What a difference 20 Years Makes
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If
you first started buying surge protectors in the 20th century there are
two big things which are different today than then which you need to
know about. The differences is so large that I am replacing out several
of my old units. It may be time for you to do the same.
If you are an audio/videophile and are interested in understanding why power conditioning matters you may want to
start with an old post, but be aware that the recommendations have change a great deal.
Here they are in summary:
- Whole house units are required as of the National Electric Code (NEC) 2020 and they can save your life and home. Consider them even if your local ordinances have not yet adopted the latest version. Details below.
- Several
surge protection brands have come around to focusing on low let through
(or clamping) voltages instead of joules. This approach is something ZeroSurge and licensee SurgeX has been on the leading edge of for decades in the semi-pro/pro space, but it seems they've also been surpassed in performance and overall value. More on that below.
All
of the surge protectors I am recommending have let through voltages of
less than 200. Getting low let through voltages used to be something
only exotic brands like ZeroSurge had but now it's widely available in
more affordable units.
Note that while I use "let through voltage" and "clamping voltage" interchangeably the UL let through certifications only go down to 330 Volts. A manufacturer may therefore list the UL rated let through voltage and the actual clamping voltage separately.
The let through voltage of a surge
protector is how high a voltage would have to occur before the
protection circuits even notice it is happening. Circuits which limit
the let through voltages are key for several reasons:
- They work to slow down the surge, reducing the current that flows through your strip and therefore the home wiring.
- They
improves the reliability of the surge protector. The same surge won't
dissipate as many joules, so you can think of this as a joule magnifier.
- They start working at a much lower voltage protecting your equipment
- They add some noise filtering since they are essentially low pass filters.
Joules Don't Matter
Many
surge protectors are sold on the amount of joules they will "absorb."
This is actually kind of a misleading interpretation. Joules is the amount of energy the MOV's will take before is are destroyed and ineffective. It's better to think of joules as a bank account, and every strike takes money out before you are empty.
The clamping voltage is a better indicator of how carefully a strip will protect a given piece of gear. Cheap surge
protectors with high clamping voltages are still going to be slow to respond and may very high
voltages and current flow through your wall wiring.
Series
mode suppression really is the right approach at the outlets. You don't
want to cause a rush of current. You want to slow the current down and
put the voltage across devices meant to handle it. With Furman,
TrippLite and Panamax (same parent as Furman) now incorporating series
mode protection this is no longer the exclusive purview of Brickwall or
ZeroSurge, and that's a really good thing.
Cheap Strips Can Cause a Fire
Cheap strips without any filtering which use plastic housings can cause a fire through one of two ways:
- They will melt and cause a fire locally
- They
will cause so much current to flow through your home wiring that it can
melt the wiring in the wall and start a fire in there
So you want a strip that's low current solution and possibly has a metal housing which is much less likely to melt
Recommendations
For
the sake of your life and property I recommend that you use a
whole house surge suppressor IN ADDITION TO surge suppressors at the point of use with low let
through voltages. All of the outlet surge protectors I am recommending have clamping voltages below 200 and they are in the category of affordable and reasonable gear and all carry the appropriate UL or ETL testing certificates. They also use metal housings which makes them nearly fire proof compared to their plastic counter parts.
If you purchase a specialty audiophile "power conditioner" please check to make sure it is certified as a surge protector. Many of the uber-expensive units are certified only as a power extender or not certified at all or make vague claims about the surge protection included.
The recommendations that follow are a combination of my own personal experience and based on
actual testing from Wirecutter which is perhaps the only set of independent surge protection testing I've seen in the press. A lot of online sites review surge protection but only Wirecutter actually did surge testing for let-through voltages.
Best for General Use
This
is what I use everywhere except the audio/home theater or where I have a
UPS. At about $60 each they are a really good value for the protection
they offer.
Tripp Lite Isobar Ultra
Best for Audio and Home Theater
Furman
makes dozens of models of power strips and surge suppressors but the
feature mix that are must haves are LiFT and SMP and
these start around $130 for the PST-8. LiFT will reduce
noise (in the audible spectrum) on the line and SMP is a hybrid series mode surge suppression. These units will also turn off the power if the voltage is too high or too low for prolonged periods of time so even the most basic versions have advanced power safety monitoring and justify the additional cost.
The main reason buyers step up to Furman Elites are the premium home theater and audiophile features. These features vary greatly by model but after SMP and LiFT there are also units which include:
- Remote
triggers
- Voltage regulation
- Balanced outputs
- Coaxial protection
- Separate filter banks
- Power factor correction
The unit I use is the Furman 15i PFC pictured above. It is really pretty fully featured but it's around $1,000. If you want a Furman but don't care about isolated filter banks, coaxial surge protection, triggered outlets or power factor correction the Elite 15i is around $400.
If you don't need any of the
advanced features beyond surge and EMI/RFI noise suppression you should get a
Tripp Lite Isobar Ultra instead for the price. The low end ( < $150) Furman strips are just not as good as the units they are replacing. I still recommend Furman because at the higher end of the Furman product line the mix of features and reliability is absolutely excellent.
What about ZeroSurge?
