Protecting Smart Home Electronics

Flawless uninterrupted performance from smart home equipment—whether for security, entertainment, or energy management—relies on a constant flow of pure electrical power.  When this energy is degraded or interrupted, a smart home can instantly become very dumb!

The greatest threat to home electronic equipment is a high-voltage power spike—from lightning, damaged power lines, or a blown power transformer at the street—which is delivered to your gear through the AC wiring in your home. If such a spike occurs, your gear will likely be damaged or destroyed.

The solution is simple: a Surge Protector.  It’s a device that’s installed between the wall plug and the equipment; one type diverts the dangerous surge to ground; the other takes the power hit directly, sacrificing itself to save your gear.  Major voltage spikes are rare—unless you live in severe storm country, are connected to a poorly-maintained power grid, or have faulty equipment in your home.  Fortunately, the cost to protect your gear from them is quite low, relative to the cost of the equipment being protected.

Minor voltage fluctuations can also be a threat.  They can enter the home from the power lines, or be generated from some electrical equipment within the home.  Neither source typically damages analog gear, but can degrade performance when they occur.  A vacuum cleaner, for example—can temporarily make the picture on an old analog TV very fuzzy, or distort the sound of your music.  Line Conditioners were developed to filter out these distortions.  Many high-quality surge protectors today also include line conditioning circuitry.

With the proliferation of digital devices in the home, a third problem has arisen—loss of initial programming or configuration, resulting in major frustration.  While digital gear needs protection from both major power surges and local sources of distortion—like the old analog devices—it is also vulnerable to subtle power fluctuations that line conditioners generally can’t filter out.  These cause digital equipment to freeze up, act dumb, and stop working.  Why?  Because these small voltage anomalies cause digital gear to lose their set-up configurations and programming.

Enter Isolation Devices.   In the digital world, such minor events as operating the kitchen fan or turning off the air conditioner can take a device or a whole system down.   Although the digital component(s) are rarely damaged physically when this occurs, the system will remain out of action until someone identifies the affected component and re-enters the correct configuration code, or unplugs the device so the circuits can auto reconfigure—a so-called cold reboot.   Digital systems are vulnerable to repeated complications of this sort, unless they are isolated from minor power anomalies.

While surge protection protects digital devices from destructive voltage spikes, and line conditioners keep them from distorting the sound (and picture), they are usually unable to protect digital gear from these small-scale annoyances.  Instead, isolation devices are needed, typically a UPS or isolation transformer.

The Uninterruptable Power Supply (UPS) was originally created to allow a computer user to avoid losing their work when the power goes out, by 1) serving as an absolute line conditioning device to protect the computer from damage, and 2) providing enough battery reserve to allow the user to save or back up their work.  A UPS consists of a constantly-charging battery (like the one in your car) plus a dedicated charger plugged into the 120 v wall outlet (to constantly recharge the battery), plus an inverter that converts the 12 volt DC battery power back to 120 volts AC.  The home digital equipment plugs into the UPS, so it is never directly connected to the 120 v AC wall plug.  As a result, the UPS protects the digital gear from the voltage anomalies that can mis-configure them—or worse.

For smart home installations, the goal of the UPS is to buffer all the equipment from the surges, spikes, and brown-outs that otherwise can wipe out the set-up configurations and cause digital frustration.  A second goal is often to prevent or delay the interruption of that all-important program you are watching (or recording), like the Super Bowl, the Oscars… you get the point.

In order to allow you to continue watching the show when power is lost, the UPS system must have a large enough battery capacity to support a system of equipment that is much more power-hungry than a home computer—and preferably for much longer than a few minutes.   After all, the show must go on!  This brings us to the down side of using a large UPS to protect smart home gear: initial cost and maintenance batteries.  Currently, large-capacity UPS units cost about $1500. each, with a large installation requiring maybe 2 or more units; and the batteries inside must be replaced every few years.

As an alternative, Isolation Transformers are available to filter out the smaller anomalies that can shut down digital gear.  They are less expensive than UPS devices, but they don’t provide backup power during an outage.  On the plus side, they are maintenance-free.

A additional option for uninterrupted use during a power outage is a whole-house Emergency Generator.  Unfortunately, these devices can generate significant power anomalies during their initial start-up cycle, generating the kinds of power oddities that can dis-configure— and even damage—digital equipment.  So be careful if you go this route.

Deciding how far to go–and how much to spend–to protect your smart home electronics will depend on local conditions: the power grid that supplies your electricity and the other electrical equipment inside your home; the extent (and sensitivity) of the gear   you wish to protect; and your budget.  But doing nothing is a decision not worthy of a Smart Home.

Written by: George McKechnie, Axiom Home Technology