Blue Chip Series explosion-proof motors

Marathon Electric, now a Regal Rexnord brand, builds three-phase NEMA frame explosion-proof induction motors under its Hazardous Duty and Blue Max Hazardous Duty names. They are designed for hazardous locations where flammable gases, vapours or combustible dusts may be present, carrying UL listing for Class I Division 1 gas groups and Class II dust groups, with temperature codes marked on the nameplate. Construction is cast iron with flame paths machined into frame, end brackets and conduit box, and the motors are totally enclosed fan cooled (EPFC) or non-ventilated (EPNV). An example is model U005A, a 5 hp, 1800 rpm, 184T frame motor for 230/460 V 60 Hz and 190/380 V 50 Hz supply; the Blue Max versions are inverter-duty for wide constant-torque speed ranges on VFDs. Motors below the 182T frame have been moved to the LEESON brand. Typical uses are pumps, fans, compressors and conveyors in petrochemical plants, refineries, grain handling, paint booths and wastewater facilities. ‘Blue Chip’ was Marathon’s name for premium-efficiency general-purpose motors, not an explosion-proof line.