Illustrating the Luminaire Comparison Method

The Mine Safety and Health Administration (MSHA) enforces underground coal mining lighting regulations in the United States and issues approvals for electrical devices and machines. Companies submit standard test and evaluation (ST& E) documentation to MSHA when seeking approval on a machine-mounted lighting system. Subsequent machine modifications, such as changing the type of light lamp from incandescent to light-emitting diode (LED), will require an update via the revised approval modification program (RAMP). Older incandescent and fluorescent lamps are being replaced by LED technology which has many advantages. Today, thousands of obsolete compact fluorescent lamps are used in underground coal mines. Replacing these with LED lamps requires RAMP documentation for each ST& E. This could require MSHA to review virtually thousands of RAMPS that would require an exorbitant amount of resources and would create backlogs that would take MSHA potentially years to process. This problem is addressed by the luminaire comparison method (LCM) that determines if the luminous intensity from a luminaire with a replacement lamp meets or exceeds the luminous intensity of the luminaire with a legacy lamp. If it does, then the replacement lamp is determined as equivalent and can be used as a replacement. One RAMP can then replace multiple RAMPs that would be required without the LCM. One company estimates over 700,000 USD in savings; another company has saved about 200,000 USD using the LCM. It is projected that the LCM will save millions of dollars. This article provides several examples to illustrate the LCM.