Dear Mr. Electrician: What is the best surge protector that will protect my computer from lightning if it should hit my house?
Answer: In the case of surge protection, bigger is better but not always necessary. The ratings on various brands of surge protection device’s vary and can be confusing. I think that it is best to do some homework before making a surge protection purchase. Read reviews from other purchasers, compare the manufacturer ratings, check the price ranges for your budget.
Types of Surge Protectors
Some whole house surge protection devices connect to a circuit breaker while others are designed to connect directly onto the main terminals in your electrical panel without any circuit breaker protection or disconnect. There are also surge protectors that plug directly onto the bus bar inside of an electrical panel in the same location that a circuit breaker plugs onto. I prefer the type that can be disconnected if necessary for replacement or servicing.
There are also plug-in surge protection modules that are used to protect one electrical appliance or component. Surge protection power strips allow several electrical items to be plugged in and protected. It is important to read the labeling on these things. You should only buy something that has a UL label or other testing laboratory approval.
Grounding Your Surge Protector
Protecting your computer and other home electronics from lightning is not as simple as just installing a surge protector. When a surge protector limits the high voltage from a lightning strike, it will need a means to dissipate the excess current. In a well grounded home the surge protector’s lightning current would automatically be diverted to earth ground. The same is true for a plug-in surge protector power strip. The plug-in receptacle ground is connected to the grounding electrode system for the entire house and will only be as effective as the entire grounding system.
The home’s metal water service pipe, ground rods, well casing, and other metal pipes can be part of the grounding electrode system. In an older home a weak link in the system due to a loose or non-existent connection or corrosion of a component may cause the surge protector to be ineffective or in some cases hazardous.
Before purchasing a surge protector you should examine the main grounding electrode (Usually a water pipe or a ground rod or both) and the grounding electrode conductor connected to your electrical service. Lightning will usually follow the most direct path of least resistance to earth and you would prefer that it does not detour through any of your electronic equipment or appliances and cause damage.
Having an effective grounding system will not only enhance the electrical protection of your computer equipment, but all electronic devices such as TV’s, VCR’s, stereo amplifiers and receivers, microwave ovens, satellite dishes, and virtually anything else that is electronically or microprocessor controlled.
Some suggested reading in the “National Electrical Code”: Article 250 on Grounding, article 280 Surge Arrestors, article 285 Surge-Protective Devices. Other books to read are Soares Book on Grounding and Bonding and NFPA 780 Standard for the Installation of Lighting Protection Systems.
A good post for you to read is how I grounded and bonded an older home due to the homeowners concern about lightning damage.
If you need to update your grounding electrode system you should read my post.