NEMA enclosures

Sometimes APs are located in areas where they are subject to extreme moisture, temperatures, dust, and particles. These APs may need to be mounted inside a sealed enclosure. The National Electronics Manufacturers Association (NEMA) has a rating system for these enclosures, which are generally referred to as NEMA enclosures . The ratings are shown in Figure .

The NEMA enclosures most often used for wireless networking products are Type 2, Type 4, and Type 4X. Some situations might require Type 12 or 13. These types of enclosures can be purchased through local hardware and electrical supply stores. Unfortunately, when purchased through these types of supply stores, the NEMA enclosure is not much more than a sealed box. There are no external antenna connectors, no external network connectors, no internal mounting standoffs, and no internal power supply.

Very few NEMA enclosures are available from supply stores with an internal power supply. Mounting an AP inside the enclosure can be accomplished the same way as when mounting an AP without an enclosure. Power will have to run to the enclosure and an electrical workbox installed inside the enclosure. An antenna mounted inside the box is not very effective, so an external antenna should be used. In order to attach an external antenna, a bulkhead extender will need to be installed. This is a simple connector that connects to the AP inside the enclosure and provides an antenna connector on the outside of the enclosure. Make sure that any holes drilled into the box are sealed. If even one hole is left unsealed, then the integrity of the enclosure will be compromised. Antenna connectors should be mounted to the bottom of the enclosure to provide as much protection from dripping condensation as possible. It is also a good idea to seal the antenna connection with a product such as Coax Seal.

Prefabricated NEMA enclosures with antenna connectors, standoff brackets, and surge protectors are available from third parties. They are more expensive than a standard NEMA enclosure, but provide better protection for the AP and can save the SE, the customer, and the installer a great deal of time and trouble. Special NEMA enclosures are also available that are temperature controlled and use solar panels to power the equipment. Make sure that the NEMA enclosure is securely mounted. A NEMA enclosure that measures 0.2 cubic meters (2 cubic feet) can weigh as much as 13.6 kg (30 lbs). If the enclosure is not properly secured it could fall, injuring someone, damaging equipment, or destroying the connected conduit for the power. Exposed wiring creates a potential fire hazard.

Lab Activity

Lab Exercise: Mounting and Installation

In this lab, the student will learn about wireless installation options and methods for the BR350 Bridge and the AP1200 AP.