Interactive Tool
NEMA Rating Selector
Not sure what NEMA rating you need? Answer 2–3 questions about your installation environment and we'll recommend the right rating — with examples and VoltAire models that match.
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Complete Reference
All NEMA Enclosure Ratings
The full list of NEMA enclosure ratings with what each protects against and where they're typically used.
| Rating | Protection | Typical Use |
|---|---|---|
| NEMA 1 | Indoor general purpose. Protection against falling dirt only. | Clean indoor commercial |
| NEMA 2 | Indoor drip-tight. Protection against limited dripping water. | Indoor with occasional drips |
| NEMA 3 | Outdoor weather-resistant. Wind, rain, sleet, ice. NOT dust-tight. | Outdoor utility (rare) |
| NEMA 3R | Outdoor rain/snow/sleet resistant. NOT dust-tight. | Outdoor service equipment |
| NEMA 3S | Like 3 but with external mechanism operable when iced. | Outdoor with ice loading |
| NEMA 4 | Watertight, dust-tight. Resists hose-directed water. | Outdoor industrial / washdown |
| NEMA 4X | Like NEMA 4 PLUS corrosion-resistant materials. | Coastal, chemical, food & beverage |
| NEMA 5 | Indoor dust-tight (rarely specified anymore — superseded by 12). | Indoor industrial (legacy) |
| NEMA 6 / 6P | Submersible (occasional vs prolonged). | Underground/submerged use |
| NEMA 7 | Indoor hazardous Class I Div 1 (explosive gas). | Refineries, chemical (indoor haz) |
| NEMA 8 | Hazardous Class I Div 1, oil-immersed contacts. | Hazardous mining, processing |
| NEMA 9 | Hazardous Class II Div 1 (combustible dust). | Grain elevators, flour mills |
| NEMA 12 | Indoor industrial. Dust-tight, drip-tight (no hose spray). | Standard factory/manufacturing |
| NEMA 13 | Like 12 but adds resistance to oil and coolant spray. | CNC, machine tools |
All VoltAire enclosure air conditioners and heat exchangers are NEMA 4 rated as standard; NEMA 4X (304 stainless steel) is available as an option on all models.
FAQ
Frequently Asked Questions
What is the difference between NEMA 4 and NEMA 4X?
NEMA 4 and NEMA 4X both protect against the same environmental conditions (windblown dust, rain, splashing water, and hose-directed water). The difference is that NEMA 4X requires corrosion-resistant materials (typically 304 or 316 stainless steel) for use in coastal, chemical, and food/beverage processing environments. NEMA 4 is acceptable for general outdoor use; NEMA 4X is required where corrosion is a concern.
Do I really need NEMA 4X if my enclosure is just outside?
For most outdoor industrial sites away from saltwater and not exposed to chemicals, NEMA 4 is sufficient. NEMA 4X becomes necessary within approximately 1 mile of saltwater (coastal cell towers, marina equipment), in chemical processing facilities, in food/beverage facilities using caustic CIP washdowns, in pulp and paper mills, and in wastewater treatment plants near chlorination systems.
Is NEMA 12 enough for my factory floor?
NEMA 12 is appropriate for most indoor industrial environments where dust, falling dirt, and dripping non-corrosive liquids are the main concerns. If your facility uses hose-directed water for cleaning, or if you have chemical exposure, you need NEMA 4 or 4X. All VoltAire enclosure air conditioners exceed NEMA 12 requirements (they're NEMA 4 rated as standard), so they're always safe for NEMA 12 applications.
What about IP ratings? How do they relate to NEMA?
NEMA and IP (Ingress Protection) are both enclosure rating systems but use different methodologies. There is no exact equivalence, but rough equivalents include: NEMA 1 ≈ IP10, NEMA 12 ≈ IP52, NEMA 4 ≈ IP66, NEMA 4X ≈ IP66 (with corrosion resistance), NEMA 6P ≈ IP67. NEMA tests are slightly more demanding in some areas. Many manufacturers specify both ratings for international compatibility.
Can a NEMA 4 unit be used in a NEMA 12 application?
Yes, always. NEMA 4 (outdoor watertight) exceeds NEMA 12 (indoor dust-tight, drip-tight) requirements. Conversely, NEMA 12 is NOT sufficient for NEMA 4 applications because it's not rated for direct hose-down water spray. Engineers often spec NEMA 4 for indoor applications when there's any uncertainty about future water exposure or potential cleaning practices.
What NEMA rating do VoltAire enclosure air conditioners have?
All VoltAire enclosure air conditioners and heat exchangers are NEMA 4 rated as standard, in the Off White (Hentzen P2234WPC-2) finish. NEMA 4X is available as an option with 304 stainless steel construction. This means VoltAire units are suitable for NEMA 1, 2, 3R, 4, 5, 12, and 13 applications without modification, and for NEMA 4X applications with the stainless steel option.
Need Help Choosing?
Our team has been specifying enclosure cooling for industrial, telecom, and outdoor applications since 2018. Tell us about your installation and we'll recommend the right rating and model.