A manual opening mechanism for use with an isolation switch of a circuit interrupter is fully integrated into the circuit interrupter. The manual opening mechanism includes a rotating handle that is accessible from the front panel of the circuit interrupter. Rotating the handle applies force to the centerline of the isolation switch drive shaft, which prevents uneven loading and thus optimizes robustness during manual opening of the isolation switch. In addition, the handle has an ergonomic design, and is proportioned to minimize the force that an operator must apply to the handle in order to open the isolation switch.