Fire-Resistant Electrical Box With Intumescent Sealing

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Solution Overview

Problem

Mounting electrical boxes on fire-resistant walls compromises the one-hour fire rating, leading contractors to relocate them to non-fire-resistant walls, as any hole cut into the wall affects fire containment.

Innovation Solution

A recessed, wall-mounted fire-resistant electrical box with heat-activated intumescent material is designed to maintain the one-hour fire rating by sealing openings and providing venting and cable exits, ensuring the intumescent material is evenly distributed and accessible.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If electrical boxes are mounted on fire-resistant walls, then electrical设备安装 is enabled, but the fire rating of the wall is compromised

Engineering Contradiction:

Improveelectrical设备安装VSAvoidfire rating

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies intumescent material that remains inactive during normal operation (allowing electrical设备安装) but activates during fire conditions (restoring fire rating). This converts the harmful effect of wall penetrations into a beneficial fire-protection mechanism that only activates when needed.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The intumescent material changes its physical parameters (expands and seals) in response to temperature changes. During normal conditions, the material maintains a compact state allowing electrical设备安装, but under fire conditions, it expands to seal openings and maintain the fire rating.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If holes are cut into fire-resistant walls for electrical boxes, then electrical设备安装 is enabled, but fire containment capability deteriorates

Engineering Contradiction:

Improveelectrical设备安装VSAvoidfire containment

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of wall penetrations (compromising fire containment) into a beneficial fire-protection mechanism. The intumescent material seals the penetration openings when activated by heat, transforming the vulnerability created by electrical设备安装 into a protective feature that maintains fire containment.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The intumescent material is pre-installed in the electrical box to counteract the fire containment vulnerability before a fire event occurs. When heat is detected, the material activates to seal openings, providing preliminary protection against fire spread through the wall penetration.

Inventive Principle:

Principle #9Preliminary anti-action

3Reliability

If intumescent material is added to seal openings, then fire rating is maintained, but device complexity increases

Engineering Contradiction:

Improvefire ratingVSAvoidelectrical box structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the intumescent fire-protection material with the electrical box structure itself, integrating the fire-protection function into the existing device rather than adding separate components. This reduces overall system complexity while maintaining fire rating.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The electrical box utilizes composite construction incorporating intumescent material into the box structure. This composite approach combines the structural function of the electrical box with the fire-protection function of the intumescent material, achieving fire rating maintenance without significantly increasing device complexity.

Inventive Principle:

Principle #40Composite materials

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

The solution allows for the installation of electrical and audio-visual devices within fire-resistant walls without compromising the fire rating, ensuring the integrity of the wall's fire resistance while allowing for wiring and cable access.

Implementation Method 1

heat activated intumescent fire-resistant material, which maintains the one-hour fire rating of the wall

Methodology Applied

Scientific EffectIntumescent material expansion: Intumescent Materials

Implementation Method 2

intumescent material between at least a portion of the outer back panel and the inner back panel

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9806509B1Fire-resistant electrical box

Publication Date: 2017.10.31 FSR

AI summary

A fire-resistant electrical box assembly includes an outer box assembly having an outer top panel, an outer bottom panel, an outer first side panel, an outer second side panel, an outer back panel, an inner back panel, and a front panel forming an opening substantially covered by a front cover, an inner box assembly having one or more of an inner top panel, an inner bottom panel, an inner first side panel, and an inner second side panel, and an intumescent material between at least a portion of the outer back panel and the inner back panel.