A full‐converter fed DC drive with only few damaged thyristors can still be operated under partial load with deteriorated performance. Through the investigation on the operating characteristics, this paper provides a guidance to the temporary use of faulty DC drives. All possible fault cases are categorized into nine representative modes. For each mode, the switching functions of the power switches are derived for calculating the output voltage waveforms of the faulty converter. By applying these waveforms to the DC machine, torque‐speed characteristics of each mode are obtained. The calculated converter output waveforms are experimentally verified on a 10‐Hp DC drive.