The 2023 edition of the National Electrical Code has incorporated “commissioning” in various rules that until now only required a system witness test. Adding commissioning creates additional steps and processes to attain compliance with those revised rules, which include sections 700.3, 701.3, 706.7, 708.8 and a new definition in Article 100. Let’s look at what commissioning building electrical systems entails to help clarify and raise awareness of the intended (or unintended) additional mandatory requirements.

Commissioning’s intent is to ensure all electrical equipment, components, subsystems and systems are installed according to the contract documents, construction drawings and specifications, manufacturer instructions and industry-accepted standards. It’s also to check that the installed equipment, components and systems are complete and receive adequate operational checkout and detailed testing, calibration and adjustment by the installing contractor.

Commissioning electrical systems

Commissioning building electrical systems is a systematic process to ensure all procedures, checks and testing are rigorously executed and documented, and that all systems perform in accordance with the design intent and the owner’s requirements. This is achieved by verifying that the performance meets or exceeds the designer’s intent in the project drawings and specifications.

The commissioning process integrates the traditionally separate functions of equipment startup, control system calibration, testing and balancing (including electrical load balancing as the NEC requires), functional performance testing, system documentation and training. It may also include deferred functional and seasonal tests the owner approved and accepted.

The commissioning process does not reduce the contractor’s responsibility to provide a complete, finished and fully functioning electrical system installation. Commissioning typically is performed by an independent third party, the commissioning authority. The authority having jurisdiction (AHJ) is typically not a commissioning authority. The commissioning authority cannot provide direction to contractors. Any issues that arise affecting schedules, costs or contractual obligations must be addressed by the owner for resolution. 

The commissioning authority typically develops and coordinates a plan and supplies it as part of the contract bid documents. The plan provides guidance for the execution of commissioning activities and a broad outline of the entire process. It usually details the commissioning activities during design and construction, occupancy and operational commissioning activities and the roles and responsibilities of all commissioning team members, by name, firm and trade specialty, for performance of each commissioning task. 

Commissioning team members include the commissioning authority, owner, general contractor, design engineers or architects and mechanical and electrical subcontractors. The dynamic commissioning plan is updated throughout the project’s design, construction and warranty phases.

Commissioning building electrical systems requires cooperation and coordination among all applicable trades. The contract documents and commissioning plan usually delineate the roles and responsibilities of the commissioning authority, the electrical design engineer, general contractor and mechanical and electrical subcontractors.

Additionally, acceptance or witness testing is usually completed by one or more independent, certified third-party testing agencies. Subcontractors typically coordinate with each testing agency so the commissioning authority, owner, architect, engineer or any interested team members can simultaneously witness tests to ensure contractual and Code requirements are met. Acceptance and witness testing are typically a small portion of the overall commissioning process and are a requirement of the AHJ prior to issuing approvals.

Usually, contractors must participate in resolving system deficiencies and noncompliance in materials, installation or setup related to their trade identified during the commissioning process in accordance with contract documents and the owner’s project requirements.

Contractors typically provide the documentation required for commissioning, such as shop drawings and product submittal data, detailed startup procedures (including manufacturer’s procedures), prefunctional checklists, functional performance test procedures, control drawings, details of any owner-contracted tests, equipment startup certification forms, manufacturer field or factory performance tests and startup test documentation.

Including commissioning in existing NEC rules introduces significant additional requirements beyond just witnessing performance tests, as the previous rules called for. AHJs will have to determine how to enforce these additional rules on projects. This potentially affects multiple entities, including electrical contractors.

Note: ANSI standards that provide details about commissioning processes for building electrical systems include ANSI/NETA ECS, Standard for Electrical Commissioning Specifications for Electrical Power Equipment and Systems, and NECA 90, Standard for Commissioning Building Electrical Systems.

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