An employee that is transferred or promoted into a different classification or to a different operational unit shall be entitled to work overtime while the employee is a probationary employee in his new classification or assignment providing the employee has been in his new position long enough to be familiar enough with the position and has acquired the ability to perform the duties of the operations that are required to work the overtime. The employee who has been transferred or promoted shall be charged with the average amount of hours and shall be so placed on the overtime rotating list.