Significant load changes on the electricity system, resulted it running outside of the stable limit, so that the stability of the system is necessary, because of the problem, in this Final Project required research to get a pararrel-operated or single operated “load sharing” on the optimal generator and not exceeding an electrical power capacity of the unit. The method used in this research is “speed drop” and “ishocronous”, these methods are used to determine the normal limit on the frequency of active load power with a value of 50 Hz + 0,5 Hz and to identify the maximum limit on the power capacity of the generator that runs pararrel with the automated system. And then conducted data retrial at Suralaya power plant (PLTU Suralaya) for 10 (ten) days with the same time with active power load generator unit 1 to unit 4, so that research results obtained from the minimum value to the maximum value, obtained a minimum value of 186,7678 MW with a frequency of 50,4756 Hz and a maximum of 400 MW with a frequency of 49,923 Hz. Finally got the Caracteristic of “load sharing” of each generator which is optimal according to the normal frequency value.