I was discussing UL 1950/CSA950/EN60950 clause 2.11, Limited Power
Source with a colleague, and we were looking at the Table 9 limits for
maximum output current Isc (1000/Uoc) and maximum VA (250). If Uoc is
20V, then Isc is 1000/20 = 50A max. However, 20V X 50A = 1000VA.
It seems like if the maximum allowable VA is 250 and Uoc is 20V, then
the maximum current is limited to 250/20 = 12.5A.
I probably can't see the forest for the trees, but unfortunately my
brain is supplied by a limited power source. Any comments as to why
there is my perceived discrepancy between Isc and max VA would be
appreciated.
Just Wonderin',
Kendall Wilcox
Manager, Regulatory Engineering
Fujitsu Computer Products of America
[email protected]
