Patent ID: 6359440
Filing Date: 2002-03-19
Classification: H01H

Abstract:
A method for determining a remaining lifetime value of contacts in a switchgear, comprising the steps of:determining a contact spring action at a contact gap; during a shutdown cycle, measuring each change in the contact spring action to determine a contact erosion, including the steps of measuring a run-time value of an armature path from a first start of an armature movement in a contactor solenoid actuator to a second start of an opening of at least one of the contacts, the measuring step being performed on a load side of the switchgear, the first start of the armature being determined by a voltageless signaling of a start of the armature movement, determining a path length as a function of the run-time value, and determining the change in contact spring action by a change in the path length; determining an erosion of at least one of the contacts as a function of the change in the contact spring action; and determining the remaining lifetime value of the at least one of the contacts as a function of the erosion.