What causes most power surges at home?
Most surges at home come from inside the house, not from lightning. Large motors and compressors, including your AC, create small voltage spikes every time they start and stop. Outside sources include utility grid switching, storm damage, downed lines, and power returning after an outage.
Because the spikes inside are small, they rarely cause a visible failure. They add up as wear on electronics, which can shorten the life of a television, a router or the circuit board in a modern AC system.
Larger events are less frequent but more dramatic. A nearby lightning strike or a utility fault can send enough energy through the wiring to damage equipment all at once.
How do Arizona monsoons connect to power surges?
Monsoon storms from mid June through September bring lightning, high winds and dust storms that can knock out power, and the moment electricity returns can send a surge through the house. Repeated outages and restores during storm season put extra stress on sensitive equipment.
Many homeowners notice a dead router, microwave board or garage door opener right after a storm. Sometimes the damage is not a single event but the last in a series of smaller hits.
A common habit that helps is turning off or unplugging sensitive items during a big storm. It is not a full solution, but it reduces exposure when you are home and can act.
What does a surge do to an air conditioner?
A surge can damage the control board, capacitors, contactor or compressor windings in an air conditioner, sometimes killing the unit on the spot and sometimes weakening parts that fail weeks later. Modern systems rely on electronic boards that are particularly sensitive to voltage spikes.
In a West Valley summer, an AC failure after a storm is more than an inconvenience. If your system stops right after an outage, switch it off at the thermostat and check the breaker before repeated restarts make things worse.
If the breaker keeps tripping or you notice a burning smell, sparking or a hot panel, stop and call a licensed professional right away. Do not keep resetting it.
How does surge protection help?
Surge protection diverts excess voltage away from your wiring and devices, limiting how much reaches sensitive equipment. A whole house protector installed at the electrical panel covers the entire home, while plug-in strips protect individual electronics and work best as a second layer.
Whole house protection is installed by a licensed electrician at the panel, and it should never be a do-it-yourself project. Work inside a panel carries serious shock risk.
Protectors wear out as they absorb events, so they are not permanent. Many include an indicator light showing whether protection is still active, and an electrician can check that during other work.
Which devices in my house are most at risk?
The devices most at risk are those with electronic circuit boards, including air conditioners, refrigerators, televisions, computers, routers, garage door openers and smart appliances. Simple resistive items such as basic lamps and toasters tolerate surges better than modern electronics do.
Anything that stays plugged in around the clock gets the most exposure, which is why routers and set top boxes tend to fail first. Replacing them over and over is often the first hint that surges are a real issue at the house.
Big ticket items deserve the most attention. An AC control board or a refrigerator board is far more costly to repair than the protection that would have helped prevent the damage, so think about the whole house, not just the cheap gear.
More questions: Surge Protection: 12 Most Asked Questions Answered