Structured cabling systems have many elements that, due to their nature or installation conditions, must comply with the requirements established in electrical standards. Despite this, many people involved in the design and installation do not comply with these mandatory application requirements, either due to negligence or ignorance.
The purpose of this article is to list the main electrical standards, their references in wiring standards and their main requirements that affect the design and installation of structured cabling systems.
Each country, and even each locality, have their own electrical regulations, whose fundamental purpose is the safety of people; hence its mandatory nature.
The most relevant electrical regulations are the following:
- NFPA 70:2008 1 , National Electrical Code – Commonly known as NEC-2008, this standard is regulatory for the United States of America and other countries that have adopted or adapted it to their local needs.
- IEC 60364-1:2005 2 , Low-voltage electrical installations – Part 1: Fundamental principles, assessment of general characteristics, definitions. This standard, plus all others developed by IEC 3 standards committee 64 , focus on the
- protection against dangers caused by the use of electricity in building installations. .. NOM-001-SEDE-2005, Electrical Installations (use). Official Mexican standard that, although it is mainly based on NFPA-70 and IEC-60364-1, contains various requirements suitable for electrical installations in Mexico 4 .
Importance of the Application of Electrical Standards
Improper use and installation of electrical energy, even in limited power, can be a danger to living beings, the environment and material goods.
In electrical installations, there are two types of major risks: shock currents and excessive temperatures; capable of causing burns, fires, explosions or other dangerous effects. To prevent both types of risks, fundamental security protection principles state that appropriate protective measures must be taken against:
- electric shocks,
- thermal Effects,
- fault currents and
Protection Measures in Electrical Installations
- It should be avoided that:
- people and other living beings suffer injuries, burns or death;
- there is damage or loss of material goods; Y
- there is damage to the environment.
- To avoid the above, electrical installations must be planned and carried out to:
- prevent direct contact with energized (live) parts of the installation;
- prevent indirect contact with exposed conductors in the event of a fault;
- prevent direct or indirect contact with adequate barriers or separations;
- limit the current that can pass through the body to a value lower than the electric shock and overcurrent;
- activate the automatic disconnection of the power, in a period of time that allows limiting the current and not causing electric shock or overcurrent, in case of indirect contact;
- avoid the thermal effect, eliminating any risk of ignition of flammable materials due to high temperatures or electric arcs;
- use overcurrent protection to avoid excessive temperatures or electromechanical breakdowns;
- conduct a fault or leakage current safely, without reaching a temperature higher than the maximum permissible for the conductors;
- establish grounding and bonding methods for the safe conduction of fault currents; especially in case of indirect contact; eliminate excessive voltage caused by atmospheric phenomena, static electricity, faults in the operation of the interruption equipment or by faults between live parts of circuits fed at different voltages; Y
- Avoid overloading installed circuits due to poor planning or improper practices.