Enclosures undergo rigorous testing to determine their compliance with NEMA 3 standards. These tests include:
- Penetration Test: A rod of specific size is used to attempt penetration of the enclosure’s interior.
- Water Spray Test: The tops and sides of the enclosure are sprayed with water at a pressure of approximately 5 psi, simulating sleet or rain under wind conditions of up to 5 mph. To pass this test, the interior must remain dry.
- Ice Test: This test verifies that the enclosure remains impenetrable and unaffected by ice formation, ensuring its continued effectiveness and usability.
- Dust and Dirt Tests: These tests ensure that fallen or windblown dust and dirt cannot enter the enclosure.
Furthermore, enclosures designed for outdoor use are subjected to additional testing to guarantee effective UV protection for the enclosed products.
What Does NEMA 3 Mean?
The designation “NEMA 3” refers to enclosures that are suitable for use in both indoor and outdoor settings. These enclosures have been specifically designed to be weather-resistant, providing protection for the components they house. This includes shielding against various environmental hazards such as dirt, dust, sleet, snow, rain, and even ice formation that could potentially cause damage. By meeting the NEMA 3 standard, these enclosures ensure the durability and reliability of the equipment they protect.
NEMA 3 enclosures offer an equivalent level of protection to NEMA 1 enclosures. They are designed to prevent any form of access from the exterior, ensuring that fingers or other objects cannot breach the interior. Various latching and locking mechanisms can be incorporated into NEMA 3 enclosures to further enhance their security.
Different Types of NEMA 3 Ratings
There are various types of NEMA 3 ratings, each with its own unique characteristics. These include:
NEMA 3R Enclosures:
A NEMA 3R enclosure does not undergo the dust test as it is not necessary to meet the dust standard. It may or may not have a dust gasket, depending on whether the application requires protection against rain.
Furthermore, a small drain hole is located at the bottom of a NEMA 3 enclosure to allow for ventilation and quick dispersal of any water that enters the enclosure.
Compared to lower-tier NEMA ratings, the NEMA 3R rating can stand up to additional weather conditions, providing comprehensive defense against the elements. This security is why the NEMA 3R electrical enclosure is common for junction and wiring boxes for utilities and communications and for housing other critical electrical components in outdoor environments.
NEMA 3S Enclosures:
Products housed in a NEMA 3S enclosure can still operate even when surrounded by ice. This test is typically conducted on both the NEMA 3S products and the enclosure itself.
NEMA 3X Enclosures:
Any NEMA rating that includes an ‘X’ guarantees corrosion protection for both the enclosure and its internal components. These enclosures are commonly used in environments close to salt water.
NEMA 3RX Enclosures:
A NEMA 3RX enclosure provides protection from corrosion but does not safeguard against dust ingress since only corrosion resistance is required for these specific products.
NEMA 3SX Enclosures:
A NEMA 3SX enclosure offers corrosion protection for products inside while allowing external mechanisms to operate seamlessly even under icy conditions.
At APX Enclosures, the NEMA type 3R electrical enclosure is one of our specialty protective cabinets. Each cabinet we manufacture is NEMA certified, UL Listed, weatherproof, non-corrosive and highly customizable to your specifications. Your product will be long-lasting and suitable for your application.