Contactor Latching Block for Zero-Power Hold and Safe Power Loss Release
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Solution Overview
Problem
Conventional contactors for industrial loads require constant power to maintain the ON state, leading to unnecessary power consumption and potential unexpected starts upon line power restoration, while mechanically latched contactors in lighting applications lack safety features.
Innovation Solution
An electrical contactor system with a latching block that includes a latch member and power storage, allowing the contactor to maintain the closed position without power consumption and preventing unexpected starts by using stored power to unlatch upon line power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If constant power is supplied to maintain contactor in ON state, then safety against unexpected start is improved, but power consumption increases
Solution Approach 1:
The controller detects line power loss and actuates the latch member to the unlatched position before line power is restored, preventing unexpected start. This preliminary action eliminates the need for continuous power monitoring and maintains safety without constant power consumption.
Solution Approach 2:
The patent replaces the electrical holding mechanism (continuous power to contact actuator) with a mechanical latching mechanism. The latch member mechanically maintains the contactor in the ON state without requiring continuous electrical power, thereby reducing power consumption while maintaining operational state.
2Use of energy by moving object
If mechanical latching is used to reduce power consumption, then power consumption is reduced, but safety feature is lost
Solution Approach 1:
The patent merges the mechanical latching mechanism with an electrical control system. The controller monitors line power status and actuates the latch member electrically when needed, combining the low power consumption of mechanical latching with the safety monitoring capability of an electrical control system.
Solution Approach 2:
The system uses the available line power to charge a capacitor that automatically actuates the latch member upon power loss detection. This self-service mechanism eliminates the need for continuous external power supply while maintaining safety functionality through automatic response to power disturbances.
3Loss of energy
If line power is lost and contacts remain latched in ON position, then power consumption is reduced during normal operation, but unexpected start occurs when line power is restored
Solution Approach 1:
The controller detects line power loss and proactively actuates the latch member to the unlatched position before line power restoration occurs. This preliminary action prevents the harmful effect of unexpected start while maintaining energy efficiency during normal operation by using mechanical latching rather than continuous electrical holding.
Data Source
AI summary
A system includes an electrical contactor that is biased to the open circuit position. A latching block includes a latch member operatively connected to a latch actuator. The latch actuator is configured to actuate to a latched position mechanically blocking movement of the electrical contactor from the closed circuit position to the open circuit position, and to an unlatched position allowing free movement of the electrical contactor back and forth between the open and closed positions. The latch member maintains latching of the electrical contactor in the closed circuit position without need for power consumption by the contact actuator or the latch actuator. The latching block includes a power storage for actuating the latch member from the latched position to the unlatched position in the event of loss of line power to prevent unexpected start of a load after line power is restored.