Electrical Control Panel Design & Fabrication

Electrical Control Panel Design & Fabrication is a critical discipline in industrial automation and electrical engineering. It involves designing and building custom enclosures that house electrical components used to control equipment and processes safely and efficiently.

What Is an Electrical Control Panel?

An electrical control panel is a centralized enclosure that contains electrical devices such as:

  • Circuit breakers & fuses

  • Relays & contactors

  • PLCs and I/O modules

  • Motor starters and drives (VFDs)

  • Power supplies

  • Terminal blocks

  • Wiring and labeling

Panels can be custom-designed for various applications, from simple motor starters to complex multi-panel automation systems.

Design Process

1. Requirements Definition

  • Load list: What will the panel control?

  • Input/output specifications

  • Voltage and current requirements

  • Safety and compliance standards (e.g., UL 508A, IEC, NEC)

2. Electrical Schematics

  • Developed using CAD tools (e.g., AutoCAD Electrical, EPLAN).

  • Includes:

    • Power circuits

    • Control circuits

    • I/O wiring diagrams

    • Interconnection and terminal layouts

3. Component Selection

  • Based on function, voltage, current, space, and budget.

  • Common components include:

    • PLCs (Siemens, Allen-Bradley, Schneider)

    • Relays, contactors, timers

    • VFDs or soft starters

    • Indicators, switches, HMI

4. Panel Layout Design

  • DIN rail placement

  • Cable duct routing

  • Heat management (fans, vents, cooling units)

  • Accessibility for wiring and maintenance

5. Compliance & Standards

  • Design for compliance with:

    • UL 508A (US)

    • IEC 61439 (Europe)

    • NEC / NFPA 70 (US electrical code)

    • CE Marking (EU)

    • Labeling and color coding standards

Fabrication Process

1. Material Procurement

  • Panel enclosures (sheet metal, stainless steel, polycarbonate)

  • Electrical components

  • Labeling materials

2. Enclosure Preparation

  • Cutting holes for push buttons, HMIs, cable entries

  • Mounting DIN rails and backplates

3. Component Installation

  • Mounting breakers, PLCs, relays, etc.

  • Internal wiring with proper gauge and color-coded wires

  • Labeling of terminals and wires

4. Wiring & Testing

  • Continuity and insulation testing

  • Load and short-circuit protection verification

  • Power-up testing and simulation (dry run)

5. Documentation

  • Complete set of schematics

  • Panel layout drawings

  • Bill of materials (BOM)

  • Test reports and certification documentation

Types of Control Panels

Panel TypeDescription
MCC (Motor Control Center)Centralized panel for multiple motors with starters, overloads.
PLC PanelHouses PLCs, I/O modules, relays, and communication devices.
VFD PanelIncludes variable frequency drives for motor speed control.
Remote I/O PanelExtends control to distributed locations.
Operator ConsolesIntegrated with HMI for manual operation.