The CBEMA curve was first created in the 1970’s by the Computer Business Equipment Manufacturer’s Association. It is the result of accumulation of operational data from mainframe computers. From that, this curve was projected as a standard for all electronic data prcessing equipment.
In the 1990’s the Information Technology Industry Council (ITIC) was formed as an offshoot of CBEMA to update the curve because of the proliferation of non-mainframe computing devices that emerged with client-server and personal computing. ITIC built the updates mainly for then new, personal computers.
Through the past 30 years, this curve grew from describing mainframe computer power quality susceptibility to define the power quality susceptibility for all data processing equipment.
The figure shows the CBEMA and ITIC curves superimposed. The differences can be said to be rather subtle. But the question we ask is this:
Are these curves, which were created in the 1970’s and 1990’s relevant to dat processing equipment in the data center today? We assume them in data center applications, but do they really apply? How do these compare to our real world experiences today? What is Power quality susceptibility really like for modern data processing equipment?
By Bob Landstrom
(This is Part-3 of a 9-part series on a modern assessment of the ITIC/CBEMA power quality susceptibility curve)