A Method for Testing Low Voltage Equipment Against the Cbema Curve

摘要

Much has been written about the "old" Computer Business Equipment Manufacturers Association (CBEMA) Curve, the "new" CBEMA Curve (called the Information Technology Industry Council -ITIC Curve), IEC Voltage immunity testing (IEC 61000-4-11) and other voltage tolerance standards. Additionally, many papers have been written about causes of voltage sags, interruptions, undervoltages, overvoltages and transients. Now that there is an understanding of the recommended limits of input voltage and the reasons why voltage aberrations occur, how do you determine your equipment's tolerance compared to these curves? This paper will discuss a method for performing low voltage testing on a single-phase and three-phase basis to compare your equipment to these voltage limits. This paper will primarily focus on voltage sags and momentary interruptions although methods will be given for testing against overvoltages and transients (these tests can be destructive and are generally performed only by equipment manufacturers).