When you house electrical components outdoors, durability and protection aren’t optional. They are critical to the safety and performance of your power distribution equipment.
EMI designs and fabricates NEMA 3R rated outdoor electrical enclosures for power distribution units (PDUs) and switchgear to protect your electrical equipment from rain, dust, wind, and temperature fluctuations. Let’s take a closer look at NEMA ratings and other weatherproofing considerations for outdoor electrical enclosures.
NEMA 3R Electrical Enclosures
NEMA 3R enclosures are designed to protect electrical equipment housed outdoors. This includes switchgear and power distribution units as well as meter enclosures, cable termination cabinets, and other equipment that requires basic weather resistance. NEMA 3R enclosures are ideal for most general utility and commercial outdoor applications as they provide broad protection against most weather while remaining cost effective.
Specifically, NEMA 3R enclosures are designed to protect against falling rain and sleet and resist external ice formation. They offer basic protection against dust and debris (NEMA 4 enclosures protect against windblown dust and hose-directed water) and allow for safe operation in non-corrosive outdoor environments (NEMA 4X enclosures protect against corrosion in addition to windblown dust and hose-directed water).
EMI builds and manufactures two different styles of NEMA 3R enclosures. Our non-walk-in enclosures are basic units with small footprints. They include a roof overhang and weatherproof door to protect switchboard components from the elements, falling debris, and tampering. We build these units for use on commercial buildings, such as strip malls or offices.
Our NEMA 3R walk-in enclosures offer protection to electrical equipment and workers. They are good options for larger facilities or industrial applications. In addition to weatherproofing, our walk-in units offer lighting, a 20-amp outlet, and forced-air ventilation.
Electrical Enclosure Materials
Choosing the right material for an outdoor electrical enclosure is vital to ensuring its long-term durability against the elements. Enclosures may be made of stainless steel, powder-coated steel, aluminum, or fiberglass.
At EMI, we use aluminum and steel in the construction of our outdoor electrical enclosures. Aluminum is lightweight and naturally corrosion-resistant and is ideal for utilities and telecom applications. Stainless steel and powder-coated steel are ideal for harsh environments, providing durability for general outdoor use while remaining an economical choice.
Electrical Enclosure Sealing Technologies
The sealing material used on electrical enclosures contributes to its weather resistance and durability. Modern sealing technologies keep out moisture, dust, and debris, even during severe weather or rapid temperature changes. Closed-cell foam gaskets, silicone or rubber gaskets, and multi-lip seal designs can all protect electrical equipment from dust and water while withstanding extreme heat or cold.
Electrical Enclosure Ventilation
Ventilation within your electrical enclosure minimizes moisture and condensation within the unit. Equipment such as breather vents, heaters or thermal pads, and desiccants can control condensation and prevent damage to wiring, relays, and other components over time.
EMI enclosures can include HVAC systems with heating, cooling, and ventilation options to keep your equipment working optimally and workers safe and comfortable.
Electrical Enclosure Mounting and Drainage
Even the best-designed enclosures can fail if they are improperly mounted and installed. Outdoor electrical enclosures should be installed above ground level to avoid water accumulation, and pads should be sloped to promote property run-off. Drip edges and rain shields can deflect precipitation away from equipment, as can drain holes or weep paths.
EMI enclosures are designed to drop over a concrete pad or be installed on a structural skid. They feature roof overhangs and other features to prevent water from entering the enclosure. Our walk-in enclosures also incorporate a weatherproof four-foot-long aisleway to ensure rain and snow do not enter the enclosure when workers do.
An enclosure is the first line of defense between electrical equipment and the elements. Investing in a properly weatherproofed enclosure means fewer service calls, less downtime, and greater peace of mind. For more information on our NEMA 3R enclosures, contact the expert EMI team today.