Breaking the Bad Structured Cabling Habit

I had a technical talk in Iligan Institute of Technology, Mindanao State University last September 22 2016. This was in a gymnasium, the organiser choose that place to accommodate both the professionals, visitors and the students on its 1st JIECEP-IBC Summit 2016.

The seminar, “Implementing a Structured Cabling System”, is based on ISO/IEC 11801. My plan was to discuss the important issues ignored during the implementation. I have intentionally selected few sections to fit the allotted time. 

A Structured Cabling System (SCS) is a method for creating an organized cabling system that can be easily understood by installers, network administrators, and any other technicians that deal with cables. This method works best when you follow the standards. Industralized nations have the standards. Specialist / Engineers who made these standards have extensive experience over this technology. Every 5 to 10 years these standards are reviewed and change when necessary to fit in the current technology.

These are just the few common standards:

• ISO/IEC 11801
• CENELEC as EN 50173 – Europe
• TIA/EIA 568B – U.S.A.
• CAN/CSA T529 – Canada
• AS/NZS 3080- Australia and New Zealand

When we are going to work with Structured Cabling System we need to pick a standard. Unfortunately in the Philippines we still have that “defiance to the law” that keeps us unproductive over our ASEAN neighbors.

These are the usual Menus to choose:

• None at all
• Famous Brand
• Pick and Mix from different standards
• Use Local and National Standards
• Use International Standards

If an electronic industry doesn’t have an adviser to his business he will let the installer (even pick contractor without experience or certification on electronics installation) to make the decision. Or that contractor might choose a famous brand and crosses his finger that everything will turn out fine, unknowing of the danger ahead.

The Philippine has the National Building Code of the Philippines (PD 1096) which supposedly “consistent with the principles of sound environmental management and control; to provide for all buildings and structures, a framework of minimum standards and requirements to regulate and control their location, site, design quality of materials, construction, use, occupancy, and maintenance.”

The National Telecommunication Commission (NTC) which lays down many rules regarding the use of telecommunications equipment within the Philippines. And the RA9292 (Electronics Engineering Law) is the legal base of the electronics practice for electronics engineers and technicians.

We have beautifully crafted laws but not all Local Government Units (LGU) knows how to implement them. Thereby we cannot guarantee the key points below:

1. SAFETY – Standards are made by experts, you cannot go wrong with the technology.
2. COST effective and simpler to deploy – You made the right choice, it is worth the money.
3. EASY to troubleshoot – If it is done right, you know the wires like the back of your hands.
4. LEGAL issues – Seriously you don’t hire lawyers to layout cables.

To share an interesting check and balance idea, in the U.S. they have this UL - the American Underwriters Laboratories Inc., an independent, not-for-profit product safety testing and certification organization. What they do is to make a series of test to check if the products specification is true if not, it is unsafe.

So why again do we need the standards?

Most of us have been in government agencies, you might notice the usual delay of any transaction and if you are keen to see the problem at the background you will see why. If we follow the standards strictly, LANs, telecommunications and data communications systems, etc. then performance will work predictably.

Standardized Structured Cabling

ISO 11801 structured cabling conforms to the three-layered hierarchical model. Composed of the horizontal cabling, the building backbone cabling and the campus backbone cabling. Figures below illustrates this:

Any wrong decision you’ll made will severely affect cost but we should never violate the standards.

There are ways to make the three layers in either copper or optical cables work for you. The COA, as fibre-to-the-desk (FTTD), optical home-run and collapsed back-bone. In using the optical fibre, we won’t be needing the other layers like the building or floor distributors. You may consider high speed LANs which are limited to 100-m transmission distance over copper cables, but they can go further over optical fibre.

Enough Bandwidth
Obviously the bigger the bandwidth the more information carrying potential that channel has. It doesn’t mean that we can go beyond the specs. The mHz.km is the representation of how much bandwidth is available per unit length.

Example:
If an optical fibre is rated at 500MHz.km, it means that in a 2-km link, 250MHz of bandwidth is available.

Points to remember: There must also be more signal than electrical noise or interference on the cable or the receiver will not be able to distinguish the desired signal from the background noise.

What Category of copper cable to pick?
• Multi-pair Category 3 cable is still the most cost effective for backbone telephone cabling.
• For the horizontal, that is the Fibre-to-the-Desk cabling, Class D/Category 5 is adequate. This will supply up to 1000Mb/s of data to the desk or up to 100MHz of analogue video signal.

Screened vs. Unscreened
Electromagnetic compatibility (EMC) is viewed as an electromagnetic emissions requirement
Electromagnetic immunity (EMI) is a measure of the device or system’s capability to reject outside electromagnetic interference.

