Glossary J

J - Terms

J SECONDS (DC Motors)
J is the per unit moment of inertia. It is defined as the time in seconds to accelerate the motor armature to rated base speed using rated full load torque.

J = WR2x Base Rpm(seconds)
  ----------------------------
  308 x Rated Torque



JACKSCREW
A device used for leveling the positioning of a motor. These devices are adjustable screws fitting on the base or motor frame. Also a device for removing endshields from a motor assembly.