Residential Surge Protection Using TVSS’s SPD’s Part II

June 7, 2009

damaged modemAn  analysis commissioned by State Farm Insurance found of 5500 detailed claims, more than half of the loss was related to telephone and electronic appliances.

As we become more connected through smart technology, AC power and low voltage or non-voltage carrying conductors become intertwined through the technology. When you think about it, more and more devices have an AC power cord  and a communications port for the transmission/reception of an external signal (video, DSL, etc.). Known as  “multi-port” equipment (AV Receivers, TV’s Modems, Computers, etc.) these devices add complexity to the transient voltage issue by creating additional doorways into the equipment. As we saw  in the AC Ground and Bonding article, external surges can enter the house as easily through the Telephone line, CATV or Satellite Dish as the AC utility. Studies show, even with a TVSS in the AC circuit, micro-electronics embedded in the equipment have failed due to transient voltages passing through the communications link. According to the same insurance study mentioned above, equipment including micro-electronics such as computers, TV’s, VCR’s and Satellite receivers recorded more significant losses than single-port equipment. This is not news to most of us. However, the point to recognize here is that any incoming services that arrive inside the house on a current carrying conductor (copper wire) has the potential to allow a voltage surge into the house and into our electronic equipment.

To make matters worse, having proper surge protection on the AC service and not on non-power related services may actually enhance the opportunity for a fault to occur in the multi-port equipment through surge current.  This  surge current  can create a  voltage shift  at the secondary-port on the equipment producing damage in the equipment. This voltage shift condition can also be rooted to a difference in voltage potential or ground reference at (you guessed it) the service entrance ground. This is the reason why we have seen more emphasis from the standards bodies (National Electric Code and National Institute of Standards Institute)  on the common grounding and bonding of all the incoming services (Telephone, CATV and Satellite TV) found in a typical residence. For this reason, in 1992 the IEEE  recognized this potential fault condition and coined the term Surge Reference Equalizer. Even though the industry has not really picked up on the term nor have they created a specific standard, the  UL1449 listing for this Class B surge protectors is acceptable for the time being.

 Proper Bonding and Grounding  Remain the Key Contributor to Both the Problem and the Solution

If you have read the four articles up to this point, you may think I am beating this subject to death, but grounding/bonding  remains the key contributor to both the problem and the solution. Complete the 8 point check list found in the AC Service Bond and Ground Part II.  If your house is less than 10 years old, it would be a fair assumption that all the incoming services enter near or at the AC service meter. Assuming all the services are bonded correctly as mentioned, you should be in good shape with the Telephone and CATV. For the rest of us, these services could attach any where around the house this also includes Satellite TV Antennas.  If possible, bringing all of these services within 20 feet of the AC Service entrance and attaching them as mentioned will assist in improving the ground system. (TIP: Satellite installations are typically located where they provide the best signal, bringing the ground termination from AC service entrance is important here as well).

Surge Reference Equalizer

surge protector class b 2At this point, we will assume that you have a good common ground with an equal ground reference. With that said you have successfully reduced the risk to multi-port equipment, BUT, both the IEEE and the NIST support the use of the Surge Reference Equalizer. As pictured, it looks like a typical Class B surge protector, but also has ports for communications ( RJ45 terminal, and threaded CATV terminal. With this type of TVSS there will be a PORT-IN and PORT-OUT set of connections.  Consider a Class B surge protector that includes both communication ports and CATV connections collectively in the same product for home theater equipment, set top boxes, satellite equipment, computers and any other mutli-port electrical equipment.  

Additionally Square D has release a whole house model that includes a Class C surge protector and the connections for Telco and CATV services. Tiered protection is still recommended if you decide to follow the whole house approach. (Square D Model SDSB1175C). NOTE: This method of reference equalizer is fairly new as previous practices supported keeping the services segregated until the point of termination, (CATV, Phone) independently until they reach the point of  use or the device that is common (i.e. TV, PC). As you will note, that is how I built my system. This is still an acceptable solution. 

