Variable Frequency Drives - NEMA VFD Enclosure Ratings
| NEMA Type |
Definition |
| 1 | General-purpose. For indoor use. Provides a degree of protection to personnel against hazardous parts and a degree of protection to internal parts of enclosure against solid foreign objects. |
| 2 | Drip-tight. Similar to Type 1 but with addition of drip shields to add a degree of protection to internal parts of enclosure with respect to harmful effects of dripping water. |
| 3 | Weather-resistant. Provides a degree of protection against falling rain and ice formation. Provides a degree of protection to internal parts of enclosure against solid foreign objects, rain, sleet, snow, and external icing. |
| 3R | Intended for outdoor use. Provides a degree of protection against falling rain and ice formation. Provides a degree of protection to internal parts of enclosure against solid foreign objects, rain, sleet, snow, and external icing. |
| 4 | Watertight (weatherproof). Must exclude at least 65 GPM of water from 1-in. nozzle delivered from a distance not less than 10 ft for 5 min. Provides a degree of protection with respect to harmful effects on the equipment due to the ingress of water such as rain, sleet, snow, splashing water, and hose directed water. |
| 4X | Watertight (weatherproof). Must exclude at least 65 GPM of water from 1-in. nozzle delivered from a distance not less than 10 ft for 5 min. Provides a degree of protection with respect to harmful effects on the equipment due to the ingress of water such as rain, sleet, snow, splashing water, and hose directed water. Also provides an additional level of protection against corrosion |
| 5 | Dust-tight. Provide a degree of protection of the equipment inside enclosure against solid foreign objects such as falling dirt and settling airborne dust, lint, fibers, and flyings; and to provide a degree of protection with respect to harmful effects on the equipment due to the water such as dripping and light splashing. |
| 6 | Submersible. Design depends on specified conditions of pressure and time; provides a degree of protection with respect to harmful effects on the equipment due water such as hose directed water and the entry of water during prolonged submersion at a limited depth. |
| 12 | General-purpose. Intended for indoor use, provides a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects such as falling dirt and circulating dust, lint, fibers, and flyings; and to provide a degree of protection with respect to harmful effects on the equipment due to water such as dripping and light splashing. |
| 13 | General-purpose. Provides a degree of protection of the equipment inside the enclosure against solid foreign objects such as falling dirt and circulating dust, lint, fibers, and flyings; provides a degree of protection with respect to harmful effects on the equipment due to water such as dripping and light splashing; and to provide a degree of protection against the spraying, splashing, and seepage of oil and non-corrosive coolants. |
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