Why Recent Changes to NEC Section 110.26 Require a Complete Reassessment of Electrical Panel Service and Circuit Capacity in Industrial Facilities


The National Electrical Code (NEC) lays out the legal requirements for safe electrical installations across the United States. As our reliance on electricity grows, the NEC must evolve to address new developments in electrical technology and changes in how we use energy. That's why the 2021 edition of the NEC includes an important update to Section 110.26 regarding electrical panel service and circuit capacity in industrial facilities.

In this article, I'll provide an in-depth look at these NEC changes and explain why they make a complete reassessment of your facility's electrical system critically important. Gaining a full understanding of the new NEC 110.26 requirements will allow you to proactively address any deficiencies and ensure your electrical infrastructure is fully compliant and positioned for current and future demands.

Overview of Key Changes to NEC Section 110.26

Section 110.26 of the National Electrical Code covers the requirements for electrical panel and service capacity in commercial and industrial buildings. The 2021 NEC update includes two major changes:

1. New Load Calculation Requirements

The updated 110.26 now requires electrical load calculations for industrial facilities to be based on actual maximum electrical load instead of estimates.

Previously, load calculations could be estimated based on square footage. However, the new language explicitly requires determining the actual realistic maximum electrical load expected on the service and feeder system.

This change recognizes that many industrial facilities now have more significant and concentrated electrical loads from large motors, drives, heating equipment, and other machinery.

2. Mandatory Push Button Tests

The updated 110.26 also introduces a new requirement for mandatory push button tests to verify the overall system capacity under maximum load.

These field evaluations must be conducted during peak load conditions to validate that the system can actually handle the true realistic maximum load.

Why These Changes Are Significant

These two key updates to NEC Section 110.26 have major implications for industrial facilities. Here are some of the key reasons the new requirements make reassessing your electrical system critically important:

Outdated Electrical Panels

Increased Electrical Demand

Improved Safety

Compliance Assurance

Performing a Complete Electrical System Reassessment

Given the significance of the NEC Section 110.26 changes, a full reassessment of your facility's electrical service capacity is likely needed. Here is an overview of the recommended best practices:

1. Load Calculation

2. Service Capacity Evaluation

3. Push Button Testing

4. Remediation and Upgrades

Leveraging Electrical Engineering Experts

Given the specialized electrical engineering knowledge required, partnering with electrical experts is highly recommended when undertaking the complete electrical system reassessment needed to meet the new Section 110.26 NEC standards.

Some key benefits of leveraging electrical engineering expertise include:

By partnering with qualified electrical engineering experts, industrial facility owners and managers can ensure their electrical systems are fully reevaluated to comply with the latest NEC 110.26 capacity requirements in a timely and cost-effective manner.


The recent changes to NEC Section 110.26 represent a major shift in requirements for electrical service and circuit capacity in industrial facilities. Mandatory load calculations and push button testing reveal any inadequacies in existing systems designed based on estimates or general rules of thumb.

To maintain safety, compliance, and readiness for current and future production needs, a complete reassessment of your facility's electrical infrastructure is now essential. By leveraging the expertise of electrical engineering professionals, this critical reassessment process can be completed efficiently and cost-effectively.

Proactive reevaluation and upgrades pave the way for optimized electrical safety and performance. Don't wait for an incident, outage, or violation to necessitate action. Partner with electrical experts now to ensure your equipment and workforce are supported by a fully modernized and NEC 110.26 compliant electrical system.