Ohio Code § 1567.18

§ 1567.18.

When alternating current is used underground in mines, the following rules apply: (A) On all low voltage circuits all wires shall be protected by a switch and an automatic

overload circuit breaker on each wire of the circuit, except that fuses may be substituted

for circuit breakers in the case of lighting circuits and in the case of power circuits

transmitting twenty-five kilowatts or less.  All wires shall be insulated with a standard insulation and shall be placed between

trolley wire and rib or on the rib as close to the roof as practicable and securely

supported upon hangers efficiently insulated.  Additional switches shall be installed in all branch circuits.  All points of connection shall be properly protected so that persons cannot inadvertently

come in contact therewith.  No voltage in excess of two hundred sixty volts measured at the nearest switchboard

shall be used in mobile machinery except with the written approval of the chief of

the division of mineral resources management. (B) When high voltage circuits are used, all wires shall be provided with a suitable

ammeter and protected by an oil-break switch on each wire of the circuit, such switch

to be equipped with an automatic overload trip.  All wires shall be insulated with a standard insulation at least fifty per cent

higher than the standard for the commercial rated voltage between conductors and ground

and installed in conduit or be lead covered with an additional covering of steel armor

wire or steel tape, and all wire shall be subject to carrying capacity according to

the rules of the national board of fire underwriters.  This cable may be installed either in or on the bottom or in the location prescribed

for direct current feed lines, except no further insulation shall be required than

specified in this section. (C) No voltage in excess of eight thousand volts between conductor and ground may be

used to operate semipermanent and permanent machinery except with the written approval

of the chief.  All installations shall be made in accordance with the accepted electrical standards

and practices, especially with regard to protective switches, insulation materials,

clearance danger signs, and gates.  The location, ventilation, and protection against fire hazard and personal injury

shall be subject to the approval of the chief. (D) The division of mineral resources management shall accept standard electrical practices

in regard to the underground electrical installations and operation of alternating

current equipment, but may augment the same to provide additional safeguards.  When exercising this authority, the division shall give due consideration to the

safety experience in regard to similar installations and the similar operation thereof

under similar conditions. (E) The mine foreperson shall have posted at the mine opening, and in all permanent substations

therein, a copy of instructions as to the method of resuscitation of persons suffering

from electric shock.  All persons working about such stations, or with electric machines, shall familiarize

themselves with such rules. No operator of a mine shall refuse or neglect to comply with this section.