Multipole electromechanical switching device

Patent metadata

Field	Value
Publication number	US-9805883-B2
Application number	US-201615214142-A
Country	US
Kind code	B2
Filing date	Jul 19, 2016
Priority date	Mar 15, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A method and apparatus using electromagnetic switching in a two-step connection process is provided to minimize surge currents and torque oscillations in three-phase motors during starts.

First claim

What is claimed is:

1. A method of switching electrical contacts comprising:
monitoring voltage in an electrical system having a power source and a load;
closing first and second direct current electromagnetically controlled contacts for first and second phases of electrical power at or before a first phase angle determined based on voltage zero-crossing; and
thereafter closing third direct current electromagnetically controlled contacts for a third phase of electrical power at a prescribed moment following the closing of the first direct current electromagnetically controlled contacts;
wherein the first, second, and third electromagnetically controlled contacts are provided in windows of a common carrier and the window in which the third direct current electromagnetically controlled contacts are disposed is offset with respect to the windows in which the first and second direct current electromagnetically controlled contacts are disposed to provide the closure of the first and second direct current electromagnetically controlled contacts before the closure of the third direct current electromagnetically controlled contacts.

Assignees

• Rockwell Automation Tech Inc

Inventors

• Kinsella James J
• Wieloch Christopher J

Classifications

• H01H50/90

  the delay effective in both directions of operation · CPC title

• H01H50/546

  for contactors having bridging contacts · CPC title

• H01H9/563 Primary

  for multipolar switches, e.g. different timing for different phases, selecting phase with first zero-crossing · CPC title

• H01H1/2016

  in which the two contact pairs commutate at substantially different moments · CPC title

• H01H50/54

  Contact arrangements · CPC title