What’s the most dangerous appliance in your home? Chances are the devices that came to mind were not the ones that can fit in your hand. But it’s true that one of the biggest risks to your home is something we rarely even think about.
Take a moment to consider the humble surge protector. How many do you have in your home? A dozen? Maybe more? How long have you had them? They sit behind desks, couches and entertainment centers for years, sometimes decades, quietly protecting our electronics from sudden spikes in voltage.
But what many homeowners never realize is that surge protectors and power bars have a limited lifespan. Old units, especially the cheaper ones (and honestly, who prefers to buy the most expensive?) can actually become a fire hazard rather than a safety device.
Why Surge Protectors Wear Out
Most surge protectors (this includes power bars allowing you to plug many devices into one box) depend on a component called a Metal Oxide Varistor (MOV) to do what they are designed for. The MOV acts like a pressure relief valve for electricity. When the electrical voltage rises above a safe level, such as during a lightning strike or utility surge, the MOV absorbs the excess energy and diverts it away from your electronics.
We get a lot of surges, because we have a lot of power outages here in Windsor Garden. Every time the power comes back on, there can be a surge of voltage.
However, every time an MOV absorbs a surge, it degrades slightly. Over time, repeated surges slowly damage the material structure of that component. Eventually, the MOV can fail entirely. In many older surge protectors, there is no effective way for you to know when this failure happens. There’s no alarm, no flashing lights. So you never know.
Once the MOV is degraded, two things can happen: the device may simply stop providing surge protection, or worse, the internal components can become unstable. This can lead to something called arcing.
What is Arcing?
Electrical arcing happens when electricity jumps across a gap between two conductive materials. In a healthy electrical connection, current flows smoothly through metal conductors. But in aging surge protectors and power bars, several issues begin to happen, and you have no way of knowing they are taking place inside the device.
- Internal components can crack or degrade from repeated heat exposure.
- Dust and oxidation can build up on contacts.
- Plastic insulation inside the unit can become brittle over time.
These issues eventually create tiny gaps known as “high-resistance points” in the electrical path. When current tries to pass through these imperfect connections, it builds heat. If the voltage becomes high enough, electricity can jump across the gap rather than flowing through the conductor.
That jump is the arc.
Arcing generates extreme temperatures, often thousands of degrees Celsius in a tiny area. This heat melts plastic housings, ignites accumulated dust, and can ignite nearby materials such as carpet, furniture backing, or wall coverings.
Why Older Units Are More Dangerous
Older devices, especially those manufactured 15–20 years ago, and of course the bargain models, often lack modern safety features such as thermal fuses that disconnect the power in the case of overheating, or indicator lights, or even fire-resistant housings.
Without these safeguards, a failing MOV or damaged internal connection may continue conducting electricity even while overheating. This can then lead to a house fire.
A Simple Preventive Step
From a home maintenance perspective, surge protectors should be viewed as consumable safety devices, not permanent fixtures. Many electricians recommend replacing them every 5–7 years, or sooner in the case of a neighborhood like Hamilton that experiences many power outages.
If a surge protector feels warm, smells of burnt plastic, or shows discoloration, it should be unplugged and replaced immediately.
Replacing your aging surge protectors is a small investment, but one that can greatly reduce the risk of electrical fires.
Arc Sensor Option
Because I have quite a few surge protectors in my home, including a number of power adapters for electronic devices, appliances, and lights, I was concerned about the risk. I looked into it and found an arc sensor made by Ting Fire Safety. It’s a small device about the size of a night light that plugs into the wall. It takes about seven days to scan your electrical patterns, and then starts to work. The sensor continuously scans your voltage and electrical fidelity in real time. Sophisticated software analyzes the signal and instantly detects arcing anywhere in your wiring.
It’s pretty cool, showing me a graph of minute-by-minute voltage fluctuations for each day and sending me a weekly email report. When there have been power outages, I get an alert and the system records the exact time of the outage and the time power returned. We’ve had a number of cases where voltage drops below the 110 volt level, considered a “brownout,” so that I can also monitor how often this happens. These are a big risk for electronic devices, and each time there’s a brownout it creates a surge after voltage returns.
While it doesn’t eliminate the risk entirely, the Ting sensor lets me know if any of my devices have reached the point where they are dangerous. The unit is reasonably affordable at USD$99 and a USD$49 annual fee.
This post is also available in:
