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Surge protection that works

The Lowcountry gets a lot of lightning and a fair amount of unstable power. Most businesses think they are protected because something is plugged into something with a switch on it. Usually they’re not.

5 minute read

The power strip is probably already used up

Surge protectors work by absorbing energy, and the components that do the absorbing are consumed a little at a time. A strip that has taken a few years of ordinary spikes may have almost nothing left, and there is no obvious sign. The light stays on, because the light only indicates that power is flowing.

This is the important part: a dead surge protector keeps working perfectly as a power strip. It will continue to power your equipment and protect nothing at all, indefinitely, and nothing about it will change.

What a UPS actually does

An uninterruptible power supply is often bought as a battery for power cuts, and that’s the least valuable thing it does for most businesses.

The real benefit is conditioning. Utility power sags, spikes, and browns out constantly, and it’s the steady drip of that, not the dramatic strike, that ages power supplies and causes the mysterious reboots and disk errors that get blamed on software. A decent UPS smooths it out.

The battery matters too, but usually for a different reason than people expect. A server that loses power mid-write can corrupt its filesystem or its database, and the two minutes a UPS provides is enough to shut down cleanly rather than crash. That’s worth more than the two minutes of uptime.

  • Line-interactive is the right choice for most offices

    It corrects moderate sags and surges without switching to battery, which means the battery lasts longer and is available when it is needed. It’s the sensible default for a server, a firewall, and network equipment.

  • Standby units are fine for a desk, not for a server

    The cheapest category. They switch to battery when power fails and do little else. Acceptable for a single workstation; not adequate for anything the business depends on.

  • The battery is a consumable

    Three to five years, and it fails quietly. A UPS with a dead battery gives you no warning and no protection. Test under load annually and replace on age, not on symptoms.

  • Size it for shutdown, not for working through

    Unless you’ve a generator, the goal is a clean shutdown, not carrying on. Sizing for ten minutes is usually plenty and much cheaper than sizing for an hour.

The surge path nobody protects

Power is the obvious route in and it’s the one everybody guards. The routes people forget are the network cables, and in the Lowcountry they matter more than usual because so much equipment lives outside.

A camera on a pole, an access point on an outbuilding, a network run to a shop or a yard: each of those is a long conductor, often outdoors, connected directly to a switch inside the building. A nearby strike doesn’t have to hit anything to induce a damaging voltage on that run, and the damage arrives at your switch, not at your power strip.

The same is true of the incoming internet line, and of coax to a camera system.

  • Fit surge protection on outdoor network runs

    Inline Ethernet surge protectors, at the building entry and properly grounded, on any run that leaves the building. They cost a fraction of the switch they protect.

  • Ground properly, or none of it works

    Surge protection works by diverting energy to ground. Without a good ground connection there’s nowhere for it to go and the device is decorative. This is the part most often done badly, and it’s worth having done correctly.

  • Consider fibre between buildings

    Where a run goes building to building, fibre carries no current and can’t conduct a surge at all. It costs more to install and it removes the problem permanently instead of mitigating it.

What we recommend, in order

For a typical small business: a line-interactive UPS for the server, firewall, switch, and network equipment; ordinary surge protection on workstations, replaced every few years; Ethernet surge protection on anything leaving the building; and a properly verified ground.

Then, because none of the above is a guarantee, a backup that’s off site and tested. Surge protection reduces the chance of losing equipment. Backup is what determines whether losing it costs you a purchase order or your business.

Common questions

On this subject specifically. The full FAQ covers everything else.

  • How often should surge protectors be replaced?

    Every three to four years, or immediately after a nearby lightning strike. They’re consumed gradually by the surges they absorb and give no indication when they are spent. The indicator light only shows that power is flowing, not that protection remains.

  • Do I need a UPS if I already have a surge protector?

    For anything the business depends on, yes. A surge protector handles spikes; a UPS also handles sags, brownouts, and outages, and gives a server enough time to shut down cleanly instead of crashing mid-write. The clean shutdown is usually worth more than the runtime.

  • Can lightning damage equipment through a network cable?

    Yes, and it is common with outdoor runs. A nearby strike can induce a damaging voltage on a long cable without hitting it, and that voltage arrives at whatever switch the cable is plugged into. Any run that leaves the building should have inline surge protection and a proper ground.