ZeroSurge had been considered most reliable and
has significant noise filtering built in, and licensed by SurgeX. These serial mode protectors are among the most
expensive and they used to be among the best performing but this has changed over time. Now, based on
actual testing from Wirecutter we no longer recommend them as the best option. In particular it seems that the Furman have lower let through voltages, and have a number of features which make them more desirable and overall better values for the home user.
Based on discussions with experts off line, while the Furman does have an MOV after the series protection it almost never gets used. A good Furman should last you decades.
Networking
Besides
the power lines the other way in which a lightning surge can infiltrate
your home is via a cable modem. I use a gas discharge tube on the
outside at the grounding block and use an "air gap" kind of solution
inside. Compared to this, the risk of an induced lightning current in an Ethernet cable which damages equipment is actually quite small.
Between the cable provider's equipment and my own I use a 1m
fiber optic cable to prevent lightning from traveling through the
Ethernet cable to my PC's, TV's and audio streamers. Here's the list of
equipment I use:
There
are Ethernet surge protectors but after doing some reading and looking
at the reviews I decided to take it out. They aren't that reliable and
introducing a potential path to ground from the Ethernet cable can
actually cause a surge current to happen when otherwise there would not
have been one.
[Update December 2022] I have about a 50' run between my router and home theater setup.
I use a 4kV hospital grade Ethernet isolator at the end. It's much more convenient than the fiber conversion step and is in keeping with the idea of preventing current, rather than encouraging it.
Cable TV, Antennas, Etc.
I have kind of a lukewarm recommendation here. I say lukewarm because I had experience with it. This surge protector was in place when lighting took out several customer's and the provider's gear, but it did not ultimately protect the cable modem. Do I take it as a win because my router didn't fry? Maybe?
I do believe that this will prevent fire starting surges from making it into my home, but apparently it wasn't good enough to keep the receiver on the modem from being fried so this is not a strong buy recommendation.
Whole House
A
whole house surge suppressor can save your life and your home, especially home automation, fire alarms and large appliances. Get
an appropriate one for your panel. I prefer to use the kind that take
two breaker slots rather than the kind that are placed in a separate
enclosure. They are easier to install and are connect directly to the power plates. I
have used all but the Homeline here in the list below and while a
homeowner can usually install this themselves you should always learn and follow the laws which are appropriate for any home you work on or, better yet, hire a licensed professional:
As
a homeowner I would only live in a home with Siemens or SquareD
panels. If you have any other brand I suggest you check out this
website from an electrical engineer who
specializes in electrical fire forensics. Having said that the Leviton brand of whole house surge suppressors are not bad either. Another type of whole house surge suppression which meets the NEC 2020 guidance is installed at the meter itself. A non-electrician should never attempt to install these but being closer to the incoming wires they are a smidge better and safer in the case of a major high current fault.
Protip: Some utility companies will rent you a meter based surge suppressor for a reasonable fee. Worth considering if you don't want to pay an electrician.
Also, I know I said above that series mode protection is best, and at the point of use that's true, but a 200A series mode protector would be insanely large and expensive so these units DO rely on MOV's and shorting the surge voltage. Even so, their location right next to the huge incoming cables is the ideal place to shunt surge current.
Details
I
first installed a whole house suppressor near Boston in around 2000.
The goal was to protect the air conditioners and woodworking equipment I
had. At the time whole house protection was considered a fancy add-on but 20 years later
the National Electric Code has made these mandatory in new or upgraded
installations. Your local ordinances may be behind in their adoption of the 2020 NEC
but I hope that understanding the reasoning for this change will encourage
you to get one if you don't already.
The great
State of Minnesota posted an explainer: I quote them thus:
During the 2020 NEC code cycle it was substantiated that surge protective devices are necessary to protect against home fires
and personal injury. For the typical home, surge protective devices
also provide protection for all the sensitive electronic systems, a
variety of different equipment, appliances, lifesaving apparatus such as
smoke alarms and carbon-monoxide detectors, overcurrent devices such as
GFCIs, AFCIs, and much more.
The important most important
point here is is the fire protection. A big enough surge coming from
the power company can induce enough current in the wiring in the wall to
cause a fire which could possibly smoulder in the walls before
engulfing your home in the middle of the night. Also, being at the
meter or in the panel these surge protectors can channel a ton of
current to ground safely, much better this current happen here than at
your PC or TV. That surge current would have to travel through much thinner and
longer wires and this condition can be made worse by having a cheap surge strip.
The secondary considerations here are that we
have a number of important and delicate systems in our homes which are
now directly wired in, like fire alarms, smart thermostats, remote
lights, etc. in addition to major appliances. Major appliances can take
a hit here and there but will eventually wear down after repeated
smaller strikes.
Do not substitute a whole house protector for a surge strip. Use both. Here is why:
- The
best whole house surge protectors clamp around 500 to 600 volts. The
surge strips I am recommending clamp around 140 to 190 volts.
- While
the whole house protector wont' clamp until 500-600 volts it WILL take
on very high currents much more safely than the surge strips you plug in at the
wall.
Another way to think of this is that the whole house protector will protect your home from wire-melting current. The power strips will prevent you from equipment killing voltages.
