CBEMA / ITIC curve (50 Hz)

[MissMe]

As far as I know, original CBEMA/ITIC curve is used for equipment with rated voltage 120 V and frequency 60 Hz. Can I apply this curve on equipment rated 230 V/50 Hz as the values are given in percentage? Or is there another version of this curve that is ment fo 50 Hz equipment?
Tnx.

 

[alehman]

I haven't seen a 50Hz version. Fundamentally, I can't think of any reason it would be different than for 60Hz.

 

[xabproject]

Dear MissMe,
Hers is a brief on the curve. See the reference to one mains cycle of 20ms meaning the graph is equally applicable to 50Hz systems!
best regards,

The Information Technology Industry Council (ITIC) curve, formerly known as the Computer and Business Equipment manufacturers Association (CBEMA) curve, describes the tolerance of equipment to voltage disturbances of all types.
The solid lines represent the maximum and minimum voltages that can be tolerated without malfunction plotted against time. For example, data processing equipment should tolerate an over-voltage of five times nominal supply for a duration of 100 ?s but only 20 % over-voltage for 10 ms. On the under voltage side, a complete loss of supply should be tolerated for up to 20 ms (one mains cycle) but for 100 ms the minimum retained voltage must be 70 % of nominal. The curve was originally produced to help users of IT equipment in resolving power quality problems with electricity suppliers. By standardising the requirements of equipment it became much easier to determine by
site measurement whether the supply was adequate or not.

 

[stevenal]

http://www.itic.org/technical/iticurv.pdf

"2) APPLICABILITY
The Curve and this Application Note are applicable to 120V nominal voltages obtained from 120V,
208Y/120V, and 120/240V 60Hz systems. Other nominal voltages and frequencies are not specifically
considered and it is the responsibility of the user to determine the applicability of these documents for such
conditions."

And since the time axis is calibrated in both seconds and cycles, which one shall we choose when applying it to 50 hz?. 20 ms is more than 1 cycle on their graph.

 

[alehman]

Loads care about the duration of disruption, not what percetange of a cycle is disrupted.