Number 217 - June 2001

Power for Pennies - Surge Suppressors
from the Jacksonville PCUG www.pcug-jax.org/ - Jan 2001
Florida is the lightning capitol of the world. Unfortunately, lightning strikes can cause electrical surges on electrical, phone and television wires. In some circumstances a lightning strike can cause an electrical surge on your home's wiring, even if the lightning did not strike your home or the power lines! There are things you can do to help prevent damage to your electronics by electrical surges.     What can I do to protect my electronic devices from electrical surges? Be certain your house is properly wired and properly grounded. The National Electric Code requires that there be one and only one grounding point for your home: the electrical system ground. All telephone and cable television systems must be grounded to that same ground point.     Install point-of-use surge suppressors. Install a surge protector device for sensitive electronic device in your home that you feel is valuable enough to protect. It is crucial that all incoming lines to a device be protected with surge suppression devices. If your computer has an uninterruptible power supply, (UPS), it may have surge suppression built-in. However, it may not have telephone line protection for the modem. Check product literature.     Install a main service entrance lightning arrestor. Main service entrance lightning arrestors can divert strong electrical surges that come in on the electrical wires. However, these devices DO NOT replace point-of-use surge suppressors.     What features should I look for in a good point-of-use surge suppressor? - Be sure to purchase a device that has all the types of connections you need. For example, if you are purchasing one for your computer, be sure to get one with a telephone connection for the modem. For VCRs and televisions, get a surge suppressor with cable television connections (CATV jacks). Remember, ALL connections to the outside world MUST be protected against electrical surges or your equipment can be damaged or destroyed.	Look for a surge suppressor that meets UL 1449 standards. Underwriters Laboratories tests devices for their performance as a surge suppressor. Other UL standards may simply indicate a device is electrically safe to use and may have no bearing on its performance as a surge suppressor.     Look for models with three-way protection. This means that all three of the wires in a device will be protected. Often, this will be noted as Lines protected: L-N, L-G, N-G. This means Line to Neutral, Line to Ground, and Neutral to Ground. Choose a model that has a Clamping Voltage of 330V. The clamping voltage denotes when the device actually starts working. When a surge of electricity comes in that is 330 volts or higher, the device will clamp, (switch on) to divert the surge energy away from the protected device. Generally, the closer the clamping voltage is to 330 volts, the better.     Try to find a model with a Joule rating of 300 joules or higher. The joule rating is an indicator of how much energy the suppressor can handle before failing. Therefore, it is an indicator of how long a life expectancy the unit may have. Unfortunately, not all manufacturers calculate the joule rating the same way. Different calculations can result in widely different joule ratings.     It is probably best to get a suppressor with a Maximum Surge Current rating of 10,000A or higher. This is the amperage rating for the device. There is also a Maximum Surge Voltage rating which will almost always be 6,000V, but then even the regular outlets in your home wiring system will arc over at 6,000 volts. So, maximum surge voltage rating is not very important. Maximum Surge Current ratings are important and can vary greatly. Many models are rated at 4,000 to 6,000 amps. Even experts disagree, but it seems prudent to choose a model rated at 10,000 amps or higher.
Number 217 - June 2001