Commissioning

Commissioning of electrical systems

Commissioning of electrical systems has become an integral and well-established part of the building design and construction process. However, as cities and states increasingly pass more stringent energy legislation while new technologies continue to present countless possibilities, building systems will get smarter and more interconnected—and the role commissioning plays in the built environment will continue to expand.
By Vahik Davoudi, PE, LEED AP; Ander Sahonero, PE; Gaurav Thatte, EIT; and Rahul Mittal, EIT; Arup, Los Angeles March 25, 2019

Learning objectives

  • Gain an understanding of the present-day commissioning process and how it applies to electrical systems.
  • Become familiar with the standards that drive the testing and commissioning of electrical systems, and how these standards are incorporated into the design of a building or facility.
  • Acquire insight into the direction of the industry and how innovation and new technologies are leading to highly integrated building systems, driving the need for more detailed and involved commissioning standards and practices.

Commissioning (Cx) of electrical systems is the process of testing and accepting the installation of electrical equipment and verifying the overall performance of the system. While testing of components according to industry standards is the first step to ensuring code compliance and proper installation of electrical equipment, the goal of Cx is to verify that all the electrical systems, in conjunction with the rest of the building systems, meet the facility’s objectives, operational requirements, and performance goals.

Cx of electrical systems can be implemented at any stage of a building’s lifecycle, but it is most effective when initiated during the early concept and planning stages of a project. At this stage, the owner—sometimes assisted by a third-party representative—begins to assemble the Cx team, which comprises the owner’s representative(s), commissioning authority (CxA) or commissioning professional (CxP), design and construction teams, operations and maintenance (O&M) personnel, and if possible, a group of users representing the needs and interests of the intended occupants.

Figure 1: The lighting installation in this hospital’s main entrance enhances the staff, visitor, and patient experience. The luminaires and lighting controls were commissioned to coordinate with holiday colors and interact with visitors. Courtesy: Arup

The first step for the Cx team, with input from all these stakeholders, is to define the scope and level of Cx required based on the proposed building type, systems, and operational intent of the facility—and incorporate these findings into the owner’s project requirements (OPR). The design team then integrates these Cx requirements into the design documents, which outline the desired system’s documentation, equipment installation/energization procedures, start-up and operation of control systems, performance testing, and personnel training.

The Cx team evaluates which electrical systems require Cx to be performed, including but not limited to the following:

  • Distribution system: unit substations, switchgear, switchboards, motor controllers, panelboards, transformers, wire, and cables.
  • Emergency system: generators, generator controls, paralleling gear, transfer switches.
  • Uninterruptible power supply (UPS) systems.
  • Transient voltage surge suppressors.
  • Overcurrent protection devices and relay-protection systems.
  • Lighting and lighting control systems.
  • Power monitoring and supervisory control system.
  • Grounding and bonding system.
  • Renewable energy systems, such as photovoltaic.
  • Microgrid.
  • Internet of things systems.

The successful Cx of electrical systems verifies that these perform as intended per the OPR and achieve the following objectives after the construction and handover of the project, according to the design drawings and specifications:

  • The electrical equipment and systems are installed as specified in the contract documents and per the manufacturer’s recommendations.
  • The electrical equipment and systems are integrated and functioning, and their performance is documented.
  • The electrical systems operate properly as intended for any given scenario.
  • O&M manuals and documentation are relevant and complete.
  • The facility’s staff, also known as O&M personnel, have completed the requisite training to operate and maintain the electrical systems.

Planning for and integrating the Cx of electrical systems in design documents offers many benefits to the project. It provides the opportunity to address critical issues early on and to reconcile any gaps or overlaps that could have major cost and schedule impacts. It also often results in reduced O&M costs over a facility’s lifespan. The key benefits of electrical design with a Cx mindset are improved reliability and uptime, increased energy performance and sustainability, reduced unscheduled maintenance, and longer lifecycle of equipment.

Figure 2: Proper installation and commissioning of switchgear will ensure a high degree of operational reliability. Results of electrical tests follow acceptance-testing specifications, such as ANSI/NETA ATS, for electrical power equipment and systems. Courtesy: Arup

Application through design

Many standards and guidelines make up the modern Cx process. ASHRAE Standard 202-2018: Commissioning Process for Buildings and Systems establishes the mandatory requirements of Cx. It explains the Cx process and provides a basic framework to develop design documents, procedures, reports, and specifications.

Code-required Cx is an important aspect of electrical system design, and different buildings follow different codes and standards based on their occupancy or building type. For example, health care projects rely mostly on NFPA 99: Health Care Facilities Code and NFPA 110: Standard for Emergency and Standby Power Systems, commercial buildings are guided by the InterNational Electrical Testing Association (NETA), and mission critical facilities tend to follow the Building Commissioning Association (BCxA).

Most of these standards are developed using NETA and ASHRAE 202-2018. However, health care facilities use the Health Facility Commissioning (HFCx) handbook published by American Society for Healthcare Engineering (ASHE) of the American Hospital Association as their guide for new construction projects and existing facilities.

The NFPA Standards Council recognized the need for a more technical guide on the Cx of fire protection and life safety systems, so it developed a Cx standard. Later, the committee determined that Cx and integrated fire protection/life safety system testing are two separate tasks that should be treated separately from an NFPA standards point of view. This led to the creation of NFPA 3: Standard for Commissioning of Fire Protection and Life Safety Systems, which focuses on Cx, and NFPA 4: Standard for Integrated Fire Protection and Life Safety System Testing, which addresses integrated system testing on fire protection and life safety systems.

NFPA 3 defines the minimum requirements for the Cx process to verify that fire protection and life safety systems perform in conformity with the OPR, design documents, and applicable governing codes, regulations, and standards. The services, products, and deliverables required by this standard must provide the necessary documentation for the owner to verify the continued performance and operation of these systems.

