineman’s gloves.
F. This section does not prohibit a certified electrical repairman from making checks on or troubleshooting an energized circuit or an authorized person from performing repairs or maintenance on equipment once the power is off and the equipment is blocked against motion, except where motion is necessary to make adjustments.