Solid-State Circuit Protection for Hazardous DC Lighting Loads
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Solution Overview
Problem
Conventional circuit protection devices for DC loads, such as LED luminaires, are prone to reliability issues and high costs due to integrated power converting circuitry, and they pose ignition risks in hazardous environments, necessitating expensive explosion-proof enclosures that increase installation and maintenance complexity.
Innovation Solution
A circuit protection device with integrated load controller and power converting circuitry that outputs controlled DC power to connected LED luminaires, eliminating the need for internal converters and providing circuit protection, while using solid state switches to prevent ignition sources, thus allowing compliance with hazardous location standards without separate explosion-proof enclosures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If integrated power converting circuitry is included in each LED luminaire, then the device can operate independently, but manufacturing costs and device complexity increase
Solution Approach 1:
The power converting circuitry is extracted from individual LED luminaires and consolidated into a separate circuit protection device. This extraction reduces the complexity and cost of each luminaire while maintaining the ability to provide controlled DC power to multiple series-connected loads.
Solution Approach 2:
The circuit protection device is designed to serve multiple functions: it provides circuit protection, power conversion from AC to DC, and controlled power distribution to multiple LED luminaires. This multi-functionality eliminates the need for each luminaire to have its own integrated converter.
2Use of energy by moving object
If integrated power converting circuitry is included in each LED luminaire, then the device can convert AC to DC, but manufacturing costs increase
Solution Approach 1:
Multiple power conversion functions are merged into a single circuit protection device that serves multiple series-connected LED luminaires. This consolidation reduces the total number of power converters needed, lowering manufacturing costs while maintaining AC to DC conversion capability for all connected loads.
3Reliability
If conventional circuit protection devices are used in hazardous locations, then circuit protection is provided, but ignition risks exist requiring explosion-proof enclosures
Solution Approach 1:
The patent replaces conventional mechanical circuit breakers with solid-state switching elements. This substitution eliminates mechanical contacts that could create sparks or arcs, thereby removing the ignition hazard while maintaining circuit protection functionality in hazardous locations.
4Object-affected harmful factors
If explosion-proof enclosures are used for hazardous location compliance, then safety standards are met, but installation and maintenance complexity increase
Solution Approach 1:
By replacing mechanical switching components with solid-state elements, the patent eliminates the need for explosion-proof enclosures. This substitution inherently prevents ignition sources without requiring additional protective housing, thereby simplifying installation and maintenance while maintaining safety compliance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces manufacturing costs, simplifies installation, and enhances reliability by eliminating internal converters and avoiding ignition risks, while meeting safety standards for hazardous locations, thereby reducing space and maintenance complexity.
Implementation Method 1
a load controller having power converting circuity that converts an AC power supply input to a DC power output
Implementation Method 2
at least one solid state switching element operable in an arc-free manner to limit or preclude electrical current flow
Data Source
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AI summary
Hazardous location compliant solid state circuit protection device (100) includes at least one solid state switching element (142a-d) and a load controller (170). The solid state switching element operates in an arc-free manner to limit or preclude electrical current flow from the line-side terminal (132) to the load-side terminal (136). The load controller includes power converter circuitry (172) operative to convert an alternating current (AC) power supply input to the line- side terminal to a direct current (DC) power output at the load side terminal. One or more DC devices may be coupled to the DC power output at the load side terminal.