In the normal condition, current flows though the arm terminal, down through the very low resistance contact point and out through the base terminal. The mini-breaker can be triggered from either an increase in the environmental temperature or from excessive current flows. Once the trip temperature has been reached, the bi-metal disc heats and flexes and this motion causes the arm to open. If the mini-breaker only used a bi-metal disc for its protection, the arm would quickly close as temperature cooled. However, key to the mini-breaker design is the PTC chip that operates in parallel with the arm terminal. When the bi-metal disc causes the arm to open, current flows though the bi-metal disc and into the PTC chip. This current causes the PTC chip to act like a current limiting heater which provides sufficient heat to keep the bi-metal disc flexed and the arm open. The combination of the bi-metal disc and the PTC chip prevents oscillating opening and closing of the mini-breaker arm and instead allows the arm to reset at lower and safer temperature levels of between 40°C and 10°C below the lower specification limit of the mini-breaker. As part of its UL 60730 testing, most mini-breakers are tested to up to 6000 cycles of this opening and closing mechanism.