What's the Difference between 'Room,' 'Cabinet,' and 'Closet?'

Just a little over a year ago, TIA TR-42.1 and TR-42.3 officially decided to change the acronym for the telecommunications room from TC to TR to eliminate confusion and to ensure that the industry realized that a “room” instead of a “closet” was required on each floor of the building. Well, the latest proposal and work item before these committees may bring back the TC term, but this time it will refer to “cabinet” versus “closet.” Actually, the official name of this work item is Cabinet TR. Only in standards activity can a cabinet be considered a room.

In the spring of 2001, a study group was formed within TR-42.3, the committee responsible for pathways and spaces recommendations and the TIA-569A Commercial Building Standards for Telecommunications Pathways and Spaces. This study group was referred to as the “Tiny TR” study group. The effort was primarily being driven by the modular furniture industry, which wants to address the need to have active electronics out in the open office area. Actually, this discussion started outside the standard organization as soon as the TSB-75 Additional Horizontal Cabling Practices for Open Offices was published and officially recognized the consolidation point as an option for the open office. Since that time the industry has seen a limited number of manufacturers introduce products for and users implement active electronics in one form or another in the open office area.

It must be said that Cabinet TR Task Group has just started their efforts and is a long way from finalization. Any decisions made up to this point have an opportunity to be modified or changed. The task group in trying to establish a scope of their efforts developed three potential options for consideration. The options considered were:

• Mini-hub in the work area.

• Hub at the consolidation point or multi-user outlet.

•  Cabinet TR located in the open office.

In November 2001, it was decided that only one of the three options had enough support to be developed further.

• Option 1, with a mini-hub in the work area, was found to already be allowed by the standards as long as the minimum required horizontal cabling per user (one voice and one data) is maintained; therefore, no action was required.

• Option 2 was the most controversial option because it opened up major concerns relative to administration, suitability for electronics, and the displacement of some horizontal cabling drops by electronics channels.

• Option 3 received enough support for further study and development. It is similar to Option 2, except it differs in some very subtle ways, such as the following:

• Option 3 is viewed as extending the backbone cabling from the telecommunications room out to the Cabinet TR versus simply placing data hubs at the consolidation point in essence in the middle of the horizontal cabling system.

The consolidation point has a limited number of requirements as an enclosure and can be placed in a number of different environments in the open office area. These include ceilings, under the floor, and in furniture, given the consolidation point was initially defined as a passive device. With Option 3 defining a new device, the Cabinet TR, it is expected that the requirements on the Cabinet TR will be more extensive than those of the consolidation point.

The task group has to address a number of significant items in specifying the requirements of the Cabinet TR. These items include grounding and bonding, which is always a very difficult subject; adequate lighting; access to the cabinet; temperature (heat) dissipation; dedicated circuit(s) for power supply; manual emergency power disconnection; administration; and sizing relative to number of users, just to name a few. The question to ask after the standard is completed is: Will this be a cabinet out in the open office area or a metal room on feet? Of course, the economical feasibility of the distributed Cabinet TRs versus a centralized TR will be a major concern. This is not only as it relates to the provisioning and cost for the cabinet, but also as it relates to the cost of cable versus electronic ports and the installation and maintenance of both.

It is critical to understand that this effort in no way is planned to effect the present requirement to have a minimum of one TR per floor found in the TIA/EIA-569A. This will be a very interesting standard to watch develop. It is amazing how things evolve, because back in 1987 in the first discussions that evidently led to the first edition of TIA/EIA-568, the TIA committee rejected the Digital Equipment Corporations proposal for inclusion of their Cabinet TR. EC

BEAM is director of systems marketing at AMP NETCONNECT Systems. He can be reached at (336) 727-5784 or tebeam@tycoelectonics.com.

About the Author

Tony E. Beam

Freelance Writer
Tony Beam is director of systems marketing at AMP NETCONNECT Systems. He can be reached at tebeam@tycoelectronics.com or 336.727.5784.

Stay Informed Join our Newsletter

Having trouble finding time to sit down with the latest issue of
ELECTRICAL CONTRACTOR? Don't worry, we'll come to you.