Overload Current

•Overload current is greater in magnitude than full-load current and flows only in the normal circuit path.

 It is commonly caused by

•- overloaded equipment,

•- single-phasing, or

•- low line voltage,

•Overload current is considered to be an abnormal current. Some overload currents, such as motor starting currents, are only temporary, however, and are treated as normal currents. Motor starting current is a function of the motor design and may be as much as twenty times full-load current in extreme cases.

•Motor starting current is called locked-rotor current and is included on the motor nameplate as

LRA (Locked-Rotor Amperes).

•Overload current, then, is greater in magnitude than full-load amperes but less than locked-rotor amperes and flows only in the normal circuit path.