You may have heard electricians in Richmond, Virginia use terms like “low voltage” and “line voltage” when discussing electrical systems in homes or offices. In this post, we will focus on the difference between these two wiring systems, situations where electricians might use them, and the pros and cons of each.
The History of Line Voltage
Since George Westinghouse powered the 1893 Chicago World’s Fair using AC power, AC power has become the primary driver of electricity in residential and commercial buildings in the United States. Modern homes use electricity to power various devices, from refrigerators to televisions to gaming systems. However, at the end of the 19th century, households primarily used electricity to provide lighting.
The AC voltage standard became popular because it was cheap to distribute and could be used to power large areas. Most light bulbs function best if they are powered with a voltage between 100 and 110 V. This became the standard for electric power in the United States.
Line voltage describes how the electricity is delivered to a set destination, such as a business or home, through a power line that provides voltage. In the U.S., the voltage standard is between 110 and 120 V in residential settings. In other places, like Europe, the standard is 200 V plus.
How Are Low-Voltage Systems Used?
Low-voltage systems provide power to electrical equipment using 50 V of electricity or less. In most homes and businesses, low-voltage systems are 48, 24, or 12 V. You see low-voltage equipment in your home when you look at your doorbell, security systems, thermostats, garage door openings, and lighting used in landscapes. In a commercial setting, low-voltage systems are used for fire protection, communication, and sound systems.
Fire alarms, be them simple file alarms in an average residential building or complex fire alarm networks that link multiple facilities, use low voltage to ensure that everyone on the premises knows when there is an emergency and is alerted to evacuate during the crisis. Fire suppression systems utilize low-voltage power to detect the presence of a fire and trigger the release of dry, liquid, wet, or gas chemicals to extinguish the flames.
Building security is essential to prevent theft and keep building occupants safe. Low-voltage security systems include CCTV surveillance systems made up of cameras, digital recorders, and other devices that monitor what’s happening around the building, providing real-time footage that the owner can view remotely.
Access control systems are low-voltage systems that limit access to different parts of the building. These include biometric scanners and card readers.
Wiring Differences Between Low Voltage and Line Voltage
The NM cable is the most common type of home electrical wiring. It’s also called the Romex cable, named after a well-known wiring brand. NM cables have three or more conductors wrapped in a flexible plastic jacket or sheathing.
These high-voltage cables are used for interior home wiring for switches, outlets, fixtures, and hardwired appliances. The most common NM cables in modern homes are six, eight, 10, 12, and 14-gauge cables with an amperage ranging from 15 A to 55 A.
Low-voltage wiring is used with circuits less than 50 V. These are perfect for items that do not require much electricity, like your sprinkler system, a thermostat, a doorbell, or an alarm system. Low-voltage wiring varies from 12 to 22 gauge. It can be insulated or prepared in a cable sheath. Even though low-voltage wiring usually does not shock you, it is still a good idea to leave all low-voltage installation to professionals like those we have at Davis & Green.
Low-voltage wiring is also used for your internet and your phone system. The most common type of cable for networking is category five. However, modern phone and data cables can have between four and eight wires.
A category five cable has eight wires that are twisted together in pairs. This makes it highly efficient for data and phone transmission. Category five cable has a higher capacity and a higher quality than your typical low-voltage phone wiring.
Low-Voltage Versus Line Voltage Lighting
Low-voltage lighting has become extremely popular with energy-conscious customers. It is a system that uses transformers to take the standard line voltage of 120 V down to between 12 and 24 V. A typical application for low-voltage lighting is in recess, pendant, landscape, track, and display lighting. Low-voltage lighting does a great job of illuminating challenging-to-access areas.
Line voltage lighting is the typical system that uses 120 V to power lighting fixtures. With line voltage lighting, the system doesn’t use a transformer and can power fixtures in various applications.
Line voltage lighting is highly flexible. It can be used just about anywhere an electrician could install low-voltage lighting. However, the flip side is not true. Line voltage lighting can travel as far as you can run an electrical wire from its power source. It is typically integrated into the building’s architecture. Anything in most homes or commercial buildings that is not furniture or decorative runs on line voltage.
Low voltage is safe, offers more flexibility, and can potentially save you energy. However, a con of low-voltage lighting is the potential for voltage drops. If you connect several lighting fixtures, the resistance and kinks throughout the run can reduce the power that makes it to the final lighting fixture, impacting its performance. Additionally, since low-voltage systems are intricate, the potential for running into challenges during an inspection is increased.
Low-Voltage Versus High-Voltage: What Is Right for Your Home?
The electrical socket is not converting the energy in a typical home with 120 wirings. It supplies 120 V, even if your 40 W halogen light bulb only uses 12 V. In most homes, the line voltage is simpler to install. It’s easier to have the device use its transformers to transform the source voltage than attempting to get every device to conform to the electrical standard in the home.
Although the standard has been and continues to be high-voltage circuits, there are some circumstances where a homeowner could prefer a low-voltage circuit device. These are typically situations involving landscaping or the yard. Using low voltage in these circumstances helps ensure safety in wetter weather. However, if the outdoor area is more extensive than the line, line voltage may be needed to supply enough electricity to cover the area.
Low-voltage wiring is an excellent option for small smart systems. For example, LED lights that were not made for standard sockets can function on low-voltage DC lines. Additionally, if you have a smart home with multiple digital devices, you will need low-voltage circuits to keep these devices running correctly.
Providing Richmond, Virginia With Electrical Peace of Mind
At Davis & Green, we are proud to be a trusted name in the Richmond, Virginia area for HVAC, plumbing, electrical work, and general construction services. We are pleased to have a Better Business Bureau A+ accreditation and a staff of skilled professionals. We believe in honest, professional service and are committed to treating our customers how we want to be treated.
Our services include HVAC installation, repair, maintenance and water heater installation, repair, and replacement, including tankless water heaters. We install sump pumps, do leak detection and repair, and perform whole-home electrical wiring, inspections, and repair. Contact [company_name