Arc Plenum Mounting Base for Switchgear Fault Gas Channeling
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Solution Overview
Problem
Low voltage switchgear enclosures are vulnerable to damage and operator safety is compromised during internal arcing faults, as hot decomposition products and plasma are not effectively channeled away from the front, sides, and rear of the equipment, posing a risk of injury and equipment damage.
Innovation Solution
A mounting base with an integrated arc plenum that channels hot arc gases from the front compartments to the rear compartment, where they are safely discharged through the roof of the switchgear apparatus, utilizing a middle support baffle to create a passage for arc gases from the front to the rear plenum opening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard metal-enclosed switchgear is used to withstand bolted faults, then the enclosure can handle short-circuit currents, but it is vulnerable to damage during internal arcing faults because hot decomposition products and plasma are not effectively channeled away
Solution Approach 1:
The switchgear enclosure is segmented into distinct zones: a front compartment for equipment, a rear compartment for cable routing, and an integrated arc plenum space between them. The middle support baffle divides the plenum into front and rear plenum openings, creating controlled pathways for plasma flow. This segmentation allows the enclosure to handle bolted faults while directing arcing fault products away from personnel areas.
Solution Approach 2:
The arc plenum acts as an intermediary chamber between the front and rear compartments. When an internal arc occurs, the plenum captures hot decomposition products and plasma, channeling them through the middle support baffle opening to the rear compartment. This intermediary space prevents direct discharge of harmful factors to the front where personnel operate, while still allowing the enclosure to withstand bolted faults.
2Object-affected harmful factors
If the switchgear enclosure is designed to contain internal arcs, then operator safety is improved, but the device complexity increases due to the need for integrated arc plenum and ventilation systems
Solution Approach 1:
The arc plenum is merged with the mounting base structure, integrating the arc containment function into the existing enclosure framework. The middle support baffle serves dual purposes: it provides structural support and creates the plenum openings for plasma channeling. This merging approach improves operator safety while minimizing the increase in device complexity by utilizing existing structural elements.
Solution Approach 2:
The rear compartment serves multiple functions: it acts as a receptacle for cable routing, provides a pathway for plasma discharge from the arc plenum, and serves as a ventilation channel to safely exhaust hot gases from the rear of the enclosure. This multi-functionality improves operator safety without requiring additional dedicated components, thereby limiting the increase in device complexity.
3Ease of operation
If a mounting base is added to elevate the switchgear off the floor, then ease of installation and maintenance is improved, but the device complexity increases
Solution Approach 1:
The mounting base is merged with the arc plenum structure, combining the elevation function with the arc containment function. The mounting base forms the bottom boundary of the plenum, creating a unified structure that both elevates the switchgear for easier installation and maintenance, and contains arcs by directing plasma through the middle support baffle to the rear compartment.
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 effectively channels and discharges hot arc gases and particulates away from personnel and equipment, enhancing operator safety and preventing damage to the switchgear enclosure during arcing faults, while also providing a means to elevate the switchgear off the floor using a mounting base.
Implementation Method 1
The switchgear mounting base works in conjunction with a ventilation system in the switchgear apparatus to channel hot arc gasses (plasma) from the lower breaker compartments in the front of the switchgear in the event of an internal arcing fault
Implementation Method 2
The energy resulting from an internal arc in air causes a sudden pressure and temperature increase inside the enclosure
Implementation Method 3
at least one middle support baffle connecting said first side wall to said second side wall within said central open area, and forming a first arc plenum opening and a second arc plenum opening
Implementation Method 4
The occurrence of an arcing fault inside the switchgear produces physical phenomena that are different from bolted faults. For example, the energy resulting from an internal arc in air causes a sudden pressure and temperature increase inside the enclosure
Data Source
AI summary
The present invention relates generally to a switchgear apparatus. More particularly, the invention encompasses a mounting base with arc plenum for a switchgear apparatus. The present invention also relates to enclosures for switchgear, panel boards, circuit breakers, and more particularly to an enclosure for low voltage switchgear and switchboard assemblies. The enclosure can be a walk-in type enclosure or a non-walk-in type enclosure. This invention further provides a method and apparatus for channeling plasma (hot arc gasses) that are generated from an arc. The switchgear mounting base with internal arc plenum can be an integral part of an arc resistant switchgear assembly and is preferably located under the switchgear. The switchgear mounting base works in conjunction with a ventilation system in the switchgear apparatus to channel hot arc gasses (plasma) from the lower breaker compartments in the front of the switchgear in the event of an internal arcing fault in one of the breaker compartments. The hot arc gasses exit downward from the bottom of the switchgear and into the plenum. The gasses then are channeled to travel backward through the plenum and then up again into the switchgear rear compartment where they can be routed to and safely discharged from the roof of the switchgear apparatus.