Stages of the Electrical Commissioning Process
But what goes into electrical commissioning, how is it handled, and how can the commissioning industry do it better? This guide on electrical testing will explain.
Most commissioning processes (also known as Cx) follow a relatively systemized procedure. That's true of electrical commissioning, as well, as it is simply a part of the larger commissioning process and test, not a function on its own. However, the following sections will explain the electrical commissioning component of a Cx test.
Preliminary Assessment and Planning
The first step in performing commissioning of an electrical installation is the initial assessment of the system or components and the planning of the Cx process. The commissioning agent (CxA) will investigate and review the equipment and system schematics and instrumentation diagrams (PID). The CxA uses these documents to ensure they understand how the current is running in the system and how it integrates with other systems and equipment (power supply). This also allows them to determine what needs to be tested and verified to be working.
For example, these documents will highlight equipment and components such as fuses and their sizes, breakers, cables, parallel usage, and more. With these documents to review, the CxA knows what to look for to ensure everything is installed to spec. Also, if there are any high voltage (HV) systems, they're able to design the entire process to ensure safety.
The CxA also assembles a commissioning team. The Cx team consists of engineers, contractors, subs, and building maintenance personnel. These members will be responsible for particular tasks during the commissioning process.
Circuit and System Testing
After assembling the team and a plan, the next step is circuit and system testing. The goal is to verify that the system is working properly, safely, and according to the owner's project requirements (OPR).
There are a few stages to circuit and system testing. These include commissioning activities during the pre-energization, energization, and post-energization phases.
- Pre-energization involves ensuring that circuits, switches, transfer switches, or components are mounted according to the project specs and in the off position.
- Energization involves taking readings, testing circuits, or ensuring that individual components and sensors are operating correctly. The sequence for this testing process will follow the specific functional description, where the logical sequence is described. Most often tools like meggers will be used for automated testing of the V, A, and O on the system. Meggers can auto-generate the current and force the RFD to cut off or highlight long cables where the current drops too much to activate the RFD.
- Post-energization includes ensuring that all of the control and transfer switches are in the correct positions and turn off when the system is de-energized. This test also includes verifying that all lock-out equipment is functional.
Verification of Safety Protocols
One of the most important aspects of electrical commissioning is the verification of safety protocols. This part of electrical commissioning takes the testing beyond the operation of the electrical system and ensures that the safety protocols in place work from a practical standpoint.
The thermography of switchboards is a core part of the verification of the safety protocols. The thermography is often also a part of the load test during the circuit and system testing, but will also be performed as a standalone activity. When performed as a standalone activity:
- Ensure the power is on all switchboards.
- Ensure that equipment is attached to the switchboards using the designed and nominal power (A).
- After 60 minutes, all potential doors on switchboards are opened.
- A full walkthrough with the thermography camera is performed, where all switchboards are checked. This ensures that any loose wire or termination can be found and fixed before the final handover.
Documentation and Handover
This entire process has to be documented by the Cx team. This allows the team to put together a plan for fixing deficiencies and provides a helpful baseline for efficient operation. But with so many tasks involved, it's best to use commissioning software like CxPlanner, as it can help keep all of the tasks organized and make assigning them to the individual team members straightforward.
The documentation can normally be divided into:
- Schematics and PID diagrams showing the electrical system structure
- Functional descriptions including how it should work
- Automated test reports using tools like meggers, etc.
- Thermographical documentation for the switchboards
All of this data is collected and reviewed. Once all of the systems, switches, fuses, and other electrical components are verified to be in working order, the Cx process is prepared for handover. This phase is when CxA ensures that the electrical system meets the owner's project requirements and operates as it should.
Roles and Responsibilities in Electrical Commissioning
With so many tasks associated with electrical commissioning, it's important to break the project into roles. Each role will have its own tasks to perform, making a large-scale commissioning project easier to tackle.
The Electrical Commissioning Agent
The commissioning agent focusing on the electrical testing will often be an individual who has previously worked within the electrical field. That could be within low voltage, high voltage, BMS systems, etc.
The person's competences must be chosen based on the electrical systems included in the specific commissioning job. Some of the needed activities for this person is:
- Developing specific electrical requirements for the building (OPR). Whether it is the number of power outlets to the redundancy of power to the cooling system
- Performing design review of the architectural drawings for the design of the electrical installations to the detailed schematics showing cable connections and terminations.
There are more responsibilities, as well. For example, the CxA is responsible for coordinating communication between all of the members of the Cx team. CxPlanner can streamline this, providing a platform for all members of the Cx team to communicate about tasks, deficiencies, schedules, and more.
Collaboration with Electrical Engineers and Technicians
Since the CxA is responsible for developing and maintaining the OPR, they also develop the Basis of Design (BoD) with the designers. The BoD will ensure that electrical items in the OPR, such as requirements for breakers or the over-dimension of cable trays, are replied to directly in the BoD.
During the detailed design phase, the CxA will start to develop test programs and test plans for the electrical installations. It's wise to involve the designer in this development since their knowledge of the system can highlight potential errors and critical points in the test.
Technology's Role in Electrical Commissioning
With advancements in modern electrical systems, it only makes sense to embrace technology in the tools we use to commission them. The benefits of using CxPlanner commissioning software are many:
- Real-time tracking allows Cx teams, owners, and CxAs to determine exactly where the commissioning process stands, receive updates automatically, communicate about deficiencies, and keep all of the team members on track.
- Clear plans and testing schematics to make understanding, carrying out, and recording the different tasks on an electrical commissioning projects simple
- Simplified document management to store drawings, reports, and other Cx documents in one place.
- Digitally-based recording and reports can replace Excel spreadsheets and handwritten recording
- The flexibility to handle any type of commissioning project, such as electrical, building, mechanical, and more
- Faster and easier handover package preparation including important documents and reports to ensure the project owner's needs are met during handover without sacrificing thoroughness or quality.