A shunt trip device for a circuit breaker having a trip bar for tripping the circuit breaker. The device includes a housing having a slot and a bottom wall having a pivot pocket. The device also includes a lever arm having a lever projection portion and a pivot portion. The pivot portion is located in the pivot pocket to enable rotation of the lever arm in the slot about a lever rotation axis between first and second positions. When the lever arm is in the second position, the lever projection portion moves the trip bar and trips the circuit breaker. The device further includes an actuation device that moves the lever arm to the second position. The pivot portion and pivot pocket form a configuration that increases a perpendicular distance between a force generated by the actuation device and the lever rotation axis.