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This FAQ has been written for NEAL (North East Africa and Levant) region. If you are looking for information for another region, please select the correct country from the top-left dropdown in the page and 'Navigate to Browse FAQs' in the Support menu.

What is the definition of ANSI 50N/51N or 50G/51G - Earth fault?

Earth fault protection based on measured or calculated residual current values:

ANSI 50N/51N: residual current calculated or measured by 3 phase current sensors
ANSI 50G/51G: residual current measured directly by a specific sensor.