Patent · US Expired

Electric control apparatus

US5874873A · kind A · utility

2Cited by
4References
31Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 22, 1997
Grant dateFeb 23, 1999
Priority date
Expiry dateAug 22, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01H77/108
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An electric motor control apparatus includes an electrical current control apparatus which is operable to limit current to an electric motor. When the electric motor is a three-phase motor, three current limiting switch assemblies are provided in the electric current control apparatus. A single stack of laminations concentrates magnetic fields emanating from conductors in all three current limiting switch assemblies. Each of the current limiting switch assemblies includes two movable contacts which are mounted on contact arms. The contact arms are movable in slots in the stack of laminations. A first series of splitter plates is disposed in an array along a path of movement of the contact on the first movable contact arm and a second series of splitter plates is disposed along a path of movement of the contact on the second contact arm for each of the current limiting switch assemblies. A short circuit splitter plate conducts electrical current between the two series of splitter plates. A bypass splitter plate is connected in a bypass circuit which conducts excessive current around a motor starter to protect the motor starter.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.