Contact Resistance Testing and Circuit Breaker Performance

Issue:
Contact resistance testing

Product Line:
Circuit Breakers

Resolution:

While contact resistance testing is intended to be a predictor of breaker thermal performance in service, it is not a design specification and new-breaker contact resistance is subject to wide variation due to factors such as resistive oxidation from the manufacturing process and environmental factors after manufacturing.  The arbitrary standards suggested by NETA and other testing procedures result in many false negatives and should not be relied upon as the sole predictor of breaker thermal performance.

For customers who want to do contact resistance testing, we recommend accepting the breakers that are within the limits acceptable to the customer on the first pass, and for those breakers that are outside those limits on the first pass we recommend referring to the linked product data bulletin (also attached) for further direction. https://download.schneider-electric.com/files?p_enDocType=Data+Bulletin&p_File_Name=0600DB1901.pdf&p_Doc_Ref=0600DB1901

Released for: Schneider Electric Canada