The circuit breaker's instantaneous tripping mechanism serves as a critical protection feature when an electric circuit or equipment experiences a significant overload or short-circuit current. In the case of a near-area short circuit—such as a direct metal-to-metal connection—the short-circuit current can surge to over 20 times the rated current (20In). However, in some cases, reduced insulation resistance due to aging, moisture, or conductive dust may lead to insulation breakdowns that produce overcurrents much lower than those seen in full short circuits. Despite this, these currents can still cause damage to the power distribution system. Therefore, the electromagnetic trip must act quickly and effectively to isolate the faulty circuit.
It is important not to set the instantaneous tripping current too low, as it should avoid unnecessary tripping caused by normal load variations. Typically, the setting should be based on the starting current of the connected load. According to GB14048.2, the adjustable range for instantaneous tripping is generally between 5-10In or 6-12In. As a molded case circuit breaker, it must not only quickly and effectively cut off faulty lines but also coordinate with the overload capacity of the protected equipment to prevent unwanted trips that could disrupt power supply.
The long-time delay function of a molded case circuit breaker is designed to adapt to changes in load conditions and characteristics. This allows users to adjust the settings according to their specific needs, ensuring proper protection without unnecessary interruptions. The long-time delay range is typically wide, often adjustable between 0.4In and 1.0In. Compared to thermomagnetic circuit breakers, electronic trip units offer greater flexibility and broader application potential in modern electrical systems. Solar Street Lights,Solar Powered Street Light,Solar Outdoor Light,Solar Street Light Jiangsu chuanglv Transportation Facilities Co., Ltd , https://www.clsolarlights.com