As a thunderstorm rolls in, you may be wondering if you should unplug your rooftop TV aerial to protect your TV or other electronics from a lightning strike. It’s a reasonable concern, but is disconnecting the aerial necessary or even helpful? Let’s take a closer look.
The Risks of Lightning Strikes
First, it’s important to understand the risks lightning poses. A direct strike can potentially send an electric surge through power lines and cables into your home. This can damage or destroy any connected devices.
An aerial acts as a conductive pathway since it’s made of metal. If lightning hits the aerial, the electric current could theoretically travel down the cable and into your TV. The same risk applies to cable TV connections and satellite dishes.
However, a direct lightning strike to an aerial is extremely rare. What’s more likely is a strike near your home sends current through the ground into the building. This can overload wires inside the walls. Considering most aerials are grounded to shunt surges, the cable itself isn’t the biggest concern.
Why Unplugging May Not Help
You might assume unplugging the aerial stops electricity flowing to your TV. But in reality, it makes little difference.
The main way surges enter your home is by travelling along AC power lines. Lightning can induce electric currents in any wires in and around your house. Disconnecting an aerial doesn’t prevent strikes from overloading other wires and cables.
Surges can even arc between disconnected wires that are close together. For example, if you unplugged an aerial cable from your TV but left it dangling nearby, electricity could still jump to the TV’s input port.
The multiple paths electricity can take into your home mean unplugging one cable probably won’t keep lightning out.
Use a Surge Protector Instead
Rather than relying on unplugging devices, the best protection is using a whole-house or multi-device surge protector. This specially designed equipment monitors incoming power and blocks excess electric current.
Installing a protector at your electrical service panel helps safeguard your entire electrical system. You can also use smaller surge protectors that plug into power outlets to defend individual devices.
Ensure any protectors you use are rated to guard against lightning by displaying a UL1449 certification. Other key ratings to look for include:
- Joule rating: 400V+ (higher is better)
- Clamping voltage: 500V – 700V
- Response time: <1 nanosecond
This level of protection blocks dangerous electric spikes more reliably than simply unplugging your TV or aerial ever could.
Other Useful Precautions
In addition to using surge protection, a few other precautions can help safeguard your home during storms:
- Unplug sensitive electronics like computers and game consoles when not in use. This eliminates dormant plug-in pathways for surges.
- Avoid using electric appliances that involve external connections, like corded phones or plumbing fixtures. Electricity can flow in through pipes and phone lines, too.
- Ensure your TV aerial, satellite dish cabling and other outdoor cables have properly grounded connections. This helps divert current from lightning safely into the earth.
- Turn off and unplug TVs, microwaves, routers and modems during storms. This reduces connected portals through which surges could enter.
Following these tips as part of a layered protection plan provides effective, affordable defence against storm damage.
The Bottom Line
While unplugging your TV aerial may seem prudent, it likely provides little protection. Electric current from lightning can still find other paths inside. Investing in professional whole-house and plug-in surge protectors offers a more reliable safeguard.
Prepare your home well and rest easier knowing your essential devices have proper defences against the tempestuous caprices of Mother Nature! Don’t stand too close to the windows to watch the dramatic lightning show.