A well-balanced and engineered cabling system must not degrade the EMC performance of any active equipment connected to it.

CISPR 24, EN 50082, NTC *

Fire performance of indoor cables
Some of you might remember the Asbestos, it was a material used in industries that are resistant to heat, and when asbestos fibers are breathed in, they may get trapped in the lungs and remain there for a long time. Over time, these fibers can accumulate and cause inflammation, which can affect breathing and lead to serious health problems.

We should seriously check the type of materials where using in Structured Cabling System to make sure it will not pose health hazards. As few example, below are what you will see on the brand catalogue:

• LSF (low smoke and fume)
• LSF0H (low smoke and fume, zero halogen)
• LS0H (low smoke, zero halogen)

Halogens are a class of elements consisting of:
• Chlorine • Iodine • Astatine
• Fluorine • Bromine

These are the things that when burned will affect electronics devices and us.

IEC standards relating to fire performance issues are: (Just the few)

IEC 60332-1: Flammability test on a single burning wire.
• IEC 60332-3-24-c:

Flammability test on a bunch of wires.
• IEC 60754: Halogen and acidic gas evolution from burning cables.
• IEC 61034: Smoke density of burning cables.

Halogens – points to remember.

• PTFE (polytetrafluoroethylene)
• FEP (fluoroethylene polymer)
• (Teflon ® ) types of materials.

* They contain halogen and fluorine.

Pathways and Spaces

Spaces are an essential and integral part of the structured cabling system, they are enclosed areas that house cables, equipment and terminating hardware. They include the telecommunications room, the equipment room and the building entrance facility. Well in some business they are actually using these space as guard room, business room, it defeat its real purpose.

ISO/IEC 15018 (one example)
Information technology – Integrated cabling for residential and SOHO (small office, home office) environments.

Pathways
The cable must have a defined route that will protect it according to the environment in which it exists.

No standard exists that details exactly what kind of cable pathway is required in different circumstances.

General rules concerning the installation of data cables

• Cable ties must not be too tight

• Cables must not be forced around bends tighter than that specified by the manufacturer

• Cable bundles must not be too big

• Cables must not be dragged around or across sharp edges

• Power cables must cross data cables at right angles and should be separated from each other by a ‘bridge’

• Cables clipped directly to wall surfaces must be supported at 300 mm in unsupported horizontal runs, at 1000mm for supported runs and 400mm for vertical runs (BS 6701 7.2.5)

• Never run cables parallel to your electrics (Many are still doing this – dangerous)

EN50174-2: (one reference)
Information technology
Cabling installation
Installation and planning practices inside buildings

Earthing Grounding & Bonding

Earthing, grounding and bonding essentially covers all aspects of ensuring that all exposed and other extraneous conductive surfaces are connected to earth and all cables screens are all effectively earthed.

In a structured cabling system the equipment racks, the active equipment, the metal patch panels and conduit, tray and trunking would all be considered as extraneous conductive parts and must be effectively earthed.

In a screened cabling system all of the screening elements of the cables, patch panels and connectors must also be earthed for the screening process to be effective.

Points in electrical bonding systems

• SAFETY from electrical hazards.

• RELIABILITY in signal reference within the entire information technology installation.

• SATISFACTION in electromagnetic performance of the entire information technology installation.

Equipotential bonding
The permanent joining of metallic parts to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct safely any current likely to be imposed.

TIA/EIA-607) or bonding *
ANSI/NECA/BICSI 568-2001 *

Earthing is connection of the exposed conductive parts of an installation to the main earthing terminal of that installation (BS 7671).

Equipotential bonding is electrical connection putting various exposed conductive parts and extraneous conductive parts at a substantially equal potential (EN 50174-2).

Grounding is a conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of earth (TIA/EIA-607).

Administrative Schemes

Maintain accurate records of what the cabling consists of, what kind of connections there are, what kind of numbering scheme is employed and to have an organized method of administering changes. Yeah, the installer will test them all but few will do the documentation, you will certainly regrets it later on.

Few of the standards of doing it:
ISO/IEC 14763-1: Information technology – Implementation and operation of customer premises cabling – Part 1: Administration.
EN 50174-1: Information technology – cabling installation – Part 1: Specification and quality assurance.
ANSI/TIA/EIA-606: Administration Standard for the Telecommunications Infrastructure of Commercial Buildings.

The Electronics Engineering Law of 2004 or most commonly known as RA9292 as legal bases for the practice of electronics engineering, we are continuing an advocacy that our local government will implement the law sincerely.