Relay with core conductor and current sensing
AssigneeInternational Controls and Measurements Corporation
InventorHassan B. Kadah
Life of this patent
Estimating the term…
Abstract
A relay situated in series between an AC line source and an AC load has a core conductor connected with the fixed N.O. contact, so that load current flows axially through the core of the actuator coil. Alternatively, the fixed N.C. contact may be connected with the core conductor. A plate armature with leaf springs can achieve linear axial action. A sensor connected to leads of a winding of the actuator coil picks up a an induced voltage that is representative of the current supplied to the load. This provides a simple arrangement for monitoring for current level and can be used for measuring power factor or ΔΦ at the load device. In a three phase embodiment, phase imbalance can be detected.
Claims20
An electromechanical relay adapted to be situated in series with a source of AC power and an AC load, the relay comprising an actuator coil to which an actuator current is controllably applied for closing and releasing a contactor armature of the relay, the contactor armature including means normally biasing the contactor armature away from the actuator coil and a first electrical contact carried on said contactor member;
- a second electrical contact adapted to make contact with said first contact when the actuator coil is in a state that is either moved towards said contactor armature, or is biased away from the contactor armature, the second contact being connected to a core conductor that passes through an axial bore of said actuator coil, the core conductor carrying load current to said AC load when said actuator coil closes said contactor armature;
- and a load current sensor having input terminals connected to a winding of said actuator coil for picking up an induced voltage representative of the load current carried on said core conductor.
Dependencies are inferred from the claim text.