Electrical Control Panel Essentials

Engineering Geek
3 min readDec 21, 2021


Any automated manufacturing process requires industrial equipment and machines in engineering plants. It requires specified functions and systematic control to meet different project goals. For instance, an electrical control panel in an engineering plant is an enclosed space that comprises various devices which use electrical power to manage and monitor numerous processes. It provides signals to direct the operation of mechanical equipment and machines. The industrial control panels (ICPs) vary in shapes and sizes as per the project requirement and need specialized individual handling.

Read on to understand product markings to ensure the right electrical control panel has been selected for your manufacturing unit for the intended function and installed following the UL classification. It is to ensure that the panel has been tested and complies with an acceptable safety standard requirement.

The three main types of product identities in UL product category NITW include;

  1. Enclosed Industrial Control Panels
  2. Open Industrial Control Panels
  3. Industrial Control Panel Enclosure

Each product identities have its unique installation application. So, it is essential to be considered by the Authority Having Jurisdiction (AHJ) when inspecting an installation.

Enclosed Industrial Control Panels

  • The enclosure consists of all the electrical components mounted to the walls or closure.
  • These panels are inspected to verify their safety functioning inside the specified marked voltage, current and short circuit current ratings.
  • Examined for shock & electrical fire hazards but not to evaluate to control electrical equipment.
  • For checking a UL Listed enclosed industrial control panel, the Authority Having Jurisdiction (AHJ) is only essential to validate that the machinery has not been destructed, its marked ratings are suitable for the load & projected working, the connections are suitably concluded, and there have not been any field alterations to the wiring schematic.

Open Industrial Control Panels

  • It consists of internal wiring, terminals, and several components mounted to the subpanel that does not feature a complete enclosure.
  • The enclosure in this type of panel is only expected to be supplied as a part of the installation.
  • Other factors that need to be considered when approving the installation of an open industrial control panel include,
  • Assess and understand the builder’s installation guidelines, which may define a specific application requirement.
  • Verify panel’s appropriateness for installation and utilize in conformity with the terms of the NEC
  • Validate resilience and mechanical strength of the chosen enclosure
  • The required wire-bending and conductor termination space must not be intruded
  • Safeguards various places to prevent contact with workers that may be near the open control panel.

Industrial Control Panel Enclosures

  • Investigated for compliance with the construction-based needs outlined within UL 508A, the UL Standard for Safety in Industrial Control Panels.
  • Re-evaluated by the authority having jurisdiction (AHJ) after installing the electrical components.

Markings Requisite in National Electrical Code (NEC) Section 409.110 and More

  • Producer’s name, brand name, or other informative markings by which the company responsible for the product can be classified.
  • The number of phases, Supply voltage, frequency, and full-load current for each incoming supply circuit.
  • Short-circuit current rating of the ICPs as follows,
  • A listed and marked assembly
  • Established utilizing an authorized method
  • The ICP planned as service equipment shall be marked accordingly to label it for use as a service component.
  • Electrical wiring diagram or the ID number of a separate electrical wiring diagram or a designation referenced in a separate wiring diagram
  • Mark the industrial control panel with enclosure type.

Wire your Facility Effectively!

Industrial control panels perform a vital role in a wide range of industrial processes and applications. If you’re looking for ICPs tailored to your manufacturing plant requirement, consider partnering with an experienced electrical design company.