Are the trip curves for a TM-D trip unit on a NS legacy circuit breaker the same as the curves for a TM-D trip unit on a NSX circuit breaker?


29 September 2021

The tripping curve are same between NS100-250 legacy (AC range) equipped with TM-D trip unit and NSX100-250 (AC range) equipped TM-D trip unit on the basis of same rating. Except for the TM63D.
For continuous improvement purpose, the continuous engineering has modified the principle of the thermal function, by changing the direct heating effect by indirect heating effect of the sub-assembly realizing the thermal function. In consequence the curve for TM63D has changed. From catalogue Compact NSX 2011 the new curve is available.
This tripping curve for TM63D is significantly different between legacy NS and NSX.