[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR18.24]

[Page 95]
 
                       TITLE 30--MINERAL RESOURCES
 
  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
 
PART 18--ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES--Table of Contents
 
             Subpart B--Construction and Design Requirements
 
Sec. 18.24  Electrical clearances.

    Minimum clearances between uninsulated electrical conductor 
surfaces, or between uninsulated conductor surfaces and grounded metal 
surfaces, within the enclosure shall be as follows:

             Minimum Clearances Between Uninsulated Surfaces
------------------------------------------------------------------------
                                                    Clearances (inches)
                                                 -----------------------
                                                               Phase-to-
          Phase-to-Phase Voltage (rms)             Phase-to-   Ground or
                                                     Phase      Control
                                                                Circuit
------------------------------------------------------------------------
0 to 250........................................        0.25        0.25
251 to 600......................................        0.28        0.25
601 to 1000.....................................        0.61        0.25
1001 to 2400....................................        1.4         0.6
2401 to 4160....................................        3.0         1.4
------------------------------------------------------------------------


[57 FR 61209, Dec. 23, 1992]