Additional Choices – Surge Protection for Communication, CATV and Satellite:

Telephone Service: Most wire-line telephone service companies provide surge protection. If your telephone service was installed less NIDthan 10 years ago or has been worked on in that time frame you will probably have a NID (Network Interface Device) at the telephone entrance.  Telephone companies typically use “Gas filled arrestors”. Even though you may not have a NID, you probably have gas arrestors  if your phone  has been serviced in the last 20 years. Gas arrestors replace Carbon arrestors as the gas style will defeat the surge without a long term loss in service as they will self restore automatically. Since I built my grounding system before the Surge Reference Equalizer was readily available,  I placed an additional surge suppresor on my telephone line (Channel Vision C-0410). Much like the Telco provided unit it will disconnect the line in the event of a surge then restore it momentarily. Based on the performance characteristics of a Surge Reference Equalizer (SRE), in theory, I may still have a fault occur if my ground reference is not equalized and my Category A, B and C surge protectors are unable to defeat the surge prior to entering any of the protected equipment.  Since the current UL1449 is the only published document and it seems to favor an AC type failure,  for now, I am staying with my current system architecture using the C-0410  surge protection. TIP: You may have communications and/or video services provided by fiber optics. They will not have surge protection as optical services are unable to carry voltage or surge current.  If you are unsure if you have fiber optic services, the NID will have a consumer replaceable battery pack that you were informed about during the installation of the services.

4EDHICCAOT4EQ5CAS0S8SJCAJTJ6C8CATZJ50ECAZ5INCICAHEAI1MCAUYSD7KCAH7U0MDCAW5L3WSCA19XS37CAG3S3RACAVHVBMWCAXWUAI6CAED0UDWCAI9J2UFCAR71UZ8CA65BE4DCAQB2POKCATV and Satillite Services:In practice, the gas style arrestor  is used in these services as well. Because they use coax as a cable medium the arrestor looks a little different but perform in a similar fashion as the communications arrestor.

Theory vs. Science

One of the difficulties with this subject is it is very difficult to test your solution. To replicate a surge equivalent to a lightning strike is not feasible nor recommended. For this reason, surge protection, TVSS’s, SPD’s and bonding and grounding is not as black and white as we would like it to be and neither are the solutions. As you have seen in this article , there may be multiple solutions to the methods I have described. But overall, the method should still retain the same theme.   I have engineered large systems in multi story buildings and spent hundreds of thousands of dollars (not mine) to create the right grounding network  and still had recordable faults, so don’t think you will ever be 100% protected.  

One of the best articles written to date for residential bonding/grounding and surge protection is “Surges Happen”   produced by the Institute of Standards and Technology. This article covers the topic in very simple language and easy to understand instructions.

If you haven’t already, you may also want to read my 4 previous articles; AC Ground and Bonding, Electrical Switches and Outlets, AC Service Bond and Ground Part II, Residential AC Surge Protectors,

Key Inspection Points and Action Items:

  1. Annually check all your TVSS devices to insure the they remain in the protected mode (LED indicator).
  2. Follow the inspection routines as defined in AC Service Ground and Bonding Network by inspecting the mechanical connections and terminations.

In writing this series, it became apparent that I could not cover the subject in 1 or 2 postings. I hope I kept your attention and it made sense. Feel free to comment or send specific questions to Homeownerbob@gmail.com

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AC Service Ground and Bonding Connections Part II

May 17, 2009

electricalLightning is responsible for more than $5 billion in total insurance industry losses annually, according to Hartford Insurance Company.

  Here in the Southwest the weather is struggling between winter and spring which brings heavy rains and torrential thunderstorms. These conditions increase the opportunity for electrical surges and spikes. The impact of these storms can cause both personal and property damage. Proper grounding and surge protection can  be your best defense.

Unplugging electronic devices was the old school method of protecting our electronics, however with more microprocessor based equipment that may be built-in or hardwired it becomes difficult to do that.  This can be good and bad. On the good side, this “smart” technology can allow our washing machines to weigh the clothes to determine how much water to use, to our sprinkler systems determining how moist the soil is before it waters our landscape. On the bad side, all of these electronic devices are highly susceptible to the negative effect of power surges and spikes. Any technology less than 10 years old can easily be a candidate for failure due to technological advances based on micro-processor based technology. With all that said, it becomes very important to protect all of these devices from electrical surges and spikes. Even if you live in an area with very little lightening, or thunderstorms, your equipment is still subject to utility and equipment based electrical surges. 

