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Frank Whiteley

Aging Surge Protectors

Frank Whiteley, CUGG

Had no idea, but it turns out those surge protectors that are protecting your electronic appliances wear out over time. That's because they've been doing their job. The Metal Oxide Varistors (MOVs) are slowly used up by surges that hit your house. Some spikes originate within the house also, when large appliances start and stop. Whole house surge protectors can be installed at the panels, but this is a job for the professional. As they wear out, they may lose their ability to protect. Some are equipped with lights and alarms to indicate whether they are still offering protection. Others, when fully consumed, will fail to deliver current. Some may need to be unplugged in order to reset. Interestingly, a few still deliver a trickle current that will show on the indicator light on the strip or even on the LED on the front of the PC, but the PC will not power up. Unplugging the strip from the wall outlet, waiting a few seconds, then plugging it back in will enable a reset and the PC will then power back up. If the strip will not reset, assume its life-cycle is complete and buy a replacement. I've had a few clients experience the trickle voltage, unplug to reset cycle. Another's strip would not reset and required replacement. Unfortunately, some of the indicator lights, or symptoms can be misleading and not indicative of any protection, just that they are plugged in and that they are not offering any protection at all. Read your product specification carefully. There are two aspects to consider when buying a surge protector, the amount of protection (in joules) and the clamping voltages. I understand that 1900 joules and more is better and that a clamping voltage should be 330 volts or less. Surge protectors manufactured prior to 1998 may actually be fire hazards. You want to find one that says UL Listed and UL 1449 2nd edition, not simply UL Approved or UL Tested. See for both Belkin and Stanley surge protection equipment. For high end protection, see


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