Pennsylvania Code
Title 34 - LABOR AND INDUSTRY
Part I - Department of Labor and Industry
Chapter 43 - TUNNEL CONSTRUCTION AND COMPRESSED AIR WORK
Subchapter A - TUNNEL CONSTRUCTION AND WORK IN COMPRESSED AIR
TUNNEL CONSTRUCTION
Section 43.30 - Electrical equipment

(a) Installation. No person shall, without authority, install or handle electric wires, lights, conductors or electrical apparatus of any kind, or enter an electrical machine room or underground station.

(b) Instructions. No person shall be allowed to work with electrically driven apparatus, unless he is previously instructed by a competent person and duly authorized by the tunnel superintendent or tunnel foreman.

(c) Shock. Instructions for the disengaging of persons from contact with live wires and the resuscitation of persons suffering from electric shock shall be posted at the entrance to the tunnel, in every generating station and substation, and in all underground electric stations. All employes working with electrical apparatus shall be required by the tunnel superintendent to familiarize themselves with the instructions of this section.

(d) Grounding. The frames and bed plates of generators, transformers, compensators, rheostats and motors installed underground shall be effectively grounded. All metallic coverings, armoring of cables (other than trailing cables), and the neutral wire of three-wire systems shall be grounded.

(e) Underground voltage. When electrical systems are installed, no higher voltage than low voltage shall be used underground, except for transmission or for application to transformers, motors, generators or other apparatus in which the whole of the medium or high voltage apparatus is stationary.

(f) Switchboard construction. Switchboards shall consist of a substantial framework of iron pipes, angle irons or bar iron, on which shall be mounted a panel or panels of incombustible nonabsorbent material that is mechanically strong and has insulating qualities suitable for the voltage at which it is used.

(g) Switchboard panels. The panels of insulating material may be omitted, if each piece of equipment carried on the switchboard is provided with an individual base of insulating material of the character specified for the panels. The material shall be of adequate dimensions, or have its current-carrying parts mounted on similar insulating self-contained in the equipment, which shall be especially designed for mounting on iron, pipe, angle iron or bar iron frameworks.

(h) Danger signals. All medium and high voltage machines and apparatus shall be conspicuously marked with the word "danger" and shall be properly illuminated when in circuit.