Standards and Compliance

Perhaps the most recognized industry standard in North America for surge protectors may be UL 1449, the Standard for Safety for Surge Protective Devices ranging in applications from surge arresters (1000v ac max) to service entrance and distribution panels to plug-in surge strips. The standard was officially adopted as an ANSI standard in May 2010 and a supplement specific to the evaluation of Photovoltaic applications is expected in 2011. However, it is important to keep in mind that UL 1449 is first and foremost a safety standard. For more in-depth information regarding characterization of the surge environment, test methods and the application of these devices, the IEEE C62 standards are the definitive source in North America.

October 2010 saw the 74^th IEC General meeting in Seattle, Washington, USA. Within the IEC, its special committee CISPR (Comite International Special des Perturbations Radioelectriques –International Special Committee on Radio Interference) came together and this article reviews some of the key projects discussed at that meeting. The activities of IEC TC 77, a parallel committee to CISPR developing the IEC 61000 series and of equal importance, did not meet in Seattle and hence will not be discussed here except for the JTFs (Joint Task Forces) that exist in common with CISPR Subcommittee A, responsible for the basic standard CISPR 16, which will be the main focus of this first part of a two part article. In the second part of the article (to be published in a subsequent edition of this magazine), we will continue with the CISPR product standards and the Joint Task Forces (JTFs) existing between the different subcommittees as well as between CISPR subcommittees and IEC SC 77 B.

The electronics industry is continually shifting. Device density and technology is more complex. Electronics manufacturing is more heavily reliant on out‑sourcing. The ESD industry seems to have jumped into this swirling eddy headfirst. ESD control programs have mushroomed. Black has been replaced by green, blue and gold. Shielding bags dominate the warehouse. Ionizers exist along side wrist straps and ground cords. An early history of “smoke and mirrors,” magic and lofty claims of performance is rapidly and safely being relegated to the past.

In the rush to complete RF immunity testing on schedule, it is not all that unusual to overlook inherent test equipment limitations. While some test equipment characteristics such as power amplifier harmonics are obviously a limiting factor, the broadband characteristics of antennas, directional couplers, power meters and isotropic field probes can hardly be considered a limitation for most applications. However, when used with power amplifiers exhibiting significant harmonic distortion in Immunity test systems, the broadband characteristics of these devices can result in measurement uncertainty and unacceptable errors.