| Flameproof Box-Design Motor | Gas Zones 1 and 2; Equipment Groups IIA, IIB, and selected IIC applications | Ex db or Ex db eb, depending on the terminal-box and motor construction | Approximately 0.12–315 kW for low- and medium-voltage industrial duties | 230/400 V or 400/690 V at 50 Hz; 460 V at 60 Hz is also common | IE3 is widely specified; IE4 may be selected where lifecycle energy savings justify the higher initial cost | Cast or fabricated enclosure; normally TEFC with IC411 cooling | T3 or T4 is common; T5 and T6 require lower permissible surface temperatures | Pumps, fans, compressors, conveyors, mixers, and general process machinery | Verify gas group, maximum surface temperature, starting current, shaft load, cable-entry certification, and flame-path requirements |
| Increased-Safety Box-Design Motor | Gas Zones 1 and 2 where ignition sources must be prevented during normal operation | Ex eb; used for equipment designed to avoid arcs, sparks, and excessive temperatures | Approximately 0.12–250 kW, subject to the certified design and starting method | Typically 230/400 V or 400/690 V, 50 Hz; compatible with direct-on-line, star-delta, or soft-start systems when certified | IE3 or IE4, depending on frame size, load profile, and applicable local requirements | TEFC, IC411 cooling; robust terminal enclosure with certified increased clearances | T3 or T4 in many process installations | Continuous-duty pumps, air-handling equipment, belt conveyors, and low-to-medium inertia loads | Confirm starting behavior and locked-rotor duration because increased-safety designs have strict thermal limits |
| Dust-Protected Box-Design Motor | Dust Zones 21 and 22; combustible dust environments | Ex tb or Ex tc with protection by enclosure | Approximately 0.12–315 kW | 230/400 V or 400/690 V at 50 Hz; 460 V at 60 Hz is available in many configurations | IE3 is a practical baseline; IE4 is beneficial for high annual operating hours | Dust-tight enclosure, typically IP65 or IP66; IC411 cooling is common | Surface-temperature limit is selected according to the dust layer or dust cloud ignition risk | Grain handling, flour processing, wood processing, chemical powders, and bulk-material conveyors | Specify dust type, permitted surface temperature, dust-layer thickness assumptions, ingress protection, and cleaning method |
| Non-Sparking Box-Design Motor | Gas Zone 2 only, where an explosive gas atmosphere is not expected during normal operation | Ex ec | Approximately 0.12–315 kW | Low-voltage three-phase supply, commonly 400 V at 50 Hz or 460 V at 60 Hz | IE3 or IE4 for continuous-duty operation | TEFC, IC411; IP55 to IP66 depending on the installation environment | T3 or T4 is frequently selected | Ventilation systems, utility pumps, packaged skids, and auxiliary plant equipment | Not normally suitable for Zone 1; confirm the zone classification and fault conditions before selection |
| Pressurized or Purged Box-Design Motor | Selected Zone 1 or Zone 2 installations where a protected internal atmosphere is maintained | Ex pxb, Ex pzc, or another certified pressurization level | Approximately 15–1,000 kW, with larger ratings possible for engineered systems | Low- or medium-voltage supply; voltage and frequency depend on the driven equipment | IE3 or IE4 for standard induction designs; efficiency must be evaluated with the purge system included | Enclosed motor with purge-control equipment; cooling may be IC411 or a separately ventilated arrangement | Determined by the certified motor design and internal component temperatures | Large compressors, high-capacity fans, gas-processing equipment, and specialized process trains | Provide clean instrument air or inert gas, reliable pressure monitoring, purge sequencing, alarms, and shutdown interlocks |
| Ex Motor for Variable-Speed Drive Operation | Gas or dust hazardous areas, provided the complete motor-drive system is certified for the intended zone | Commonly Ex db, Ex eb, Ex ec, or Ex tb with inverter-duty approval | Approximately 0.75–500 kW; usable speed range depends on cooling and certification | Motor voltage typically 400/690 V; drive output frequency may range from about 5–60 Hz or wider with approval | IE3 or IE4; system efficiency should include motor, drive, filters, and auxiliary cooling | TEFC at base speed; separately driven fan or reduced-load operation may be required at low speed | Must be verified across the complete speed and load range | Variable-flow pumps, process fans, extruders, conveyors, and controlled-torque machinery | Check bearing-current protection, dv/dt filtering, thermal sensors, minimum cooling speed, cable length, and drive certification |
| Brake Box-Design Ex Motor | Gas Zones 1 and 2 or dust Zones 21 and 22, depending on the brake certification | Motor and brake may use different certified protection concepts | Approximately 0.12–90 kW | Typically 230/400 V or 400/690 V at 50 Hz; brake voltage commonly requires a separate certified circuit | IE3 is common; efficiency classification may exclude the brake assembly | TEFC motor with an enclosed spring-applied, electrically released brake | Usually T3 or T4, subject to brake heat generation and duty cycle | Hoists, cranes, inclined conveyors, positioning systems, and emergency-stop machinery | Confirm stopping time, brake torque, switching frequency, mechanical holding load, thermal duty, and manual-release requirements |
| Low-Temperature Ex Box-Design Motor | Outdoor or refrigerated hazardous locations with ambient temperatures below standard industrial limits | Protection concept selected according to the gas or dust zone; low-temperature materials and seals are added | Approximately 0.12–315 kW | Commonly 400 V at 50 Hz or 460 V at 60 Hz; starting performance must be checked at minimum temperature | IE3 or IE4, with attention to lubricant viscosity and reduced-temperature losses | TEFC, IC411; low-temperature bearings, grease, elastomers, and space heaters may be required | Based on hazardous-area classification and the lowest ambient operating temperature | LNG support systems, cold-storage process areas, outdoor terminals, and arctic installations | Specify minimum ambient temperature, condensation risk, heater control, startup interval, cable flexibility, and enclosure material |
| High-Temperature Ex Box-Design Motor | Hazardous areas with elevated ambient temperature or nearby hot process equipment | Certified Ex protection concept with derating for the selected ambient temperature | Approximately 0.12–315 kW before application-specific derating | Typically 400 V at 50 Hz or 460 V at 60 Hz; current and thermal limits must be recalculated | IE3 or IE4, subject to winding temperature and cooling limitations | TEFC, IC411, or separately ventilated cooling for demanding thermal conditions | Often T3 or T4; maximum ambient temperature may be 50 °C, 55 °C, or higher only when specifically certified | Refineries, furnaces, hot-air systems, chemical plants, and high-temperature process lines | Apply certified derating, verify bearing life, inspect ventilation paths, and avoid relying on standard nameplate output |