Pennsylvania Code
Title 34 - LABOR AND INDUSTRY
Part I - Department of Labor and Industry
Chapter 29 - MECHANICAL APPARATUS-MISCELLANEOUS
Subchapter C - MECHANICAL POWER TRANSMISSION APPARATUS
RECOMMENDATIONS
Section 29.149 - Power control

(a) Among the methods used for power control are motor switches, friction clutches, belt shifters, and engine stops. The means for controlling power should be positive and should be so arranged as to permit operation from a point not more than 100 feet from any machine driven from the source of power in question. It is highly advisable to arrange the stations within 50 feet of any machine. There are cases, as for example in the steel industry, when a greater distance from the machine becomes necessary.

(b) It is advisable to mark the stop station with a mark easily distinguishable; green bands on posts and green circles on walls are recommended, together with a sign "Stop Station" or "Emergency Stop." A light of characteristic color should be added in shops where night work is carried on.

(c) Electrical safety devices should operate by the opening of a normally closed circuit. Any failure of the current or device will thus be indicated by the stopping of the prime mover. It is advisable to test such devices daily by shutting off the power at noon or night by such means.