Some of you undoubtedly know this, but I feel that it needs to be said given some of the posts in this thread: A UPS will not offer significant protection against a lightning strike.
I understand the mistake since people understand that a UPS will switch over to batteries if the line voltage drops too low or in better units also if it rises too high. That switch action, however, takes milliseconds to trigger. Meanwhile, in the first few hundred microseconds, the voltage spike has already done its damage. UPS units themselves typically offer some, albeit extremely limited, surge suppression. A high end unit like a SmartUPS 2200 might offer 480 joules worth of absorption capability, and it's most likely just through a MOV. MOVs are not the fastest to react devices and they degrade over time as they absorb energy.
If someone cares about the equipment within their home, I would suggest the following:
- Spark gap arrestor before the main breaker, on your cable drop, and on your phone line if present. Phone lines should always have a spark gap at least within the US, but your cable line likely does not.
- Either whole-house surge suppression before the main breaker or quality suppression on each outlet where you care about what is connected
- Surge suppressor on both phone and cable, ideally before any distribution within your home
- Any suppressors used should ideally have multiple kinds of protection elements such as TVS diodes (never wear out, limited capacity, react in nanoseconds), MOVs (wear out over time, moderate capacity, react in microseconds), and gas tubes (never wear out, high capacity, react in milliseconds) and also offer protection between each conductor instead of just hot to ground. Your surge may not come in on the hot wire.
It's also important to make sure that if you're going to protect a device that it's fully protected. Many people make the mistake of putting their computer on a surge suppressor but then leaving the Ethernet connection unprotected. I can't tell you how many times I've seen charred Ethernet adapters with destroyed inductors, traces, and controller ICs that inadvertently saved the machine in question. Many others are not so lucky. This can happen quite easily in a common scenario like this: A user has a desktop and a cable Internet connection. They have their cable modem/router and desktop both plugged into surge suppressors but not the incoming cable feed itself. A surge can come in on the cable connection and fry not just the router but potentially the desktop as well since they're connected together, unprotected, over Ethernet.
Whole house surge protection is available from many power companies for a small monthly fee of like $5-10. If the device gets hit, most power companies will replace it for free. Additionally, it's worth noting that if you don't protect everything (and unfortunately, even if you do), you are susceptible to a nasty spike crossing from an unprotected line to a protected line if given an opportunity. You might find that your unprotected power drop in a wall allowed an avenue for your protected Ethernet setup to have a spike induced on it.
In the end, no device will ensure you don't lose equipment. All you can do is take reasonable precautions to protect yourself. For most people, unplugging everything in their home before every storm isn't a reasonable option. It also doesn't help much as a strategy if you're at work or traveling when the surge hits. Even actions as simple as the power company throwing a distribution switch can cause a voltage spike, and the weather forecast won't help you there.