standards and guidelines for communication sites - Radio And ...

WEATHERPROOFING/SEALING CHAPTER 3: COMMUNICATION SITE BUILDING DESIGN AND INSTALLATION
In general, observe the following considerations for sites utilizing transmission line connections from
an interior area to the exterior of a building or shelter:
• The entry of antenna transmission lines into a communications building or room requires a
weatherproof, commercially made port assembly specifically designed for this purpose. These
assemblies typically consist of a transmission line entry plate and boot assembly.
• A boot shall be used even if the cable is run through conduit. To avoid inconvenient rework in the
future, it is recommended to select a transmission line entry plate with enough ports to
accommodate the number of transmission lines at the site and allow for expansion.
• Entry plates should have 102 mm or 127 mm (4 or 5 in.) diameter openings. The plate is usually
made of painted aluminum, with from one to 12 ports per plate. A single entry plate mounted on the
outside wall or bulkhead is sufficient. See Figure 3-7.
FIGURE 3-7 TYPICAL ENTRY PLATE
• Cable boots corresponding to the cable diameter(s) shall be used. Cable boots are sized for the
transmission line they will carry and can be round, oval or rectangular. Some cable boots allow up
to three small (12.7 or 22.2 mm (0.5 or 0.875 in.)) transmission lines to enter through one boot. The
boot is usually made up of a two-piece cushion jacket, cushion (sized to cable diameter), and clamp
set.
• To reduce heat loss from the building, two entry plates should be installed inside and outside, with
rigid construction foam insulation between them. (Two sets of boots are then required.)
• The entry plate shall be installed per the manufacturer's instructions.
• The building/shelter and the port attachment to the building/shelter, shall be designed to prevent
animals or birds from nesting in and around the entry ports.
• Transmission line entry ports shall not be used to feed through tower light power, building ground,
or control cables.
• Boots shall be made of a material unaffected by ozone, sunlight, extreme heat, and cold.
3-12 68P81089E50-B 9/1/05