Article 7. Electricity
4VAC25-40-3890. Bare wires and cables.
Wires and cables not encased in armor shall be supported by well-installed insulators and shall not touch combustible materials, roof, or ribs; however, this requirement shall not apply to ground wires, grounded power conductors, and trailing cables.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.113, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-3900. Metal pipelines.
Metal pipelines 1,000 feet or more in length along haulage roads where grounded return circuits are used shall be bonded to the return at the ends and at intervals not exceeding 500 feet.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.114, eff. July 19, 1989.
4VAC25-40-3910. Insulation of power lines.
Power lines shall be well separated or insulated from waterlines, telephone lines, and air lines.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.115, eff. July 19, 1989.
4VAC25-40-3920. Fastening power cables.
Power cables in shafts and boreholes shall be fastened securely in such manner as to prevent undue strain on the sheath, insulation, or conductors.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.116, eff. July 19, 1989.
4VAC25-40-3930. Disconnecting switches.
Disconnecting switches that can be opened safely under load shall be provided underground at all primary power circuits near shafts, levels, and boreholes. Disconnecting switches shall be installed underground in all main power circuits within approximately 500 feet of the bottoms of shafts and boreholes, and at other places where main power circuits enter the mine.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.117, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-3940. Transformer stations.
Transformer stations shall be enclosed to prevent persons from unintentionally or inadvertently contacting energized parts.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.118, eff. July 19, 1989.
4VAC25-40-3950. Trolley feeder wires.
Trolley and trolley feeder wires shall be installed opposite the clearance side of haulageways.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.119, eff. July 19, 1989.
4VAC25-40-3955. Fire precautions in transportation of mining equipment.
A. Prior to moving or transporting any unit of off-track mining equipment in areas of the active workings where energized trolley wires or trolley feeder wires are present:
1. The unit of equipment shall be examined by a certified person to ensure that accumulation of oil, grease, and other combustible materials have been removed from such unit of equipment; and
2. A qualified person shall examine the trolley wires, trolley feeder wires, and the associated automatic circuit interrupting devices to ensure that proper short circuit protection exists.
B. A record shall be kept of the examinations and shall be made available, upon request, to the director.
C. Off-track mining equipment shall be moved or transported in areas of the active workings where energized trolley wires or trolley feeder wires are present only under the direct supervision of a certified person who shall be physically present at all times during moving or transporting such equipment.
D. The frames of off-track mining equipment being moved or transported in accordance with this section shall be covered on the top and on the trolley wire side with fire-resistant material, where appropriate, as determined by the director.
E. Electrical contact shall be maintained between the mine track and the frames of off-track mining equipment being moved in-track and trolley entries, except that rubber-tired equipment need not be grounded to a transporting vehicle if no metal part of such rubber-tired equipment can come into contact with the transporting vehicle.
F. To avoid accidental contact with power lines, the equipment being transported or trammed shall be insulated or assemblage removed, if necessary, if the clearance to the power lines is six inches or less.
G. Sufficient prior notice shall be given the department so that a mine inspector may travel the route of the move before the actual move is made, if he deems it necessary.
H. A minimum vertical clearance of 12 inches shall be maintained between the farthest projection of the unit of equipment which is being moved and the energized trolley wires or trolley feeder wires at all times during the movement or transportation of such equipment. If the height of the seam of minerals does not permit 12 inches of vertical clearance to be so maintained, the following additional precautions shall be taken:
1. Electric power shall be supplied to the trolley wires or trolley feeder wires only from out by the unit of equipment being moved or transported. Where direct current electric power is used and such electric power can be supplied only from the equipment being moved or transported, power may be supplied from such equipment if a miner with the means to cut off the power, and in direct communication with persons actually engaged in the moving or transporting operation, is stationed out by the equipment being moved;
2. The settings of automatic circuit interrupting devices used to provide short circuit protection for the trolley circuit shall be reduced to not more than one-half of the maximum current that could flow if the equipment being moved or transported were to come into contact with the trolley wire or trolley feeder wire;
3. At all times the unit of equipment is being moved or transported, a miner shall be stationed at the first automatic circuit breaker out by the equipment being moved. Such miner shall be in direct communication with persons actually engaged in the moving or transporting operation and capable of communicating with the authorized person on the surface required to be on duty;
4. Where trolley phones are utilized to satisfy the requirements of subsection C of this section, telephones or other equivalent two-way communication devices that can readily be connected with the mine communication system shall be carried by the miner stationed at the first automatic circuit breaker out by the equipment being moved and by a miner actually engaged in the moving or transporting operation; and
5. No person shall be permitted to be in by the unit of equipment being moved or transported, in the ventilating current of air that is passing over such equipment, except those persons directly engaged in moving such equipment. The provisions of this section shall not apply to units of mining equipment that are transported in mine cars, provided that no part of the equipment extends above or over the sides of the mine car.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-3958. Use of track as electrical power conductor.
The following standards shall apply where track is used as a power conductor:
1. Both rails of main line tracks shall be welded or bonded at every joint, and cross bonds shall be installed at intervals of not more than 200 feet. If the rails are paralleled with a feeder circuit of like polarity, such paralleled feeder shall be bonded to the track rails at intervals of not more than 1,000 feet.
2. At least one rail on secondary track haulage roads shall be welded or bonded at every joint, and cross bonds shall be installed at intervals of not more than 200 feet.
3. Track switches on entries shall be well-bonded.
4. Rails shall not be used as power conductors in rooms.
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Historical Notes
Derived from Virginia Register Volume 14, Issue 17, eff. July 1, 1998.
4VAC25-40-3960. Splices in trailing cables.
Not more than five splices shall be made in any trailing cable unless they are vulcanized.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.120, eff. July 19, 1989.
4VAC25-40-3970. Machines not using cable reels.
On machines not using cable reels, no splices shall be present in the first 25 feet of trailing cable adjacent to the equipment.
Statutory Authority
§§ 45.1-161.3 and 45.1-161.294 of the Code of Virginia.
Historical Notes
Derived from VR480-05-1.2 § 15.121, eff. July 19, 1989.