pair of shelves 86 87 that are formed within the cover side walls 12a 12b when the accessory cover 13 is removed from the integrated circuit breaker cover 12 and the actuator accessory unit 29 is removed from the actuator accessory recess 30 the trip actuator latch 36 which is pivotally attached to the actuator accessory unit housing 31 by means of pivot pin 37 lifts away from latch support arm 60 which is retained within the recess 30 in the circuit breaker cover as best seen in fig3 and 4 such that the latch pin 61 is freed from the hook 42 and immediately moves to its 34 tripped 34 position under the urgence of the trip spring 62 to articulate the integrated circuit breaker operating mechanism and separate the circuit breaker contacts when undervoltage release function is not required a simple combined actuator accessory unit is employed similar to that described within aformentioned u s pat no 4 700 161 which includes a permanent magnet seated behind the actuator accessory coil 32 as shown earlier in phantom at 89 in fig4 this allows the combined trip actuator accessory unit 29 to respond to overcurrent conditions and provide shunt trip facility without requiring the energizing of the actuator accessory coil the holding force for the armature 33 during the reset function then being supplied by the permanent magnet the circuits for providing undervoltage shunt trip and overcurrent facility to a single actuator accessory coil 32 are found within the aforementioned u s patent application ser no 133 869 once the trip unit printed.