This guide presents general recommendations for determining, by approximate methods from nameplate data and by more exact methods from design data, the short-circuit characteristics of direct-current motors and generators. Both methods are applicable to general purpose, general industrial mill motors, and special purpose direct-current machines. This includes constant-speed and adjustable-speed motors and machines with and without compound windings, and with and without compensating windings.

This Guide presents general recommendations for determining, by approximate methods from nameplate data and by more exact methods from design data, the short-circuit characteristics of direct-current motors and generators. Both methods are applicable to General Purpose, General Industrial Mill Motors, and Special Purpose direct-current machines. This includes constant-speed and adjustable-speed motors and machines with and without compound windings, and with and without compensating windings. 1.0.2 This Guide is intended to help those concerned with the transient characteristics of directcurrent machines and direct-current systems and the effects of these tr...

The purpose of this Guide is to:(a) Review the factors that affect the short circuit characteristics of direct-current machinery.(b) Recommend equations for calculating the transient armature and field current from design parameters.(c) Recommend methods for approximating the rate of rise and peak value of armature current from nameplate data. (d) Discuss the causes of flashover and its effect on short-circuit current and effective armature-circuit resistance.