Even though most of us recognize electrical surges as they occur from outside sources, (severe storms, etc.) power fluctuations (or spikes)  from utility switching equipment and even equipment within our house have the ability to create power transients that can have an impact.  So, to properly protect you and your house, you may consider going beyond the typical power strip or point of use (POU) surge protector by having multiple layers of protection.  Obviously, equipment such as a Flat Panel TV, computer or audio equipment require point of use (POU) surge protectors but including  Surge Protection at the point of entry (electrical service panel) will also provide protection for items such as dishwashers, HVAC systems, microwave ovens, washers, dryers and so on.    

tt43kicamiqr72cajlxf3qcaqg2uy9cataa1tgcaozp5xycal1ce1jcanvsd5ycaf7gwszca1aq9vncaubtid9cayql0nrcav7a5t3ca26lasucaabxmn3ca179qr3cagr0p6uca5rqldfca8ochrrProper surge protection cannot be discussed without stressing the importance of  a grounding network for your house. My article on bonding & grounding covers how to identify and inspect your system, but the subject warrants a bit more discussion. The reality of the situation is that your household experiences electrical spikes and surges regularly even without a storm in sight and the source can be any incoming services (Commercial AC, CATV, Satellite TV and Telephone Service) as well as electrical appliances in your house. 

Both the National Electric Code (NEC) and National Institute of Standards recognize the importance of proper grounding  by providing recommendations and standards to increase this level of protection. Read the following articles before you go too much further. For your house to be properly protected, the integrity of the complete house is essential. Bonding and Grounding, Electrical Switches and Outlets (especially testing of the outlets). TIP:  Any outlet without proper grounding should not be used for any electrical equipment that requires protection even when you have a POU surge protector plugged in.

Ensure your grounding systems is up to par:

  1. Test all your outlets as mentioned above.
  2. If your house is over 30 years old and the electrical service has never been upgraded, the water pipe may be the only source of ground. Adding a ground rod would be a good idea at this point. Add the ground rod near the electrical service meter and a new wire between the rod and the ground termination bar in the service panel. It’s okay to leave the cold water pipe connection in tack. The grounding schematic  found below is considered a perfect world design. Creating this form of grounding arrangement will optimize your ground system.
  3. Grounding SchematicIf you have a ground rod and it is over 20 years old, it may be time add a new one. Underwriters Laboratory (UL) recognizes standard copper clad ground rod have a life expectancy of 20 years. If the electrical system has not been upgraded, replacing the ground rod will be cheap insurance.  Its perfectly okay to have multiple ground rods connected together in an array. 
  4. National Standards recognize ground systems with less than 5 ohms of resistance as being acceptable. Unless you live in a very dry climate or have known issues, testing an installed ground rod may not be necessary. If you are thinking you need to replace it,  it’s cheaper to just add it than have it tested.OYL94SCAGD0QOUCAYL04A3CAWYLBW6CAAH81G0CA0L2SH0CAHPGADSCAA7UEPWCAR3W6D8CAEFUGXNCAWGM712CAE6Z75SCAHKAUTPCAM64A17CAYGWHLQCAY41LE9CAXSYBESCAAW9HKRCASITYXC
  5. Ensure that all CATV, Telephone, Satellite services are collectively grounded at the same location as the AC service. TIP:  The closer these services are to each other and the shorter the ground wires used to connect them; the better.  Using the proper grounding hardware, the ground wires can be connected together at the ground rod, or you can use a collection device like the one pictured.    
  6. NEVER EVER connect a ground wire or ground rod to a natural gas pipe.
  7. As noted in the Grounding Bonding Post, having all the incoming services enter the building in the same general vicinity is most desirable.  TIP: With existing houses, these services may already be installed. If you are remodeling or building, keep this item in mind as you go through the process.   When the services all enter from different locations, surges may travel through the house to reach the intended ground source. Unfortunately in those type cases, this can increase the opportunity for the surge to follow an unintended path that may include passing through a television or computer.
  8. Following these items will reduce the risk and opportunity for surges and spikes, however damage from direct strikes are nearly unavoidable. 

 Odds Stacked Against You:  Having  a good ground system as mentioned above will protect you in most cases, however there are certain issues that will work against you. Some of the conditions you can change,  some not. Either way you need to be aware of them. 

  1. Tall structure; having the tallest structure in the general vicinity
  2. Having the largest or tallest trees in the area
  3. Large antennas, such as amateur radio
  4. Located near open water
  5. Older vintage building wiring systems that did not include proper or adequate grounding
  6. Living in an area served by aerial electrical, telephone or CATV lines
  7. Living in an older neighborhood with numerous tree’s in the utility easements
  8. A combination of any of the previously mentioned situations

I know this is a lot of information, but these grounding issues are regularly overlooked until a failure or problem has occurred. If you see the value of this, but its over your head, consult with an electrician about evaluating your system and performing the upgrades for you. My next article will cover the actual surge suppression devices (aka. TVSS). We will see the different classes of TVSS’s, where and how to apply them  and how to recognize a good one.  Look for my next post on Residential AC Surge Protection Using SPD’s and TVSS’s.