If we look around our offices, homes, and neighborhoods, we would quickly see plenty of devices and systems that depend on low voltage wiring. It’s estimated that the number of active IoT devices will surpass 25.4 billion in 2030.
As a result, low voltage wiring will continue to play a critical role as we move into the digital age, making it vital for integrators, electricians, and DIY specialists to understand low voltage wiring code well.
This article will cover everything you need to know about low voltage wiring from cable to code and why it is crucial for security integrators and system owners.
What is a low voltage cable?
Essentially, low voltage cable (also called structured cabling or network wiring) is a wire designed to carry 50 volts or less. Important to note that most outlets run 120V or 240V of electricity but low voltage wiring doesn’t carry the same current as the power outlets, fixtures and switches typically installed in homes.
Low voltage wiring is often used for today’s modern appliances and IoT devices. Additionally, physical security systems, including alarm system sensors, intercom systems, and internet networks all depend on low voltage wiring.
The bottom line is that low voltage wiring is a wiring network that carries a low voltage current or low-pressure current compared to standard electrical wiring for medium- and high-voltage power transmission and distribution equipment.
Low voltage systems
Standard low voltages are 12V, 24V and 48V. Low voltage systems are comprised of electrical equipment that uses 50 volts (V) of electricity or less. Residential examples of low voltage systems include doorbells, garage door openers, home security sensors, thermostats, and landscape lighting.
When it comes to physical security systems, businesses can use wireless cameras or wired surveillance systems. Commercial low voltage systems cover various categories, from fire protection to security systems to sound and communication. Examples of low voltage systems include:
- Fire suppression systems: Low-voltage fire prevention systems like fire alarms and fire suppression systems are critical components of your total fire safety efforts.
- Access control systems: Low voltage access control system utilizes card readers, biometric scanners, and other means to restrict access to designated areas.
- Intrusion detection systems: Low voltage wiring enables intrusion detection systems to operate automatically and efficiently.
Regardless of the system, low voltage systems require an efficient network to function correctly. The National Electrical Code (NEC), or NFPA 70, is the widely accepted standard for the safe installation of electrical wiring and equipment in the United States.
What is code for low voltage wiring?
NFPA 70 is adopted in all 50 states as the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards. Moreover, organizations and municipalities frequently adopt it to harmonize how they manage and regulate safe electrical practices.
In addition, electrical wiring and low voltage power sources must comply with Class 2 of the National Electric Code (NEC). The code was developed to avoid electrical shock and fire. As a result, most licensed electricians and security integrators see the NEC as the industry standard for electrical standards.
National Electrical Code
The National Electrical Code (NEC), often known as NFPA 70, is a regionally adopted standard for the secure installation of electrical wiring and equipment in the United States. Government institutions and business and electrician communities have adopted it to ensure standardization and reduce civil liability for negligence.
The Committee on the National Electrical Code of the National Fire Protection Association, which consists of 19 code-making panels and a correlating technical committee, updates the NEC every three years. In addition, the code is revised to ensure it is current with safety and technological advancements.
NEC codifies requirements
The NEC codifies the requirements for safe electrical installations into a single, standardized source. While the NEC guidelines are not law, they are commonly mandated by state and local law, as well as many professional associations including the National Electrical Contractors Association as well as many jurisdictions outside of the United States.
The NEC covers the installation of electrical conductors, equipment, and optical fiber cables and raceways for the following:
- Buildings, structures, mobile houses, recreational vehicles, and floating buildings, both public and private
- Parking lots, fairgrounds, yards, lots, industrial substations
- Installations of electrical equipment and cables that are connected to the electricity supply
- Installations utilized by the electric utility that are not a part of a generating plant, substation, or control center, such as office buildings, warehouses, garages, machine shops, and recreational structures.
While it is not necessary to know all the entire low voltage wiring code, one should be aware of the risks and best practices in order to avoid the most common electrical code violations.
Is low voltage wiring required to be in conduit?
According to official guidelines, low voltage cables do not need to be in a conduit, but if it is part of an electrical installation, it needs to be in conduit. It’s also quite common to see low voltage wiring methods strapped to an existing conduit, especially above a suspended ceiling.
Regarding building structure, it must sustain cables and conductors installed exposed on the surface of sidewalls and ceilings to prevent damage from regular building use. In addition, NEC 300.11, which specifies when a cable can be fastened to the exterior of a raceway, must be followed while supporting cables.
Can you run low voltage wire through the wall?
Running low voltage cables through a wall is not problematic. Low-voltage wires can be run together in bundles. Running them through walls becomes much simpler as a result of this. As long as the wires are properly insulated, none of the signals should interfere with one another.
Depending on their location, low-voltage wires may be buried much closer to the surface than high-voltage equivalents and may even be left above ground, saving you the time and effort of digging.
How do you run a low voltage wire?
Low voltage wires should be installed a foot away, at a minimum, from the facility’s main electrical wires, running parallel with all the cabling. When working with low voltage wire, it is essential to read the manufacturer’s standards to determine the maximum radius of the loop. Cable fibers are prone to kinking or breaking, which can degrade the signal.
A point worth noting is that low voltage wires, such as fiber optic cables, can’t bend at a 90-degree angle. So you’ll have to form a loop if you need to turn it in a different direction.
Can you pull low voltage wire?
Low-voltage wires should not be pulled in the same manner as electrical lines. In addition, low voltage wires are incredibly delicate. As a result, they can be damaged by rough handling, which can reduce cable performance. The recommended draw strength is 25 pounds. However, every manufacturer has its instructions and guidance.
Do security cameras use low voltage wire?
Low voltage security cameras are used for a few different purposes and come in different types. In general, CCTV surveillance cameras supply power in one of three voltages. The three power supply options generally used in standard CCTV security cameras are:
- 12VDC-The Most Common CCTV Camera Power Supply Voltage. Most common security cameras function under 12 voltages.
- 120VAC- The household electricity of appliances used is delivered at 120VAC (volts alternating current) 60 Hz. (60 cycles/second) in North America.
- 24VAC- 24 VAC is commonly used as a control voltage not only because of safety but also AC is used over DC because it is easier for a relay or switch to “break” contact, and there is less arcing of the contacts.
Resources for low voltage wiring code
Low voltage wiring is a fixture in every modern-day household that powers crucial aspects of everyday life. From intercoms to speakers to thermostats, structured cabling helps residents automate their homes and use telecommunications and security technology.
Each state tends to have particular codes regarding allowance in renovations and at-home electrical wiring, so check with the local authorities to ensure you are following all guidelines and rules. Resources to learn more about low voltage wiring include:
- The National Electric Code (NEC)
- National Fire Protection Assoication (NFPA)
- Underwriters Laboratories
The Network Installers specializes in data cable installation, structured cabling installation, voice and data cabling, network installation, and fiber optic installation. When it comes to choosing the best structured cabling companies for your project, we’re your go-to low voltage contractor for the job.