NFPA 4 defines the minimum requirements for integrated testing and documentation before building occupancy. The standard applies to active fire protection and life safety equipment and systems. The main objectives of these tests are to verify and document that all integrated system testing for fire protection and life safety systems have been completed, inspected, and approved, and all outstanding fire protection and life safety issues have been addressed to afford a reasonable degree of safety to the building occupants from fire and similar emergencies.

NETA standards

Because NETA Acceptance Testing Specifications (ATS) covers the acceptance-testing specifications that identify the suitability of the equipment based on initial energization and final acceptance, there was a need for specifications that define the procedure for Cx and the proper documenting procedure that goes with it. With this approach, the American National Standards Institute (ANSI)/NETA Electrical Commissioning Specifications (ECS) was developed (see Table 1).

ANSI/NETA ECS describes the process of documenting and placing in service newly installed or retrofitted electrical equipment and systems. The specifications are intended to ensure safety, reliability, and optimal operation in conjunction with applicable standards, design specifications, and manufacturers’ tolerances. These Cx specifications are tailored explicitly for electrical power equipment and systems; they do not address all safety issues but intend to provide a systematic approach toward Cx. Individual components must be subject to necessary field and factory tests for essential validation. ANSI/NETA ECS must be used along with ANSI/NETA ATS to ensure a complete and thorough Cx approach.

These Cx standards and guidelines are incorporated into the design team’s specifications and listed under MasterFormat Division 1, Section 01900, General Commissioning Requirements, which forms the basis of the construction-phase Cx process and procedures. The CxA must define all applicable Cx procedures to suit field conditions and actual manufacturers’ equipment, incorporate test data and procedure results, and provide detailed scheduling for all Cx tasks.

Section 01900 references Division 26, Section 260800, Commissioning of Electrical Systems. This section defines the labor, materials, and equipment necessary to complete the start-up and Cx of electrical systems. This section references and establishes compliance with the latest edition of the following standards:

Cx of electrical systems is often connected with Division 25, Section 250800, Commissioning of Integrated Automation, primarily because a large portion of the scope of measurement and verification systems in this section falls between trades.

 LEED Enhanced Commissioning

The successful Cx of electrical systems is critical to delivering high-performing buildings. Performing Cx tailored to the intended operation of a facility can lead to significant reductions in operating costs of energy-related systems and equipment in buildings. Recognizing the benefits that Cx would provide in green buildings, the U.S. Green Building Council added Cx as a component in the LEED certification process known as Enhanced Commissioning. This standard supports the design, construction, and operation of a project that meets the OPR for energy, water, environmental quality, and durability.

Early involvement of a Cx team helps prevent long-term maintenance issues and wasted energy by verifying that the design meets the OPR and functions as intended. Enhanced Commissioning also can help the owner achieve six LEED points. The LEED Enhanced Commissioning credit also provides the benefit of involving the CxA during the design phase to provide design review as well as a systems manual and training verification during construction.

The CxA must have the Cx process well-documented, and prior experience of at least two building projects with support from early design to occupancy is required. The Cx team must have a designated safety representative onsite to oversee operations concerning safety and OSHA requirements.

Building codes apply to all buildings and are pushing Cx to a much broader market. However, LEED focuses on Cx solely from an energy standpoint and excludes important electrical systems from its scope. Therefore, it is important to consider the Cx of electrical systems outside of the LEED scope when pursuing LEED accreditation. The more complex electrical systems tend to be part of buildings that do not traditionally seek LEED accreditation. Nonetheless, LEED has helped promote Cx and early involvement in the design process.

The future of Cx for electrical systems

Most equipment manufacturers are striving for innovation within their markets, but the industry is slow to adopt new technologies. Defining and settling on new standards that will facilitate the integration of new technologies and prepare the industry for future innovation has become a top priority. Modern innovation and integrated design have blurred the division of roles and responsibilities among architects, engineers, and contractors, often leading to issues and disputes during construction.

When developing the Cx requirements in the OPR, the Cx team should give special consideration to implementing monitoring-based commissioning (MBCx). MBCx pairs the most advanced Cx techniques with the latest electrical equipment and systems technology to automatically gather and analyze building systems data. As the load profile of a facility changes over time, monitoring-based integration decreases maintenance and increases operational cost savings by assisting with energy monitoring (e.g., notifying the facility engineer when to change a trigeneration plant’s filters), power quality, and sensory feedback (e.g., oil-sample sensors in substation transformers can warn of problems before they occur and prevent faults that are costly to repair and result in a loss of service).

In the end, the owner and Cx team can be confident that the electrical equipment and systems function according to the intent as initially defined in the OPR and design documents. Over the life of the building, electrical equipment and systems will be optimized to save energy and reduce costs. Other benefits can include a safe facility, well-trained staff, and better electrical equipment and systems documentation. The positive outcomes of incorporating Cx into the design and construction of electrical equipment and systems far outweigh the cost and difficulty of implementing it.

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Vahik Davoudi, PE, LEED AP; Ander Sahonero, PE; Gaurav Thatte, EIT; and Rahul Mittal, EIT; Arup, Los Angeles
Author Bio: Vahik Davoudi is one of the long-term leaders in Arup’s Los Angeles office. He has many years of experience in the design of sustainable and large-scale projects. Ander Sahonero is a senior electrical engineer at Arup, focused on the multidisciplinary design of large and technically complex projects. Gaurav Thatte is an electrical engineer with Arup, designing electrical systems and specializing in health care projects. Rahul Mittal is an electrical engineer for Arup, designing electrical power systems primarily for commercial projects. He specializes in computer-aided analysis of power systems and protection