What Causes A Power Surge?

What Causes A Power Surge?

What Causes A Power Surge?

Whenever a power surge occurs, it damages electronic devices instantly or gradually. Such impairments cause unexpected losses and lots of inconveniences. Power surges may also occasionally cause fires, especially when caused by lightning strikes.

Some people assume external factors are the only causes of power surges. However, although both internal and external causes are responsible, internal causes are the main culprits.

This article will give you a detailed account of what a power surge is, the causes, and what you can do when they occur.

What is a Power Surge?

A power surge/transient voltage is a sudden and massive current spike in your electric system.

Risks of Power Surges

  • Impairment of electric devices
  • Fires 

Causes of Power Surges

There are reasons why power surges occur, including:

Internal causes

  • Electrical overload. When you draw too much power from a single circuit, the overwhelmed circuit may receive an intense rise in current, leading to a power surge. Overloads occur when you overuse extension plugs or plug in too many devices on one circuit.
  • High-powered appliances. High-powered devices such as refrigerators, washers, dryers, air conditioners, and space heaters can cause surges when switched on.
  • Faulty wiring. Power surges will likely occur with damaged wiring or exposed casing since it offers minimal electric resistance.
  • Tripped circuit breakers. If the circuit breakers in your home are damaged, they pose a risk of power surges instead of protecting your appliances. 
  • Poor quality devices. Substandard devices can trigger frequent power surges in your home since they have low current resistance posing a risk to your valuable appliances.

External causes

  • Power blackout. A power surge is sure to occur during power restoration after a blackout.
  • A malfunctioning transformer. A malfunctioning transformer or faulty transmission line can cause a power surge. A small animal may also creep into a transformer and electrocute itself, causing a power surge.
  • Lightning. Lightning strikes can cause extreme power surges, which are destructive to your appliances.
  • Power company malfunctions. A power surge may also occur when your power provider is experiencing technical issues with the supply.

Signs of Power Surges

Power surges bring visible damage when lightning strikes cause them. But the effects may not be noticeable if the surges are small and internally triggered. 

These signs will help you identify an impending or a freshly occurred power surge.

  • Burning smell
  • Non-functioning devices
  • Buzzing, flickering, or dimming lights
  • Flashing of a device’s lights
  • Tripping of circuit breakers
  • Sudden resetting of appliances

Protection and Prevention of Power Surges

How can you prevent power surges from happening? Surges caused by factors outside your home are beyond your control. As for internally induced power surges, you can observe some measures to reduce or prevent occurrence. 

Since you may never know when power surges will strike, always protect your devices. The following measures will help you prevent or protect your appliances against power surges.

  • Disconnect all idle devices
  • Use separate circuits for each high-powered appliance
  • Ensure proper wiring 
  • Install a lightning rod if your area is prone to lightning strikes
  • Use power surge protectors
  • Invest in high-quality appliances and avoid all substandard devices


Power surges occur due to external or internal causes. They could cause apparent or unnoticeable but gradual damage to your devices. Thus, it is essential to prevent their occurrence and always protect your devices against damage.

A professional electrician is your most reliable resource when facing a challenging electrical issue or needing power surge protection.