Investigation of thermal and mechanical stresses of arcing contacts in circuit breakers

The tulip contact is one of the elements which constitute arcing contacts in a circuit breaker. This element plays an important role in breaking of fault currents (short circuit currents). Loss of contact force or/and opening of contact fingers can happen during short circuit test if certain parameters are not considered in the design of the tulip. In this article, we analyse thermal and mechanical parameters which influence the quality of arcing. Results of experiments and calculations have been compared and recommendations are made to improve arcing contact design.