Distributed Overcurrent Protection in Low Voltage Building Installations

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Solution Overview

Problem

Centralized arrangements of overcurrent protective devices in low-voltage building installations lead to high costs, complex planning, and difficulties in expansion due to parallel conductor configurations, which are both expensive and inefficient.

Innovation Solution

A distributed arrangement of overcurrent protective devices along line branches with reduced cross-sections, allowing for remote-controlled reactivation and local interruption based on overcurrent detection, eliminating the need for a centralized switch cabinet and reducing parallelism in conductor configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If overcurrent protective devices are arranged in a centralized switch cabinet, then overcurrent protection is provided for all circuits, but the installation costs increase and planning becomes more complex due to parallel conductor configurations

Engineering Contradiction:
Improveovercurrent protectionVSAvoidinstallation planning
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the centralized overcurrent protection system into distributed protection devices located at individual circuit outlets. Each protective device is segmented as an independent unit that can be installed separately, eliminating the need for a centralized switch cabinet and reducing installation planning complexity while maintaining comprehensive overcurrent protection across all circuits

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the overcurrent protection function from the centralized switch cabinet and relocates it to individual protective devices installed at circuit outlets. This extraction removes the requirement for parallel conductor configurations and reduces installation complexity while preserving the essential overcurrent protection capability for each circuit

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If a centralized switch cabinet is used for overcurrent protection, then all circuits are protected, but expansion becomes more difficult due to fixed parallel conductor arrangements

Engineering Contradiction:
Improveovercurrent protectionVSAvoidsystem expansion
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

By segmenting the protection system into independent distributed devices at each outlet, the patent enables flexible addition of new circuits without being constrained by fixed parallel conductor arrangements. New circuits can be independently installed and protected without affecting existing circuits, facilitating easier system expansion

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a dynamic system where protective devices can be independently added, removed, or modified at individual circuit locations. This dynamic architecture allows the electrical installation to adapt to changing requirements and expand more easily compared to rigid centralized systems

Inventive Principle:
Principle #15Dynamics

3Device complexity

If distributed overcurrent protective devices are used with remote control, then installation costs are reduced and planning is simplified, but the system may fail to provide protection if remote control is unavailable

Engineering Contradiction:
Improveinstallation planningVSAvoidovercurrent protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The distributed overcurrent protective devices are designed to autonomously detect and respond to overcurrent conditions without requiring external remote control signals. Each device independently monitors its own circuit and automatically interrupts protection when needed, ensuring reliable operation even when remote control systems are unavailable or fail

Inventive Principle:
Principle #25Self-service

4Reliability

If centralized overcurrent protective devices are used, then comprehensive protection is achieved, but the parallel conductor configurations increase material costs

Engineering Contradiction:
Improveovercurrent protectionVSAvoidconductor material
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts protection devices from the centralized location and places them at individual circuit outlets, eliminating the need for long parallel conductor runs to a central switch cabinet. This reduces the total quantity of conductor material required while maintaining comprehensive overcurrent protection for all circuits

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2375526B1Electric low voltage building installation
Publication Date: 2016.06.08 WOERTZ
  • EP2375526B1 patent drawingFigure 1~6
  • EP2375526B1 patent drawingFigure 2
  • EP2375526B1 patent drawingFigure 3

AI summary

A low-voltage electrical building installation, in which overcurrent protective devices are provided for branch circuits with reduced cross-sections, has at least one distribution line (13) from which branch circuits (12) leading to sub-lines (14) with a reduced cross-section compared to the distribution line (13) are distributed throughout the building. Accordingly, the associated overcurrent protective devices (15) are distributed at the branch circuits (12) or – downstream of the branch circuits (12) – in the sub-lines (14). The distributed overcurrent protective devices (15) can be reset remotely after tripping. The overcurrent protective devices (15) do not require a remote control function to interrupt their respective branch circuit (12) or sub-line (14), but rather initiate the interruption locally, i.e., based on their own detection of an overcurrent.