An MCB (miniature circuit breaker) protects electrical circuits from overloading conditions and short circuits. If the MCB is not tripped but there is no power, it shows that there is an issue with the circuit that the MCB is protecting. There are some causes why your MCB is not tripped but there is no power: a circuit is overloaded. short Molded case circuit breakers use is restricted to low voltage and medium voltage systems. With alternating current (AC), this breaker provides high interrupting capacity for short circuits in minimum space. On AC or direct current (DC) systems, this breaker is often the first protection device to handle electrical problems. Reset the Tripped Breaker. Photo: LSOphoto / iStock / Getty Images Plus / Getty Images. To reset the breaker, move the switch into the “on” position to restore power. If the breaker switch is in the middle position, you should first move it to the “off” position before flipping it back up to “on.”. Occasionally, a breaker box can A circuit overload is one of the main reasons for constantly tripped circuit breakers. This occurs when you want a particular circuit to provide more electricity than its actual capacity. This will lead to overheating the circuit, which puts all the electrical appliances connected to the circuit at risk. Types of MCB based on Poles. A single-pole (1P) MCB provides switching and protection only for one single phase of supply. A two-pole (2P) provides switching and protection for both phase and neutral. A three-pole (3P) MCB provides switching and protection only to three phases and not neutral. The air circuit breaker carries an air brake principle that is used in ac and dc circuits for up to 12KV. This breaker is used in an electricity sharing system. They also carry high resistance power that helps in increasing the resistance of the arc by the method of lengthening, cooling, and splitting. If you see frozen coils or suspect some system component is frozen over, turn off your HVAC unit from the circuit breaker. This will give your system a chance to defrost and reset. If the system There are varieties current ratings MCCB for the same series frame Size. For example, DX100 Frame Size MCCB for rated current of 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A, 100A. Same DX225 Frame Size the magnetic starter is actually a thermal overload device. this function is now replaced by MCB ya its recommended to have isolator so you can switch off the ac for maintenance. 3.5hp running amp is 16.2 (according to daikin) so 20A MCB may not be enough. check the label on your aircond for the running amp. you may need to use 32A MCB for each aircond. check your main fuse and main MCB so not A circuit breaker is a safety device that shuts off when there's a current surge. Two-pole breakers control circuits for large appliances. A two-pole breaker consists of two breakers. Each one connects to one of the hot bus bars in the panel, which makes the voltage of the circuit 240 volts. 9IqH.