Power Surge VS Brownouts: What Are They, and Top Devices for Protecting Your Homes

A blackout and power surge are things we have all experienced and fear–at least, it is very common in Nigeria. There is no power for an extended period or a higher voltage that blows up appliances. Almost everyone can see what is going on and should know what to do about it. What happens, however, if there is a brownout? Most people do not know what a brownout is, let alone what to do to protect themselves and their devices during one.

Brownouts infographic


A brownout is a voltage drop, or sag, in an electrical grid that is deliberate or unintentional. When demand for power exceeds supply, a short-term low-voltage deficiency occurs. Brownouts are most common during times of high demand, when too much electricity is required, or during severe weather. To avoid a total blackout, electrical suppliers may decrease the amount of power supplied to each home. As a result, homes would consume less energy than usual.

It describes a low-mains-supply situation in which incandescent lamps burn dimly or brownish rather than bright yellow or white. Brownout happens when the voltage drops to 150–180 volts on a 230V principal supply. Power sags, unlike temporary fluctuations like surges or spikes, can last up to a few hours.

What Causes a Brownout in the First Place?

Electrical grid failures usually cause brownouts, but utility companies can also impose them when demand for power is too high.

Electricity generation is a delicate balancing act. Electricity demand varies, and utilities use their network of generators, substations, and transformers to ensure that they are generating and distributing electricity appropriately.

When demand approaches or exceeds the utility’s maximum production capacity, the utility may throttle the flow of electricity in specific areas, resulting in a brownout. During a brownout, electricity continues to flow to your house, but at a lower voltage than normal. We name the event after the dimming of incandescent light bulbs that occur frequently during brownouts.

These planned brownouts could last anywhere from a few minutes to several hours, at which point electrical demand should drop and the utility should be able to restore full power. Brownouts may also occur spontaneously due to damage or malfunction within the grid or a nearby power plant, though this is much less common.

brownout is a voltage drop, or sag, in an electrical grid that is deliberate or unintentional. When demand for power exceeds supply, a short-term low-voltage deficiency occurs.

bright bulb

Power Surge:

A power surge is a sudden rise in voltage of over 110 percent over a short period. Outages, lightning strikes, and other power outages caused by utility companies are common causes. Surges in power can cause catastrophic damage to equipment, reducing its useful life and corrupting data.

When voltage fluctuations occur because of load fluctuations, power surges occur. When large loads are disconnected or tripped, the voltage increases to dangerously high levels (for equipment) and then drops in a matter of seconds. Surges only last a few seconds, but they are long enough to cause damage to electronic equipment such as televisions and computers. Some even cause refrigerators to break down.

The neutral wire in a three-phase load circuit may be disconnected in unusual circumstances. Under these conditions, it floats to a high voltage, and the phase to the neutral voltage at load will reach 400 V.

When the voltage on the power line rises, we know this as a power surge. One is when a motor, such as that found in an air conditioner compressor, generated a spike on the line. Surges usually last just a few minutes. You may encounter a situation where the voltage is increased from 110VAC to 130VAC due to low power demand. Because of the low demand, power grid losses may be low, resulting in higher-than-normal voltage.

Surges in internal power

Internal power surges account for more than half of all household power surges. These occur dozens of times throughout the day, usually when motorized devices start-up or shut down, causing electricity to be diverted to and from other appliances.

Refrigerators and air conditioners are the most common offenders, but hairdryers and power tools can also be problematic.

Surges in external power

A tree branch touching a power line, lightning striking utility equipment, or a small animal getting into a transformer are the most common causes of an external power surge.

Surges can also happen when the power is restored after an outage, and they can even enter your home via phone and cable TV lines.

Why Should You Be Concerned About Brownouts and Power Surges?

There are many items in your home that are vulnerable to power surges. Anything with a microprocessor is vulnerable; the tiny digital components are so fragile that even a 10-volt change can cause problems.

We can find microprocessors in a wide range of consumer products, including televisions, cordless phones, computers, microwaves, and even “low-tech” large appliances like dishwashers, laundry machines, and refrigerators.

Large power surges, such as those caused by lightning, can cause immediate damage, “frying” circuits and melting plastic and metal components. Fortunately, power surges are uncommon.

Low-level power surges will not melt components or blow fuses, but they can cause “electronic rust,” which causes internal circuitry to slowly deteriorate until it fails.

Small surges leave no visible signs, so you may not even realize they are happening – even though they happen dozens or even hundreds of times per day.

Brownouts: How to Prepare Your Home

Both power surges and brownouts can cause catastrophic damage to equipment, shortening its useful life and corrupting data, so these devices are essential for protecting your home.

Uninterruptible Power Supplies (UPS)

An uninterruptible power supply (UPS) is a device that allows a computer to keep running for at least a short time when the primary power source is lost. These devices can protect you from many power outages. These protect critical electronic devices from sudden shutoffs by providing battery backup.

Energy Storage

We used batteries in energy storage systems to provide backup during service interruptions. These can power your home’s most important systems. To become more energy independent, energy storage systems can be combined with home solar power. Energy storage systems may be eligible for incentives from utilities.

Smart Meters

Smart meters allow your energy provider and your home’s electrical needs to communicate more effectively. These will help you save money on energy while also giving utilities more data on how much electricity we used in the service areas.

Transfer Switches & Generators

During power outages, generators provide energy. Both portable and standby generators should be connected to a transfer switch to avoid unintended energization of nearby areas, which could endanger utility workers or neighbors. Install CO alarms and keep generators at least 20 feet away from windows and doors.

How to Get Back on Your Feet After a Brownout:

SPDs (Surge Protective Devices):

When full power is restored, Surge Protective Devices protect against voltage spikes that can damage your electronics.

You can purchase all these devices at Detopsy Electrical Shop, and enjoy discounts including FREE DELIVERY. Shop with us today!