ABB has announced an extension to the S200 Miniature Circuit Breaker (MCB) range with the inclusion of trip curves B, C, D, K and Z.
Many MCB applications utilise the standard C curve tripping characteristic. However, this is not always a suitable protection to apply to the application.
ABB has increased the range of S200 MCBs so that five different tripping characteristics are available across the full range.
The S200 MCB is a product from the Pro M range from ABB System that incorporates standard short circuit capacities of 6kA, 10kA and 15-25kA. This new announcement provides trip curves across all sizes and capacities.
In applications where long cable runs need protection, the B curve will provide the required level of protection. The C curve is considered a general purpose protection curve for many light and power applications. For motor starting and transformer protection applications, the D curve is often utilised due to the high inrush or start-up currents of this type of load.
ABB also provides the K curve characteristic for motor starting and transformer loads as this curve will offer strong protection to these circuits due to its better thermal characteristics (1.05 to 1.2 times rated current).
In the short circuit range of the K curve, the protection level is 10 to 15 times rated current which also matches the characteristics of most inductive loads more closely than a D curve MCB.
The addition of the Z curve MCB well protects semiconductor electronics due to the instantaneous trip values at 2 to 3 times rated current and the thermal characteristics of 1.05 to 1.2 times rated current.
The inclusion of these additional characteristics has expanded ABB’s already extensive range of MCB solutions for all control circuits and power distribution applications.