The paper mainly introduces the principles to calculate the settings of unbalanced current protection for H-configured capacitor banks. The basic principles of the permitted detuning of the filter banks and the withstand voltages on remaining perfect capacitor units after some units’ failures are proposed. Mathematical analysis of elements failures or short circuit of H capacitor banks is made together with detuning and overvoltage respectively. Combining with different fault property of both the internal fused and fuseless capacitors, the setting calculation analysis method of capacitor bank unbalanced protection and final formulations of setting calculation are given. The paper constitutes the basis for the unbalanced protection of H-configured capacitor banks.