Ask the Editors: Should I Get a Surge Protector, Power Conditioner, or UPS?

surge protector

Q: I’m upgrading my AV system for the first time in 10 years, and I want to do it right. I like the aesthetics of the power conditioners I’ve seen, but they all cost a good deal more than a quality surge protector. I understand (first-hand) the importance of surge protection, but I’m not so clear on the value of power conditioning or how to tell if it is needed.

When does a power conditioner add value over a good surge protector? Does a battery back-up UPS also function as a power conditioner? Does a good power conditioner need to be replaced any more (or less) frequently than a quality surge protector or UPS?

– Steve Delaney? (smdelaney)

A: Let’s start with a look at these three types of power-related products. A surge protector or surge suppressor is designed to prevent high-voltage spikes or transients from damaging electronic equipment. If the voltage increases beyond a certain threshold called the clamping voltage, the energy is diverted away from the main outlets to the ground.

Another important parameter is the response time, which is the time it takes for the surge protector to start operating after the clamping voltage is exceeded. Then there’s the maximum amount of energy the surge protector can handle without being destroyed. In many cases, some of the internal components can degrade after the surge protector has done its job, which means you might have to replace it after an adverse event. Even if you experience no such event, some components degrade over time, so you should replace surge protectors every few years.

A power conditioner “cleans up” the AC power signal by filtering out any noise that distorts the otherwise sinusoidal waveform. This isn’t much of a concern for modern electronic equipment, in which the power supply includes its own noise filter. Most power conditioners also include surge protection, and they attempt to maintain the output voltage in the event of a voltage sag or “brownout.” In other words, they try to keep the AC voltage constant no matter what, though they can only go so far in this regard. Still, they typically offer greater protection than a simple surge protector.

Finally, there’s the uninterruptible power supply (UPS). This device includes a rechargeable battery that supplies power to the connected devices in the event of a power outage or severe brownout. Normally, the backup power is intended to last only a short time so you can safely power down the connected equipment until the main power is restored. When the power comes back on, there could be a voltage spike, so it’s better to have the equipment off when that happens. Many UPS devices also incorporate surge protection and power conditioning.

Surge protectors are important if you live in an area prone to lightning, which can cause voltage spikes on the power line. However, nothing will protect your equipment from a direct lightning strike on your home’s electrical system. And remember that you’ll need to replace most surge protectors every few years or whenever they are called into protective service. Get one with the shortest response time and highest energy handling you can afford.

In my opinion, power conditioners are not necessary unless you live in an area with frequent brownouts and/or extremely noisy power—which does not apply to most first-world locations. Some people claim that a power conditioner can improve the video and/or audio quality of your AV system, but I have seen no evidence to support that. So, I do not recommend getting a power conditioner to improve the performance of your system.

One benefit of a power conditioner is centralizing and managing the power for several pieces of equipment. With many models, you can set them to power their outlets on and off in a programmable sequence, which is great when certain devices need to be powered on or off before or after other devices. However, don’t use this approach to power off a lamp-based projector, which needs to cool down carefully. Virtually all lamp-based projectors keep the internal fan blowing for a while after you turn them off. If you turn them off from a power conditioner or power strip, they can’t do that, which shortens the life of the lamp.

A UPS is very important if you live in an area with even occasional power outages. This is especially critical for projectors with lamps, as discussed in the previous paragraph. If there’s a power outage while a projector is operating, the fan can’t cool the lamp properly. The UPS battery keeps a projector powered on until you can shut it down safely. Also, the equipment won’t be bothered by any voltage spikes when the power is restored. However, the battery in a UPS won’t last forever; you’ll need to replace it every few years.

I’m sure there are some AVS Forum members with additional thoughts and opinions on all this, and I welcome their comments.

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