Volume 14, Number1
February 2003 Copyright
2003 CRITERIUM ENGINEERS
The Engineering Advisor is intended to enhance your
knowledge of technical issues relating to buildings. For additional information on any subject, please feel free to
call us. Our commitment is to provide
you with timely, accurate information.
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CABLING CONSIDER- ATIONS FOR
NETWORKS AND TELE-COMMUNI-CATIONS |
The condition and appropriateness of the cabling within
a building is almost always an afterthought for owners and tenants alike,
according to Tom Wales, a Telcom consultant.
This is true despite the growing importance of telecommunications and
power systems in buildings. According
to Dennis St. Jean, of Graybar Electric, the telecommunications department of
this 100-year old electrical supply company has grown to equal the size of
the conventional power supply division just in the last ten years. Yet building owners pay relatively little attention to
these systems when purchasing a building, assuming it is the tenant who will
be responsible anyway. And most
tenants don’t yet have the sophistication to anticipate their cabling needs
before signing a lease. These systems
are analagous to the circulatory and nervous systems of the human body. Without them, the building dies. When connections fail, the building
deteriorates, a condition that might be compared to senility. |
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Types of cable |
Three types of cable predominate. Copper wire is the most common. The old CAT 1 cable that we are all
familiar with, used for phone lines, has been replaced with faster and faster
unshielded twisted pair (UTP) cable.
This cable also replaced coaxial cable in most workplaces. Today, however, fiber optic cable is the
preferred choice for speed, space, and security. Wireless connections are becoming more common between computers
and their hosts, but the communications backbone is still cable. Some of the old issues regarding safety and durability
remain concerns with fiber optic cables as well. Because they are glass, many assume that they are not
susceptible to lightning strikes. But
because they often have a metal central member, fiber optic cables may be as
susceptible as any other cable.
Surprisingly, fiber optic cable also deteriorates when wet. As a result, where the cable enters the
building and how it is protected is an important consideration. |
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What does a PCA
cover? |
Most companies, as part of their due diligence, will
order a Property Condition Assessment (PCA) before they purchase a
building. Cabling systems, however,
are not normally covered by engineering firms conducting such
assessments. These systems are also
excluded from ASTM Standard 2018-99 that covers most PCAs. It is not realistic to assess telecommunications
systems as part of a PCA, partly because technology changes so fast. New technologies like Power Line
Communication (PLC) may make old cabling systems obsolete. In a standard PCA, there are some covered areas,
however, that may be helpful in evaluating these systems. Most office buildings of any size will
have a room (or closet) dedicated to telecommunications equipment and
electrical switchgear. Some larger
buildings in fact may have one such room on each floor. The condition of those rooms is an
important indication of the condition of the systems. ¨ Is
the space conditioned? We have found
examples of such rooms that are not part of the conditioned space. Exposure to extremes of heat, cold, and
moisture take their toll on such systems. ¨ Is
the space clean and orderly? Very
often, this space is used as additional storage space. Boxes, spare furniture, even trash often
block access. That is a good sign
that the systems have not been maintained. ¨ Are
there service contracts? Buildings
large enough for a separate room for switchgear and telcom equipment should
also have contracts to maintain that equipment. Are contracts in place and what is the service history? |