|U.S. Department of
Mine Safety and Health Administration|
201 12th Street South, Suite 401
Arlington, VA 22202-5450
PROGRAM INFORMATION BULLETIN NO. P11-01
FROM: LINDA F. ZEILER
Acting Director of Technical Support
KEVIN G. STRICKLIN
Coal Mine Safety and Health
SUBJECT: Redesign of the Emergency Stop Circuits on Model BHAC Joy Mining
Machinery (formerly Stamler Corporation) Battery Coal Haulers
This Program Information Bulletin (PIB) applies to mine operators, miners' representatives, Mine Safety and Health Administration (MSHA) enforcement personnel and other interested parties.
The purpose of this PIB is to inform the mining community that MSHA has approved a safety upgrade to the emergency stop switch circuit on the Joy Battery Coal Hauler (Approval No. 18-A060011-0). Additionally, this PIB includes recommendations concerning operation of the emergency stop switch.
Joy Mining Machinery has designed and received MSHA approval for a safety upgrade to the emergency stop switch circuit on the Joy Battery Coal Hauler (Approval No. 18-A060011-0). The upgrade ensures against inadvertent movement of the machine when the emergency stop switch is activated by providing a second shutdown circuit that prevents the pump from restarting on release of the emergency stop switch.
MSHA recommends that mine operators:
- Remove the machine from service if any machine light stays on after hitting the emergency stop switch. This is an indication that the circuit breaker has not tripped and the machine is still energized.
- Verify the proper performance of the emergency stop switch as part of the pre-operation machine checks.
The second emergency stop circuit is designed and wired through the Programmable Logic Controller to ensure that the machine tram circuit is shut down and remains shut down when the emergency stop switch is activated. If the emergency stop switch is activated and any machine or display lights remain on, this indicates that the machine circuits remain energized and a problem exists. One of these problems could be failure of the circuit breaker to trip on activation of the emergency stop switch. Joy Mining has released a Service Bulletin (attached) that was distributed to all of its customers of equipment utilizing MSHA Approval No. 18-A060011-0. The Service Bulletin provides information about an upgrade kit and describes the wiring change to install the upgrade of the emergency stop switch circuit.
MSHA became aware of an incident where activation of the emergency stop switch on a Joy Hauler caused the machine to come to a stop, but did not deenergize the machine. It was noted that the lights were still on and when the emergency stop switch was released, the pump motor restarted, which released the brakes and enabled the machine to be trammed. This could have caused unintentional movement of the machine.
MSHA's authority for this PIB
The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. § 801 et seq.; 30 CFR §§ 75.523
This information bulletin may be viewed on the Internet by accessing MSHA's home page at (http://www.MSHA.gov) and then choosing Compliance Info and Program Information Bulletins.
MSHA contact persons for this bulletin
Technical Support, Approval and Certification Center
Kenneth Porter, (304) 547-2030
Coal Mine Safety and Health, Safety Division
John Arrington, (202) 693-9549
Program Policy Manual Holders
Underground Mine Operators