Selecting Equipment - How?
If you know what type of protection device you need and where to find it, you're half way home. But once you're at the store, how can you tell if one product is better than the other? Here are a few simple things to look for:
First, narrow your selection down to those products that are UL-listed as transient voltage surge suppressors. Only products that have the words "transient voltage surge suppressor," or the acronym TVSS, adjacent to the UL label are UL listed surge suppressors. Any number of products will have UL labels listing them as multiple outlet devices. This does not mean the product is a UL-listed surge suppressor.
"UL" or United Laboratories tests products for safety and performance. One of the most important performance characteristics of a surge protector is its clamping voltage. This is the voltage the surge suppressor will let through to your equipment before it diverts it to ground. The lowest clamping voltage recognized by UL is 330 volts or .33 kilovolts.
The product's clamping voltage will be listed on the product next to the UL label if it is UL-listed. Select only those plug in protection devices with a 330 volt clamping voltage. The label should also need UL 1449, the number of the UL test. Many manufacturers will list very low clamping voltages on their label or in their product literature. View this information for what it really is ... marketing hype. Use the UL number as your purchasing guide.
Over time, all surge suppressors will wear out. Most will provide years of service under normal conditions when used with a sound electrical system. However, it's important for you to be able to determine when the product fails. Look for products that use an indicator light, audible alarm or power disconnect as a failure warning. Without one of these, you could go unprotected without even knowing it.
Disregard any marketing information addressing the energy rating and response time of the product. Any UL-listed device meets these requirements. Once you've eliminated the products that aren't UL-listed and those without failure indicators, you can select a product that has the outlet configuration and protection modes you need.