Unable to gFollowing is generalized information about design choices influencing SPD safety. As an overview, SPD failures are caused by system level sustained overvoltages. SPDs rarely fail from...

Surge Standards seem disjointed? Help is here! UL 1449 was revised into UL 1449 Second Edition Revision (Rev 2.5) to include Intermediate Fault Current Testing. This became effective Feb 2007. This...

Some caution should be used in evaluating the EMI/RFI filtering capabilities of a surge suppressor. MIL-STD-220B defines the basic testing procedures and test equipment to be used. However, there are...

The answer is subjective. Reasons for selecting larger kA ratings are one of the most misunderstood concepts in surge suppression. * I have a 100A panel - what size SPD do I need? * My customer has...

Lead lengths affect SPD performance. In simple terms, short and straight leads are better. Most electrical personnel have experienced a power line drop a few volts over several hundred feet. That...

Lightning has been the subject of research for decades. The data from this research is available for all to use. A number of institutions have spent many years trying to understand this phenomena....

APT SPD/TVSS are manufactured and tested in accordance with applicable industry standards. UL Marks are found on APT equipment. These are the most accepted and recognized safety certification marks in...

Multiple pulse or repetitive impulse testing is generally performed using IEEE C62.45-2002 recommendations using waveforms described in IEEE C62.41.2-2002. Often referred to as "pulse life",...

There are several IEEE surge standards in section C62. These address suppression components, outline surge environments, and offer guidance based on the collective input of hundreds of surge...

National Electrical Manufacturers Association (NEMA) may be best known for LS-1, but also serves as a collective mouthpiece for SPD manufacturers relating to other Standards such as UL 1449, IEEE C62...