If you find an open rotor bar in a motor that seemed to be running ok, is it ok to bypass repair until the motor's next refurbishment? The conservative answer is no.

When one bar is open, the bars around it and under the same magnetic pole must carry the additional current that the open bar no longer carries. Now, you're probably dealing with increased slip, reduced torque, increased temperature in surrounding bars, etc.

One open bar will lead to more open bars and eventually to motor failure. Protect your other components and schedule the repair.