Dielectric Protrusions for Circuit Breaker Debris Isolation
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Solution Overview
Problem
Molded case circuit breakers face issues with debris accumulation due to the limited spacing between the trip unit and the base, leading to a breakdown in the dielectric path during electrical faults, as escaping arc gases cause debris to travel freely between components.
Innovation Solution
The integration of dielectric protrusions on the trip unit that slidably interconnect with corresponding dielectric members on the base, forming a dielectric and physical barrier that remains intact during movement, preventing debris accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the trip unit is secured to the base with limited spacing, then the device complexity is reduced and space requirements are met, but debris accumulates freely between components during trip events
Solution Approach 1:
Dielectric protrusions extend from the dielectric walls and receive dielectric members from the base, creating an intermediary barrier structure. This mediator maintains a dielectric barrier between phases while preventing debris accumulation, resolving the contradiction between simple structure and debris protection.
Solution Approach 2:
The dielectric protrusions extend vertically from the dielectric walls into the space between the trip unit and base. By utilizing the vertical dimension, the invention creates a barrier without increasing horizontal spacing, maintaining compact structure while preventing debris accumulation.
2Reliability
If dielectric walls are placed between phase enclosures, then dielectric isolation is provided, but horizontal space is consumed with limited spacing available
Solution Approach 1:
Instead of extending dielectric walls horizontally between phases, the invention extends dielectric protrusions vertically from the dielectric walls. This dimensional change provides dielectric isolation without consuming additional horizontal space, resolving the contradiction between reliability and compact dimensions.
Solution Approach 2:
The dielectric protrusions are strategically positioned at specific locations where phases are closest together. By concentrating dielectric material where it is most needed rather than providing uniform horizontal separation, the invention achieves reliable isolation with minimal space consumption.
3Object-generated harmful factors
If the trip unit can be displaced from the base during fault interruption, then arc gases can escape, but debris travels freely between components causing dielectric path breakdown
Solution Approach 1:
The dielectric protrusions with received dielectric members create an intermediary barrier that remains in place during trip events. This mediator allows arc gases to escape while blocking debris from traveling between phases, maintaining dielectric path integrity despite the necessary displacement of the trip unit.
Solution Approach 2:
The dielectric protrusions are pre-positioned to intercept debris before it can travel between phases during a trip event. By establishing this protective barrier in advance, the invention prevents dielectric path breakdown while still allowing the trip unit to displace for arc gas escape.
Data Source
Figure 1A~1B
Figure 2A
Figure 2B
AI summary
A molded case circuit breaker having a trip unit (100) with one or more integrally formed dielectric protrusions (102) that are configured to slidably interconnect with corresponding dielectric members (202) of the base (200) when the trip unit (100) is secured to the base (200). The dielectric protrusions (102) extend from dielectric walls (122) located between adjacent enclosure chambers (109) that house the current transformers (114) and are configured to remain in contact with the dielectric members (202) of the base (200) as the trip unit (100) is being moved with respect with the base (200). By remaining in contact to one another while the trip unit (100) is moved with respect to the base (200), the dielectric protrusions (102), along with the dielectric members (202), maintain a strong dielectric barrier within the exterior spaces (112) between the current transformer (114) enclosure chambers (109), thereby preventing debris from traveling between and accumulating on the trip unit (100) and the base (200).