WM. PRESTON LANE, JR., GOVERNOR. 1065

cable, purchased after the effective date of this Act, shall
be grounded effectively.

118. Circuit Breakers and Switches, (a) Fuses or
equivalent protective devices of the correct type and capac-
ity shall be installed on electric equipment to protect
against excessive overload. Wires or other conducting
materials shall not be used as a substitute for properly
designed fuses, and where circuit breakers are used, they
shall be maintained in proper operating condition and
adjusted so that equipment cannot be overloaded. Switches
and circuit breakers shall be installed so that they are
readily accessible and can be operated without danger of
contact with moving or live parts.

(b) Disconnecting switches shall be installed in all
main power circuits at the bottoms of shafts, boreholes,
and at other places where main power circuits enter the
mine.

Underground electric equipment and circuits shall be
provided with switches or other controls of safe design
and construction, they shall be installed in a safe manner.

(c) Power circuits shall be protected against short
circuit or excessive overload. Wires or other conducting
materials shall not be used as a substitute for properly
designed fuses; where circuit breakers are used they shall
be maintained in proper operating condition,

Dry wooden platforms, rubber mats, or other electrically
non-conductive material shall be kept in place at each
switchboard, power-control switch, and at stationary ma-
chinery where shock hazards exist.

119. Telephone Systems. Telephone service or equiva-
lent communication facilities shall be provided at the bot-
tom of each main shaft or slope and in all mines from the
surface to the working sections of the mine where the mine
workings are 1500 feet or more from the surface.

Telephone lines, other than cables, shall be carried on
insulators, installed on the opposite side from power or
trolley wires, and where they cross power or trolley wires,
they shall be insulated adequately. Telephone circuits on
the surface shall be protected by lightning arresters.

119A. Signal Systems. Signal wires shall be supported
on insulators and insulated properly where they cross
power lines.

Bare signal wires that are readily accessible to personal
contact shall not carry more than 30 volts. (This does not
apply to block-signal system).