Program Policy Manual - VOLUME V - Mine Safety and Health ...
Program Policy Manual - VOLUME V - Mine Safety and Health ...
Program Policy Manual - VOLUME V - Mine Safety and Health ...
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MSHA PROGRAM POLICY MANUAL <strong>VOLUME</strong> V<br />
Where track is used as a power conductor, efficient connections<br />
require that:<br />
1. Both rails of main-line tracks shall be welded or bonded<br />
at every joint, <strong>and</strong> cross bonds shall be installed at<br />
intervals of not more than 200 feet. If the rails are<br />
paralleled with a feeder circuit of like polarity, such<br />
parallel feeder shall be bonded to the track rails at<br />
intervals of not more than 1,000 feet.<br />
2. At least one rail on secondary track-haulage rails shall<br />
be welded or bonded at every joint, <strong>and</strong> cross bonds shall<br />
be installed at intervals of not more than 200 feet.<br />
3. Track switches in entries shall be well bonded.<br />
4. In rooms where electric equipment is dependent upon the<br />
room track rails as a power conductor, rail joints shall<br />
be secured by means of fish plates, angle bars, or the<br />
equivalent, <strong>and</strong> at least one rail shall be bonded at each<br />
joint.<br />
Visible arcing or heating at rail joints indicates poor<br />
connections or poor bonding.<br />
Main-line track is interpreted to be track used to transport coal<br />
outby the junction of two or more coal-producing sections. All<br />
other track is considered to be secondary track <strong>and</strong> includes<br />
track that is used to transport miners <strong>and</strong> material or coal from<br />
a single coal-producing section. Both rails of secondary track<br />
may need to be bonded or welded at each joint if the additional<br />
current-carrying capacity is needed for compliance with Section<br />
75.1001.<br />
Bonding as used herein means a connection used to insure the<br />
required electrical conductivity between the rails. The<br />
connection may be obtained mechanically, as with a wedge or by<br />
welding the bonds on the rails.<br />
75.515 Cable Fittings; Suitability<br />
This Section requires fittings of such design as to prevent<br />
chafing of cable or wire insulation that would expose or<br />
accidentally ground the conductors at points where they enter the<br />
compartment walls of switch boxes, starters, motors, cable<br />
couplers, etc. Insulated wires passing through walls of metal<br />
enclosures shall be protected against damage to the insulation by<br />
February 2003 (Release V-33) 63
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