NEMA Motor Enclosure Types

Enclosure type definitions, environmental ratings, and typical application areas per NEMA MG-1.

NEMA Enclosures

NEMA Motor Enclosure Types - Selection Reference · Source: NEMA MG 1-2021 Section IV Part 5 (Classification); NEC Article 500/502/503; IEC 60034-5 (IP equivalents).

NEMA Type	Description	Environment / Application	IEC IP Equivalent	Typical Use
ODP	Open Drip-Proof	Clean, indoor, dry locations. Ventilation openings protected against drips from above.	IP22	Motor rooms, indoor pumps in clean service
WPI	Weather-Protected I	Outdoor or dusty indoor; ventilation openings minimized to limit entry of rain/snow/dust.	IP23	Outdoor utility motors with shelter
WPII	Weather-Protected II	Outdoor; ventilation labyrinth provides 3 abrupt 90-deg turns and 600 fpm max air velocity.	IP24 (approx)	Large outdoor utility motors
TEFC	Totally Enclosed Fan-Cooled	Dust-tight enclosure; external fan on shaft for cooling. Most common industrial.	IP54/IP55	Chemical plant, refinery general service motors
TEAO	Totally Enclosed Air-Over	Cooled by airstream from driven equipment (e.g., fan motor in fan airstream).	IP55	Fan-cooled fan motors, cooling tower fans
TENV	Totally Enclosed Non-Ventilated	No cooling fan; heat rejected through frame surface only. Lower HP only.	IP54	Small fractional HP in clean enclosed spaces
TEWAC	Totally Enclosed Water-Air-Cooled	Integral water-to-air heat exchanger; internal air circulated by fan.	IP54/IP55	Large motors (>1500 HP) where cooling water available
TEAAC	Totally Enclosed Air-Air-Cooled	Air-to-air tube-type heat exchanger on top; internal and external fans.	IP54/IP55	Large motors in hot or dirty environments
XP	Explosion-Proof (Class I Div 1/2)	Enclosure contains internal explosion; flame paths cool escaping gas below ignition.	Ex d (IECEx)	Gas/vapor hazardous areas - refinery process units
DP (Dust-Ignition-Proof)	Dust-Ignition-Proof (Class II)	Excludes combustible dust; external surface limited below dust ignition temp.	Ex tD / Ex t	Grain handling, coal, sulfur, metal dust
TEPV	TE Pipe-Ventilated	Cooling air ducted in from clean source via pipe; dust/chemical exclusion.	IP55 (with duct)	Motors in contaminated atmospheres with remote clean-air source
Submersible	Submersible (IP68 equiv)	Fully sealed; designed for continuous submerged operation.	IP68	Submersible well pumps, sewage pumps
Selection Heuristics:
Default for industrial/process service: TEFC with appropriate area classification (Div 1 = XP, Div 2 = TEFC acceptable if not an ignition source).
For Class I Div 2 IEC Zone 2 service, IEC Ex nA (non-sparking) = NEMA equivalent is TEFC with temperature code marking.
NEC 501 requires XP motors in Class I Division 1 locations.
Temperature code (T1-T6) must be less than or equal to autoignition temp of gas/vapor at service conditions.
IP rating: first digit = solids, second = liquids. IP54 = dust-protected + splash-resistant; IP55 = dust-protected + low-pressure jets.
Offshore / marine: specify additional epoxy coating per IEEE 841 or equivalent severe duty spec.

Source: NEMA_Motor_Enclosure_Types_v1.xlsx

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