CT/PT Class Comparison: USA vs Europe

TYPE

USA CLASSIFICATIONS (ANSI/IEEE)

EUROPEAN CLASSIFICATIONS (IEC)

CT

0.3, 0.6, 1.2, C200, C400

0.1, 0.2, 0.5, 1, 3, 5 (IEC 61869-2)

PT

0.3, 0.6, 1.2

0.1, 0.2, 0.5, 1 (IEC 61869-3)
NOTE: Classes in US are burden and accuracy-based (e.g., C100, B0.5). IEC defines class by % error at rated burden; not directly equivalent to US.