Electrician, Cook Electric
Written by Larry Cook

The Basics of Low and High Voltage for Homes

If you own a home, you’ve probably noticed the voltage warnings on wires, fixtures, and electrical panels. The following will cover the basics of low and high voltage for homes. Always work with a local licensed electrician for your family’s safety and the best results.


Voltage is one of several measurements for rating devices and power lines. High voltage is classified as having the potential to cause serious harm or injury. The International Electrotechnical Commission (IEC) considers high voltage to be more than 1,000 volts for AC (alternating current) circuits and 1,500 volts for DC (direct current) circuits. In comparison, the IEC rates circuits 120 to 1500 VDC (volts DC power) and 50 to 1,000 VAC (volts AC power) as low voltage.

Home Voltage

As rated by the IEC, home electrical wiring is low voltage. However, housing voltage, which ranges from 100 VAC to 250 VAC, is considered high voltage for home owners. Thus, 5 to 24 volt devices are considered low voltage in homes. Due to the rapidly growing number of USB-powered devices, the 5-volt USB outlet is now common.


Typically, a home has wiring in the 100 to 240 VAC standard. An electrical socket does not convert electricity, but supplies 120 volts to a 40 watt halogen bulb that uses only 12 volts.  A home’s electrical wiring will almost be totally line or high voltage because it is simpler for devices to transform the source voltage, rather than having each device conforming to a home’s electrical standard.

High-voltage circuits are standard, but there are instances when low-voltage circuits and devices are better. A home’s outdoor electrical fixtures are preferably low voltage because this will help ensure safety in wet weather. In contrast, a high voltage system may be required for large areas to supply adequate electricity.

Low voltage wiring is sufficient for energy-efficient lighting and smart systems. LED lights that are not made for standard sockets can instead be powered by low voltage DC lines. Similarly, smart home devices will require low voltage circuits for supplying their electrical needs.

Electrical Peace of Mind

Providing professional electricians since 1988 in Maryland, Cook Electric is the company you can rely on for all your electrical service needs. For knowledgeable, fair, honest, reliable, and conscientious service, call Cook Electric today at (410) 266-9040. We will be very glad to help you.