An analysis was performed to determine whether an increased shock hazard occurs with 2400-V continuous-miner trailing cables, as compared with those used with existing low-and medium-voltage systems. (It should be noted that the Code of Federal Regulations defines low, medium, and high voltages for mine power systems as 0-660, 661-1000, and > 1000 V, respectively.) The study assumed that the Mine Safety and Health Administration's Proposed Rule for High-Voltage Continuous Mining Machines was implemented with the exception of the special cable-handling requirements. Two major differences between the high-voltage proposed rule and existing low-and medium-voltage regulations that are relevant to this study deal with ground-fault protection and include the following: 1) The maximum ground-fault current of the 2400-V system must be limited to 0.5 A, while low-and medium-voltage systems typically use a 15-A limit; and 2) the maximum ground-fault pickup of the 2400-V system must be set at 0.125 A with a maximum time delay of 0.05 s, whereas low-and medium-voltage systems require an instantaneous pickup set at, or below, 40% of the maximum ground-fault current (6 A for 15-A systems). Results of the study show that 2400-V trailing cables, in conjunction with the stricter ground-fault protection requirements and enhanced cable construction, provide a higher level of safety compared with trailing cables used on low-and medium-voltage continuous miners.
|Number of pages||8|
|Journal||IEEE Transactions on Industry Applications|
|State||Published - Mar 2012|
Bibliographical noteFunding Information:
Manuscript received January 15, 2008; accepted April 22, 2010. Date of publication January 12, 2012; date of current version March 21, 2012. Paper PID-11-03, presented at the 2007 Industry Applications Society Annual Meeting, New Orleans, LA, September 23–27, and approved for publication in the IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS by the Mining Industry Committee of the IEEE Industry Applications Society. This work was supported by Joy Mining Machinery.
- Mine electrical safety
- mine power systems
- mine trailing cables
ASJC Scopus subject areas
- Control and Systems Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering