Distribution Boxes BXM(D)51 Series Explosion-proof Illumination (Power) Distribution Boxes (Ex d e 11B) Explosion protection to -CENELEC -IEC -NEC Can be used in Zone 1 and Zone 2 Zone 21 and Zone 22 Class l, Zone 1 and Zone 2 Class l, Division 2, Groups C, D Enclosure for. Distribution Boxes BXM(D)51 Series Explosion-proof Illumination (Power) Distribution Boxes (Ex d e 11B) Explosion protection to -CENELEC -IEC -NEC Can be used in Zone 1 and Zone 2 Zone 21 and Zone 22 Class l, Zone 1 and Zone 2 Class l, Division 2, Groups C, D Enclosure for. Distribution Boxes BXM(D)51 Series Explosion-proof Illumination (Power) Distribution Boxes (Ex d e 11B) Explosion protection to -CENELEC -IEC -NEC Can be used in Zone 1 and Zone 2 Zone 21 and Zone 22 Class l, Zone 1 and Zone 2 Class l, Division 2, Groups C, D Enclosure for modular combination (Ex d. BX51 Standard Explosion-Proof Distribution Box delivers safe power control and distribution in explosive-prone environments. The BXM, BXD, and BXJ explosion-proof distribution boxes are engineered for the safe operation and control of specialized equipment in hazardous environments. When electrical systems lack proper protection, the results may include. Scope of application 1, Zone 1, Zone 2 explosive gas environment. Dust hazardous sites in areas 20, 21 and 22.