UL-1950: an IEC-950-based US standard for information technology equipment including electrical business equipment

Because the market for computers, their peripherals, and other electrical business machines has become worldwide, manufacturers have expressed a need that International Safety Standard IEC-950 be adopted as the US national safety standard for their products. Outright adoption of IEC-950 was not feasible for the United States because of conflicts with the National Electrical Code. Therefore, a committee of industry and safety engineers developed a safety standard that was as close to IEC-950 as possible but compatible with the NEC. The result of the committee´s work, UL-1950, represents a change in requirements for safety of computer and electrical business machines. Many machines will need to be reevaluated to obtain listing to the upgrading requirements of the standard. Most of the requirements of UL-1950 that differ from predecessor standards are associated with the risk of electric shock. The author deals with the technicalities of those new requirements