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Choosing the Best Type 3 Surge Protection Device in 2018

The point-of-use protection is the third layer of surge protection. This device is the last line of defense against transient and over-voltage spikes that can fry any sensitive electronic components.

Once the massive overvoltages have been taken off the line at the service panel, the more sensitive components of point of use protection can come into play.

A good to excellent surge protectors should be able to sacrifice itself to block lower level surges that are damaging to electronics, including large LED TVs, refrigerators, washers, etc.

If you arrived on this page via a search engine, you may want also want to read Maintaining and Protecting Your Home Electrical Systems article

Unfortunately, the point-of-use surge protectors like “power strips” is one of those things that every needs but don’t give much thoughts until something happens due to a sheer amount of available products with wild performance claims.

The marketing folks from some of these companies want you to believe their products are so superior, they are willing to include a $250,000 warranty against damages to electronic devices cause by a surge.

A quick search on the internet and you will soon find out that with so many exclusion clauses in fine print, you will be lucky to get a replacement surge suppressor.

In my opinion, large assortment of surge protection devices on the market are simply junk and others a fire hazard so the moral of the story is take some to research and pay little more upfront and buy a good surge protection device.

Built in Features for a high Quality Surge Protection Device

Here are some characteristics that goes into making a quality SPD power strip:

  • Underwriters Laboratories (UL) approval;
  • Low resistance to grounding;
  • Automatic power disconnect if the unit fails;
  • Self-diagnostic feature (indicator lights and test buttons) to indicate whether the receptacle is properly grounded and the protection system is operating;
  • Contains high quality Metal-Oxide Varistors (MOVs);
  • Abundant receptacle slots;
  • Plenty of spacing between receptacles to accommodate bulky transformers;
  • Wall plug should rotate and have a flat profile;

Of course not every feature can be found in a particular device but more the merrier.

MAKE SURE YOU ARE NOT BUYING A SIMPLE POWER STRIP WITH A CIRCUIT BREAKER !! Many manufacturers carefully word-craft their descriptions to make it appear that you are getting surge protection. In fact, you are getting nothing more than a very expensive extension cord with a cheap circuit breaker that won’t protect anything other than starting a fire and that’s not guaranteed either.

Three Specifications of a Good SPD

Three technical specifications to watch when buying a surge suppressor: joules, response time and UL certification. Joules isn’t a rating on protection from a single surge, it is a rating on how many surges the suppressor can handle. It’s sort of a life expectancy rating. The experts recommend looking for at least 600 Joules. This APC suppressor gives you almost double that amount at 1,080 Joules.

Response time is also important. This determines how long your equipment will be exposed to the surge before the suppressor kicks in and clamps the voltage down. For this APC suppressor, the response time is a very respectable 1 nanosecond. That’s tech speak for 1 billionth of a second. Surges take a few thousands of a second to reach their peak, so this response time should be more than adequate.

The UL certification standard for surge suppressors is UL 1449. UL provides safety related certifications, not performance related certifications. A UL certification basically means that the surge suppressor itself and the equipment connected to it are extremely unlikely to blow up and start a fire when it’s hit with a surge.

Ignore “clamping voltage”. For technical reasons, you really want to watch the “Let-Through Voltage”. UL certification does include the specification for Let-Through Voltage with levels of 300, 400 and 500. This APC unit has a UL certification with a maximum Transient Voltage Surge Suppressor (TVSS) Let-Through Voltage of 300 volts, which is the best rating that UL provides for surge suppressors. Other manufacturers often make a big deal out of clamping voltage but avoid mentioning that their UL Let-Through Voltage is 400 or 500 volts.

Finally, a huge feature in a surge suppressor is a “Fail Safe” function. When a surge suppressor reaches it’s maximum Joules rating it quits providing surge suppression. The question is, how do you know that has happened? Most surge suppressors have an green idiot light (LED) that shows that the unit is still providing surge suppression. If you happen to notice that this LED has gone dark then you’re in luck. Most people don’t. A Fail Safe feature shuts the surge suppressor down so it no longer passes current through to your equipment. So, if your fail safe unit quits providing surge suppression, your equipment shuts down and you know the instant the surge suppressor has reached its life span. Very few manufacturers include a fail safe protection, so you continue merrily on your way until your $1,000 television or laptop suddenly melts down during a thunderstorm. APC provides fail safe protection on all of their surge suppressors including this unit.

Product Reviews

Product Name Rating
Best Type 3 Surge Suppressor Device (SPD)
WINNER – Tripp Lite Isobar HT10DBS allthumbsdiy-rating-stars-5-fl
RUNNER UP – APC SurgeArrest P11GTV allthumbsdiy-rating-stars-4-5-fl

Tripp-Lite Isobar HD10DBS


The Tripp Lite HD10DBS Home Theater Isobar is a heavy duty, all-metal surge protector that sports 10 outlets and is designed for demanding equipment like your home entertainment system or computer workstation. It features isolated filter banks to keep your electronics safe from line noise, and packs three coaxial inputs and outputs as well as one RJ-45 Ethernet inputs and outputs and one telephone input and output to keep devices along those cables safe from surges as well. The outlets on the top are well spaced, arranged so five are pointed in either direction on the top (so long power bricks can hang off of the sides), and two sets or two outlets spaced away from others to accommodate wide plugs and bricks as well. They’re even color-coded and labeled. Plus, the HD10DBZ packs an 8-foot cord, and comes with telephone, coax, and ethernet cables to help you get started connecting your gear to it.


which the majority of the surge protective devices on the market are not designed to protect against (this unit in question included) – for example, a temporary overvoltage (TOV) which can occur due to a tree falling on nearby power lines. Additionally, a surge protective device may successfully defend a residence from surge events over many years prior to ever experiencing an issue, with the owner unaware of these instances. A homeowner should regularly verify that their surge protection devices are operating as intended (usually by means of the visual indicator / LED’s).

Remember, these are surge suppressors NOT lighting arresting devices. A lightning strike on the power line feeding your home can literally blow wall sockets out of the wall. No surge suppressor is going protect you from all lightning strikes. For that kind of protection, you will need an electrician and some sophisticated protection installed at the point where your electric lines enter your home. That’s an entirely different level of protection and, as you can imagine, far more expensive than a surge suppressor.

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Tuesday 18th of May 2021

I am investigating a surge suppressor for a tankless water heater. I only require three outlets, the two listed above (outlet/coaxial wise) seem like over kill. Do you have a recommendation?

Thx, Guava