While preparing for our much-anticipated summer storms, the we often overlook the digital backbone of our modern lives while focusing on our roofs, gutters and defensible space. Besides acting as an ignition source, monsoon lightning can wreak havoc on the contents of a building, even from miles away.
In the world of commercial communications, we often refer to a Motorola-published manual for site protection titled “Standards and Guidelines for Communications Sites” and known in the industry as “R56.” Together with the National Fire Protection Association’s National Electric Code, R56’s over 500 pages of detailed information has been keeping radio sites and dispatch centers safe and operational since 1987.
Although the methods of protection in R56 would be excessive for a residential structure, we can distill it down to some basic rules that can help keep our homes (and their occupants) safer during electrical storms.
First, we find all paths that lightning can follow into a cabin. The biggest connection to the outside is the power feed from Trico. You may have simple “surge suppressor” power strips protecting your computer, television, etc. from utility-line surges. These are limited in their capacity and only protect the device(s) directly connected to them. They can’t protect your major appliances (220v oven, electric dryer, etc.) that often have delicate silicon semiconductor chips buried inside. The best way to keep lightning-induced voltages spikes from riding the electrical lines into your cabin is a “whole house surge suppressor”. These are readily available from home improvement stores and must be professionally installed at the electrical panel where they can protect everything inside. (You can locate a licensed Electrical Contractor on the Arizona Registrar of Contractor’s website at http://azroc.gov/ .)
The next path to look for is a “backdoor” into the electrical system through outside electrical outlets. The extension cord that you may have run to your outdoor lighting, bug zapper or other outdoor appliance should be unplugged (at the outlet end) when not in use to cut off this path.
Finally, we have to examine our low-voltage communications paths. Century Link protects its lines where they enter your cabin, usually with a ground wire feeding into a gray plastic box near your electrical panel. If you use Century Link voice and/or Digital Subscriber Line (DSL) internet service, be sure this line is present and firmly connected to the ground wire below the electrical panel. If you don’t use land-line phone service, make sure all devices inside are disconnected from phone jacks – even an inactive line can provide a path for destructive voltages.
Your outdoor over-the-air television antenna and/or satellite television dish are connected to your electronics using coaxial cable, which should have been grounded when it was installed. Make sure that the green or bare copper wire is still connected to the coaxial “grounding block” which should be near where the coaxial cable enters the building. These grounding blocks, which are provided at no charge by satellite providers, are often insufficient for the extremes of mountain weather. Then can be easily replaced with coaxial surge protectors such as the TII Network Technologies Inc. modeI 212. Although they are not available for purchase locally, they are readily available online.
Simply Bits’ terrestrial wireless dishes are also grounded at the point where their Ethernet lines enter the cabin using a small gray plastic surge arrestor. If you have Simply Bits internet service, make sure the green wire from the surge arrestor is still connected firmly to the ground wire beneath the cabin’s electrical panel.
All of these methods of dissipating lightning energy before it enters a structure are dependent on a well-established electrical connection to the earth. Usually this is provided by an 8-foot long ground rod driven into the earth under your electrical panel. While it is impractical to properly inspect a ground rod once installed, it’s a good idea to make sure it is firmly anchored in the ground. If you can easily move it, it may have been cut short when it was installed or may have corroded significantly. A licensed electrician will be able to replace or supplement the ground rod if it isn’t providing an adequate connection.
The monsoon’s lightning and winds often cause power outages which can outlast backup batteries. If you have a medical condition that requires a powered medical device or refrigerated medication, now would be a good time to consider a generator with an automatic transfer switch. (If you already have one, make sure it has been serviced within the last year.) Since these are professionally installed and tied into your electrical panel and propane tank, they are far safer than portable generators. One prevented trip outside in your pajamas in the pouring rain to start up a portable generator is often well worth the expense.