Defense and aerospace applications expose high-voltage cable assemblies and connectors to shock, vibration, temperature extremes, corrosives, dirt, and rough handling. Reliable performance starts with a design suited to the operating environment with an appropriate margins.
For engineering teams, the question is whether the complete assembly will maintain electrical and mechanical performance throughout its intended life.
High-voltage failures can originate where geometry or materials change , including a conductor termination, shield cutback or termination, or the mating interface. Sharp points and trapped air can create conditions for localized electrical discharge which can lead to premature failures.
Selecting the right insulation materials is the first step in developing a reliable connection, the second is craftsmanship. Without properly assembled products, the best materials will not prevent failure.
Corona is a form of partial discharge that occurs when the local electrical field ionizes the surrounding gas. In a high voltage assembly, sharp conductive features, such as a stray strand of shielding braid can concentrate the electric field and create a discharge site.
The erosion of insulation by corona is cumulative, and can cause a failure without warning. A brief hi-pot test establishes whether the insulation withstands a specified voltage for a defined time. It does not establish that the assembly is free of partial discharge.
Corona testing evaluates a different aspect of performance. A corona test procedure identifies the applied voltage, waveform, test conditions, measurement sensitivity, and acceptance limit.
The performance of the product depends on the complete construction. Cable insulation, connector dielectrics, overmold materials, and their interfaces must function together under the expected electrical, thermal, and environmental conditions.
Material selection needs to account for more than just dielectric strength. Corona resistance, flexibility, temperature, chemical compatibility, and resistance to mechanical damage can all influence suitability.
A high-voltage connector must maintain its intended geometry and contact engagement after installation, handling, and environmental exposure.
Application review should address:
A reliable design must be supported by a repeatable manufacturing process. Production must consistently reproduce the materials, geometry, and workmanship established during development and qualification.
Customer requirements may specify workmanship standards such as IPC/WHMA-A-620 for cable and wire harness assemblies or IPC J-STD-001 for soldered assemblies. All applicable standards, revisions, and acceptance requirements should be defined in the program documentation.
In addition to workmanship standards, suppliers must control released drawings, material specs, assembly procedures, test procedures, engineering changes, and ensure the workforce is trained.
Caton’s engineering process includes configuration control, review of proposed changes, manufacturing feasibility assessment, and assembler training and certification throughout the program lifecycle.
Qualification testing and production acceptance testing serve different purposes. Qualification evaluates a design against defined requirements. Production acceptance checks delivered hardware against its specified acceptance criteria.
An application-specific plan may include dielectric withstand, insulation resistance, partial discharge, temperature cycling, reduced-pressure testing, vibration, or mechanical testing. The required combination depends on the design and service environment.
For environmental qualification, a reference to MIL-STD-810 needs supporting detail. The standard describes an environmental tailoring process; the relevant methods, conditions, durations, and acceptance criteria must be established for the application.
Testing should answer a concrete question: does this assembly meet its electrical and mechanical requirements under the conditions it will encounter?
Before selecting a high-voltage connector, share the operating voltage and waveform, current, environmental conditions, mechanical constraints, expected mating cycles, and required qualification evidence with the manufacturer.
Caton designs custom high-voltage connectors and cable assemblies, with engineering support spanning requirements evaluation, insulation and interface design, prototyping, testing, and production.
Developing a high-voltage interconnect for defense electronics? Contact Caton with your application requirements to discuss connector and cable assembly fit.