U.S. Department of Labor

Mine Safety and Health Administration 4015 Wilson Boulevard Arlington, Virginia 22203-1984

ISSUE DATE: May 16, 2002

PROGRAM INFORMATION BULLETIN NO. P02-2

FROM:           MARK E. SKILES
                        Director of Technical Support

SUBJECT:     Modifications to MSHA Approved Explosion-Proof Motors to
                      Incorporate the Use of Pipe Nipple Extensions to Mount Conduit Boxes

Who needs this information?
Mine equipment manufacturers, underground coal mine operators, underground gassy metal/nonmetal mine operators, mine equipment rebuild facilities, and Mine Safety and Health Administration (MSHA) enforcement personnel should have this information.

Why is MSHA issuing this bulletin?
This bulletin informs manufacturers of mining equipment, repair shop facilities and underground mine operators of the importance of formally notifying MSHA of proposed changes to MSHA approved motors for use on permissible mining equipment. Title 30 CFR, Part 7 and Part 18 require that modifications to MSHA approved motors be submitted to MSHA for approval.

Many MSHA approved motors have a threaded pipe mounted between the motor housing and the conduit box. Typically, an epoxy material is applied in the pipe, which serves as an isolation barrier between the motor housing and the conduit box. Testing of these motors was performed in accordance with the requirements of 30 CFR, Part 7 or Part 18. Removal of the isolation barrier may adversely affect the explosion-proof integrity of the motor, resulting in an unsafe condition. The barrier must be maintained in accordance with the drawings and specifications on file at MSHA in order for the approval to be valid. Without a valid approval, such an item cannot be used in an underground mine where permissible electrical equipment is required. Changes in the design of an MSHA approved motor by parties other than the motor manufacturer or the approval holder are not permitted.

What is the background for this bulletin?
It has come to the attention of MSHA that manufacturers of mine equipment and mining products and underground mine operators have modified MSHA approved explosion-proof motors to accept the use of pipe nipple extensions to mount the conduit boxes. The modifications to these explosion-proof motors were not always properly documented to MSHA and may not have been evaluated or tested as part of the motor approval process.

What is MSHA's authority for this Program Information Bulletin?
The Federal Mine Safety Act of 1977; 30 C.F.R Part 7 and Part 18.

Is this Program Information Bulletin on the Internet?
This information bulletin may be viewed on the World Wide Web by accessing the MSHA home page (http://www.msha.gov) and then choosing "Statutory and Regulatory Information" and "Compliance Assistance Information."

Who is the MSHA contact person for this bulletin?
Technical Support, Approval and Certification Center
Kenneth J. Porter, (304) 547-2030
E-mail: Porter.Kenneth@dol.gov

Who will receive this bulletin?
MSHA Program Policy Manual Holders
Miners' Representatives
Underground Mine Operators
Manufacturers of Mine Equipment and Mining Products
Repair Shop Facilities
Special Interest Groups