Cable Assemblies & Box Build Services in Portsmouth

Professional wiring looms, cable harnesses and full system integration for UK manufacturers.

We provide high-quality cable assemblies, wiring looms and complete box build solutions for businesses across the UK. With over 35 years of experience, our skilled technicians deliver clean, accurate and dependable wiring systems designed to support prototypes, production builds and fully integrated electronic products.

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Why Choose Phase One Electronics for Cable Assemblies & Box Build?

We understand the importance of clean, accurate wiring and dependable system integration. With more than 35 years of manufacturing experience, our cable assemblies and box build services are designed to deliver consistent, high-quality results for industries where reliability cannot be compromised. Whether you need a simple loom or a fully integrated enclosure, our technicians work with precision and attention to detail at every stage.

35+ years of wiring and system integration experience

Proven track record across demanding UK industries.

Complete UK-based production

Everything built in our Portsmouth facility — zero outsourcing.

Built to your exact specifications

We follow your drawings, BOM and requirements precisely.

Flexible batch sizes

One-offs, prototypes, small runs or ongoing scheduled supply.

Industry versatility:

Marine, defence, industrial, automotive, medical and more.

Skilled wiring technicians

Trained in consistent, accurate crimping, soldering and termination.

Our Cable Assemblies & Loom Manufacturing Process

Our cable assembly and wiring loom processes have been refined over decades to ensure accuracy, repeatability and reliability. Whether you require simple labelled leads, multi-branch wiring looms, or fully documented harnesses for regulated industries, our technicians follow structured procedures designed to deliver consistent results.

Documentation review

We assess wiring diagrams, schedules, pinouts, connector types and technical requirements.

Precision cutting & stripping

Automated tools ensure consistent cable lengths and preparation.

Professional termination

Crimping, soldering, IDC and specialised connector assembly.

Loom building & routing

Boards, templates, sleeving, braiding and strain relief for clean, organised layouts.

Labelling & identification

Heatshrink markers, tags, numbering and full documentation.

Electrical testing

Continuity, polarity, pinout, isolation and connector integrity checks.

Our Box Build & System Integration Process

Our box build services bring together PCBs, wiring, power systems and mechanical hardware into complete, ready-to-use units. From simple control boxes to fully integrated electronic systems, we follow a structured process that ensures every enclosure is assembled cleanly, wired correctly and tested thoroughly before it leaves our facility.

Mechanical assembly & enclosure preparation

We work with plastic, metal and IP-rated enclosures, fitting standoffs, mounting hardware, gaskets and grounding points.

PCB integration

Boards are installed securely with the correct spacers and fixings, protecting against vibration, shock and mechanical stress.

Internal system wiring

All internal looms are routed carefully to switches, connectors, displays, sensors, relays and power supplies, maintaining clear access and airflow.

Power system installation

AC/DC supplies, converters, fuses, earth bonding and protection devices are installed in line with your requirements and safety standards.

Final assembly and fit checking

We ensure covers, doors and panels close correctly, with no cable snagging or strain and all connectors accessible.

Functional testing & verification

Power-up checks, signal tests and customer-defined routines confirm that the finished assembly operates exactly as intended.

Industries We Support with Cable Assemblies & Box Build

Our cable assemblies and system builds are trusted by businesses across a wide range of industries.
These sectors rely on strong, clean and reliable wiring systems that support long-term operation in demanding environments.

Marine &
Offshore

Electronics that must withstand corrosion, moisture, vibration and long-term exposure to harsh environments.

Defence &
Military

Reliable, secure, safety-critical circuits designed for mission-ready performance and strict quality standards.

Automotive &
Electric Vehicles

Electronics exposed to constant vibration, heat cycling and extended operating lifetimes.

Medical &
Healthcare Equipment

Safety-critical systems that require complete stability, cleanliness and predictable long-term operation.

Telecommunications &
Surveillance

Electronics that must deliver signal integrity, uptime and reliable data processing in varied environments.

Industrial Automation &
Robotics

Precision control systems used in 24/7 environments where failure is unacceptable.

Rail, Transport &
Infrastructure

Durable electronics designed for heavy-duty, mission-critical applications in transport and public infrastructure.

Audio & Music Industry

Group of people at a sound mixer station

Electronics used in live sound, studio recording and broadcast environments, requiring ultra-low noise performance, stable signal processing and long-term reliability under continuous operation.

Request a Cable Assembly or Box Build Quote

To provide an accurate and reliable quotation for cable assemblies or full box-build projects, please share the key details of your requirements. This helps us assess complexity, materials, labour and any specialist processes needed, ensuring we respond quickly with clear pricing, expert guidance and realistic lead-time expectations.

Wiring Diagrams or Schematics

Supplying clear diagrams allows us to understand routing, termination points, wire gauges and overall design intent.

Cable Schedules

Cable schedules allow us to assess lengths, quantities, labels and any custom markings or identification needed.

Bill of Materials (BOM)

A complete BOM helps us confirm part availability, material compatibility and any specialised sourcing or alternatives required.

Quantities Required

Whether you need a single prototype, a short run or ongoing production batches, we tailor pricing to match your volume and manufacturing plan.

Testing Requirements

Let us know if you require continuity testing, high-pot testing, functional testing or customer-specific verification procedures.

Lead-Time Expectations

Share your project deadlines or any urgent production needs so we can plan capacity and provide accurate delivery times.

Connector Types & Specifications

Provide details of all connector types, manufacturers and part numbers so we can verify compatibility and confirm tooling or crimping requirements.

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