In-Building RF Plenum Cable Installations

for Wireless Systems

Times Microwave Systems

Times Microwave Systems

RF Cable Classifications & Requirements

Site Considerations

Cable and Connector Considerations

Installation

Testing

Site Maintenance

Overview

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RF Cable Classifications

Standard Duty Outdoor Cable (LMR®)

general purpose - can also be installed in conduit

Weatherproof Outdoor Cable LMR® DB)

more severe outdoor conditions – e.g. rooftops

Riser Rated UL listed (LMR® FR)

vertical riser/access shafts - unoccupied building spaces

Plenum Rated UL listed (LMR® LLPL)

can be installed anywhere in buildings

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Plenum Cable (LMR-LLPL®) Requirements

May be installed anywhere in a building without the protection of metal conduit

air-handling spaces & air plenums

Classified by NFPA and NEC/CEC (UL/CSA)

Fire-resistant, low smoke cables

LMR LLPL are rated CMP/MPP (UL) and PCC-FT6 (CSA)

Meet the UL910 ‘Steiner Tunnel Test’

burn length and smoke density are critical

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UL910 ‘Steiner Tunnel Test’

cables are arranged horizontally in the test chamber

suspended over flame source

smoke density & flame travel are measured

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Site Considerations Buildings are not cellular towers; In-building cables

must be especially flexible and rugged to withstand installation and maintain their physical & electrical integrity

New buildings

either cable-in-conduit or plenum cable may be viable options

Existing/legacy buildings

plenum cable is likely the only viable option

Building owner may dictate requirements including:

location of equipment

type of cable – owner may arbitrarily require plenum cable to be used for “perceived” safety reasons

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Important Cable Selection Criteria Loss

cable size: larger cables have lower loss, but are more expensive

construction (dielectric, shielding)

Cable Construction is Critical

electrical stability & long term reliability are directly related to cable construction and materials

cable must be sufficiently rugged to ‘survive’ initial installation

Compatible accessories

weatherproofing kits for outdoor/roof installs

ground kits – custom fitting

Low maintenance

cannot afford to have downtime

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LMR-LLPL® Corrugated Air Dielectric

Loss Very Good Good

Rugged Very Good Fair

Installable (no damage) Very Good Poor

Long Term Very Good Good Electrical Stability

Resistance to Possibility Very Good Poor of Water in Cable?

Maintenance Very Good Fair

Cable Comparison Guide

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Connector Selection Loss

should be less than 0.1 dB up to 1 GHz

High quality & reliable

machined, plated brass, captivated center pins

shouldn’t be the place to try to save money!

Ease of installation in difficult field conditions is critical to long-term reliability

non-solder (EZ) connectors

simple installation tools & accessories

Good selection of connectors

straight, right angle, different interfaces

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Cable

stay within mechanical parameters of the cable during installation

bend radius - avoid sharp bends

do not exceed tensile strength when pulling cable

do not exceed crush strength

protect exposed cable ends prior to connector installation (water/moisture/dirt)

Connectors

follow manufacturer’s recommendations & use manufacturer’s installation tools

use non-solder (EZ) connectors wherever possible

Installation

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Testing Dual purpose - initial site approval

& establish ‘benchmark’

Portable RF Test Set

e.g. H-P, Anritsu, Bird

program unit with the correct cable parameters (velocity, loss, etc.)

Insertion loss

verify against requirements & the manufacturer’s values

VSWR (voltage standing wave ratio)

Measure of the quality of the installation and connector attachment

Visual Inspection

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Site Maintenance(periodic preventative

maintenance) Recheck cable runs against ‘benchmark’ values:

insertion loss

VSWR

Visual Inspection

connections, bends

Outdoor runs

cable jackets

weatherproofing - connections, ground straps

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LMR LLPL® coaxial plenum cable, connectors, tools and accessories are specified in

Available from our network of distributors

Contact Times at 1-800-TMS-COAX