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NEMA 4 Rating 

Definition: Enclosure is intended for indoor use primarily to provide a degree of protection against windblown dust and rain, splashing water, and hose directed water; undamaged by ice which forms on the enclosure or cabinet. 

Applications: NEMA 4 industrial enclosures can be used in numerous industrial applications whereby water hose spray wash-down occurs or where machine tool cutter coolant is used and sprayed. The NEMA 4 enclosure also serves well in applications where there is possibly dripping water in a building. The enclosure has a drip edge (gutter) to collect water near the enclosure seals. A NEMA 4 enclosure must have quality seal gasket to prevent water ingress and the door is typically clamped for maximum sealing. Nemaco offers NEMA 4 enclosures with continuous hinges, floor mounting feet and optional padlock hasps. Nemaco offers enclosures in full range of junctions to two-door floor mount cabinets. 

NEMA 4X Rating 

Definition: Enclosure is intended for indoor or outdoor use primarily to provide a degree of protection against corrosion, windblown dust and rain, splashing water, and hose directed water; undamaged by ice which forms on the enclosure. 

Applications: The key difference is that NEMA 4X enclosures are primarily fabricated from corrosion resistant materials (i.e., 304 / 316 stainless steel, fiberglass or plastics). Applications where corrosive materials (for example saltwater) and acid / caustic cleaners are used necessitate the use of a NEMA 4X enclosure. A few examples are NEMA 4X enclosure applications for food processing facilities (where total wash-down with disinfectants occur repeatedly), petro-chemical refineries and offshore drilling platforms for oil and natural gas. The NEMA 4X enclosure is used when protection from the worst environments is required. Many NEMA 4X industrial enclosures are available in sizes from small wall mounts to two-door floor mount models. The NEMA 4X enclosures are available in 304 & 316 stainless steel. Also, Nemaco offers the Tough Tigerbox™ Nema 4X enclosure with continuous hinges, mounting feet and sometimes padlock hasps. Tigerbox™ NEMA 4X enclosures are offered in sizes from small wall mounts to two-door floor mount enclosure models. Also, stainless steel passivation for additional corrosion protection is available on request for all the stainless steel products. 

NEMA 4 & 4X Cabinet Applications 

Due to the industrial demand of companies wanting to protect electrical equipment, companies commonly select environmental enclosures that maximize protection and minimize the risk of plant or manufacturing downtime.    Electronics packaged in water resistant stainless enclosures are an inexpensive solution compared to expensive manufacturing downtime in almost any process or manufacturing facility.  

Of all the different ranges of NEMA ratings, NEMA 4 has gained popularity and widely utilized for the protection it provides protection to the housed electrical equipment from foreign elements, extreme weather including ice formation on the exterior of an electrical enclosure. Aside from this, NEMA 4 also provides extra added protection feature – this is the lowest rated dust-proof NEMA electrical enclosure. Not only this enclosure provides the extra protection, it can also protect equipment from the splashing or hose-directed water. Even though NEMA 4 offers great protecting features, this enclosure is not to be used for any hazardous applications or use because it is not the explosion-proof enclosure. 

In addition to this, not only NEMA 4 has these features but also its subset rating the NEMA 4X. It also provides a wide array of protection like NEMA 4 but the later provides protection for electrical equipment from corrosion inducing foreign materials such as rainwater and hazardous liquids. NEMA 4X electrical enclosures are made from stainless steel and aluminium and these enclosures qualify for a corrosion-proof standard for the said electrical enclosure. To further explain the difference of NEMA4X to NEMA4, let us discuss the requirements for the former.  

Technical Requirements for NEMA 4 & 4X Cabinets 

1. Protection from moisture (water, rain, etc.) 

Type 4 enclosures are required to be watertight to prevent spraying water ingress. To measure the effectiveness of this feature, the enclosure must deflect hose directed water from a minimum of 65 GPM of water shot from a 1-inch nozzle coming from a distance of a minimum of 10 feet or above for at least 5 minutes of water exposure. At this rate of moisture protection, typically these types of enclosures can protect from any ingress of rainwater, ice formation caused by snows, water splashes, sleet and any other hose-directed water. Type 4 enclosures are designed not to be damaged because of any external ice formation on the enclosure – thus provides perfect protection from electrical equipment. 

2. Protection for Personnel using the enclosure 

Enclosures should provide protection for personnel using the equipment or enclosures from hazardous parts of the electrical equipment housed within the enclosure. 

3. Solid foreign objects 

Type 4 NEMA enclosures provide protection for the electrical equipment from foreign substances that may affect or damage the equipment. This includes but not limited to falling dirt, windblown dust, or lint. Even though all the electrical enclosures are designed to protect the equipment from foreign objects and substances, the type 4 NEMA enclosures are the lowest-rated standard for the dust-proof enclosure. 

4. Tight Gasket Sealing 

Typically, NEMA 4 enclosures have a gasket affixed to the cover (door) that is compressed between the cover (door) and the enclosure body.  The enclosure body might have a rain gutter design for some designs.  Commonly, small boxes use JIC clamps to close the cover.   Mid-size to large size enclosures might use 3 point door latching system. 

5. Suitable for any Indoor and Outdoor Applications  

These enclosures are typically used for indoor and outdoor applications because of the level of moisture protection they give for the equipment. These applications are usually employed with wet, moisture-inducing outdoor applications. To further explain the point, these enclosures are typically used on ship dock, food manufacturing plants like dairy, brewery, and water-treatment plants. 

Additional Information on NEMA 4X Enclosures 

Most of the time, NEMA 4X is regarded as a waterproof electrical enclosure but no one can deduce that it can be also submerged in water. There is a specific electrical enclosure for that. But this enclosure is resistant to any intense water that protects the electrical equipment from allowing any water ingress. 

NEMA 4X Quality Tests 

In line with this, NEMA 4X enclosures should also pass several and rigorous corrosion tests that measure its quality. These include exposing the enclosure to 1200 hours of exposure to corrosion-inducing environments such as moist air containing carbon dioxide and sulfur dioxide. Both compounds are proven to hasten the process of oxidation in metals thus resulting to corrosion. The enclosure should also withstand the 800 hours of salt spray tests, this mimics rainwater which also induces corrosion among metals.  

NEMA 4 and 4X Enclosure Summary 

Additionally, these enclosures should be dust-proof and damage resistant caused by ice formation. Majority of these electrical enclosures are manufactured from stainless steel though not a mandatory. Stainless steel provides great key features a NEMA 4 and 4X should have.