1. There is no such thing as a whole home Surge Protective Device (SPD).
2. The value of surge protection.
3. What is a power surge?
4. What is not a surge?
5. What is a surge protector?
6. What to look for in a surge protector.

1. There is no such thing as a whole home Surge Protective Device (SPD).

Targeting appropriate surge protection is as easy as doing a quick home walk through to consider entry points for transient voltages. The main entry point for surges outside the home is the service entrance panel to protect against indirect lighting strike and transient events caused by normal utility operating activity. The main panel SPD regularly gets the misnomer “whole home surge protector.” While a main panel SPD provides a level of protection for the whole home because the neutral electrical connection does eventually run back to the service entrance surge protector, it does not protect communication lines or any outside loads with a separate disconnect. Outside loads such as air conditioners, pool pumps and gate control panels are susceptible to surge damage due to increased exposure and can even become a pathway if the transient back-feeds through their circuitry and into the home’s electrical system. Our analysis divides a home into three zones of protection. Each zone works with the other to create whole home surge protection. Talk with your electrician to determine the most affordable solution that eliminates the greatest risk of damage to your sensitive electronic equipment. Always select devices that are UL listed to the most recent edition of UL 1449 and be sure they are applied according to their UL file listing.

2. The value of surge protection.

Transient voltages (commonly called “surges”) are a specific event. SPDs react when they sense a rise in voltage that triggers the device to “turn on.” Industry standards measure surges in thousands of amps, thousands of volts and millionths of seconds. These daily disturbances cause a form of electronic rust which over time can compromise electrical components. As the technology we have supporting our daily lifestyles becomes more sophisticated and microprocessor based, the greater the need to secure clean power.

Part of securing clean power can be accomplished by applying surge protection because AC circuit breakers don’t react quickly enough and GFI’s (Ground Fault Circuit Interrupters) are designed only to protect against shock hazards, and not as surge protection. Surge protectors are designed to reduce and divert potentially damaging short-duration voltage spikes safely out of the system to ground, similar in concept to how a pressure relief value that protects water heaters from overpressure. Next time that washer doesn’t cycle through completely or the home office computer suddenly develops a mysterious problem, consider that the “normal” wear and tear may actually be due to internally or externally caused surges.

3. What is a power surge?

A power surge (sometimes called a voltage surge) is a temporary surge of voltage within an electrical circuit. These power surges can harm or destroy sensitive electronics like computers and televisions. However, there are many more sensitive electronics in your home than you may consider at first glance. These include Washers/Dryers, cell phones, microwave ovens, LED lighting, or pretty much anything that may be plugged into a power source.

One obvious source for power surges is through lightening. But surges can be caused by other factors, including damaged wiring or components in your electrical circuits or by large motors (HVAC, pool pump, etc.) starting or stopping abruptly.

Even repeated minor surges can do irreparable damage to electronics over time. This can reduce the expected life of you equipment.

4. What is not a surge?

Many people may think there is a power surge when the lights flicker in their homes. This is not necessarily the case. There are instances where a utility power line may see an issue (like a short to ground). This short may cause utility fuses to blow or may have a recloser or other utility equipment to attempt to reconnect or reroute power. There are many things that may cause short blinks of power, but these don’t necessarily cause an excessive spike in power (voltage).

Additionally, if an electrical breaker in your home panel trips, it is not necessarily caused by a surge. Breaker tripping is usually caused by overvoltage, which means the circuit is using more current than it is designed for.

5. What is a surge protector?

Many people think that a surge protector is synonymous with a power strip. This is not the case. A power strip extends the amount of items you can plug into receptacle and they do offer over current protection (usually up to 15 amps), but they do not offer adequate protection for power surges.

Surge protectors (sometimes called surge suppressors) come in many styles and designs. Retail surge protectors usually come in power strip design, but offer the additional surge protection. A main home surge protector is usually housed in a small box and is connected to the load side of your main service panel.

Surge protectors monitor the system voltage and when a surge comes through that is above a clamping range, it reroutes much of the additional power to ground.

6. What to look for in a surge protector?

Surge Protection Devices (SPDs) are not created equally, so it is important to understand a few things to look for when determining they type of surge protector to get.

Know the difference between a surge protector and a power strip. It is a common mistake for people to believe that a regular power strip has surge protection. While they do come with over current protection, they generally do not come with surge protection.


Or This.

Surge Current Rating. The surge current rating is the amount of energy the unit will take before it fails. A higher number is better. For example, the ASCO Model 245 has a capacity of 39,000 amps before it fails. This rating shows the overall robustness of the unit.

MCOV. MCOV stands for Maximum Continuous Operating Voltage. This is the amount of voltage that the manufacturer guarantees the SPD can work with before turning on. When a voltage surge comes in at a higher point than the MCOV, the unit will activate and attempt to reduce the voltage at the set clamping voltage. For example, a surge protector that has an MCOV of 130V will start to work when voltage gets to some point above 130V. If the clamping voltage is 150V, it will attempt to cut off any voltage above 150V. It is important to have an MCOV rating and clamping voltage rating that are not too high, or too low.

Response time. Consider that you want an SPD that will react quickly to a surge. Know that the speed of electricity is very fast and if your device waits too long before it starts to direct excess current to ground, it may let enough surge through to still harm your sensitive equipment.

Make sure the product is UL listed and meets UL 1449 Standards. UL is a U.S. standard that assures the product has been tested and approved to be safe in your home. The UL standard 1449 specifically addresses protection from transient voltage. Make sure you are purchasing SPDs designed for transient voltage surges.

Consider your needs. Some local device SPDs only have receptacle plugs while others also have cable, LAN or phone connections that will protect surges from other than general electrical power circuits. Consider your needs for local devices prior to purchase.

Work with a company who has subject experts to work with you. There are many surge protective devices marketed on the internet. With all these choices, things can get confusing. Generally, you get what you pay for. Work with a company who has dedicated people to answer your questions and determine the best surge scheme for you needs. You may pay slightly more for the products, but you will have the personal interaction needed to make the best decision for your needs.