4VAC25-40-5120. Installation of main fans.
Main fans shall be:
1. Installed on the surface;
2. Powered electrically from a circuit independent of the mine power circuit. Internal combustion engines shall be used only for standby power or where electrical power is not available;
3. Installed in fireproof housing provided with fireproof air ducts;
4. Offset not less than 15 feet from the nearest side of the mine opening and equipped with ample means of pressure relief unless:
a. The opening is not in direct line with forces which would come out of the mine should an explosion occur; and
b. Another opening not less than 15 feet nor more than 100 feet from the fan opening is equipped with a weak wall stopping or explosion doors in direct line with the forces which would come out of the mine should an explosion occur;
5. Installed to permit prompt reversal of airflow; and
6. Attended constantly or provided with automatic devices to give alarm when the fans slow down to stop. Such devices shall be placed so they will be seen or heard by responsible persons.
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 § 15.236, eff. July 19, 1989; amended, Virginia Register Volume 14, Issue 17, eff. July 1, 1998.