Technical guide
Detailed information about HV Electrical Installations Engineering, Installation, Testing and Commissioning
HV electrical facilities design installation testing commissioning — this guide covers the scope, application method, quality criteria and reporting process for your needs.
Integrated HV engineering in 1–380 kV facilities
The success of the HV electrical facilities design, installation, testing, and commissioning service depends on the disciplines being managed with common design criteria rather than in isolation from one another. The single-line diagram, short-circuit calculation, primary equipment selection, protection philosophy, DC system, and SCADA architecture must all support the same operating scenario. Plan-Test addresses the 1–380 kV engineering scope throughout the project life cycle for substations, distribution centers, power generation facilities, and the connection systems of industrial plants.
In the first stage, the connection conditions, the facility's load or generation profile, the short-circuit level, the reliability target, and the possibility of expansion are determined. In existing facilities, a site survey and document verification are carried out; in new facilities, the design inputs and responsibility boundaries are recorded. In this way, primary and secondary design work is tied to the objectives of safe operation, selectivity, ease of maintenance, and acceptable performance rather than merely producing drawings.
Primary-secondary designs and engineering calculations
In the high voltage design package, the single-line diagram, general layout, sections, cable routes, grounding, lightning protection, lighting, auxiliary AC-DC systems, and secondary wiring diagrams are developed together. The load flow and voltage drop calculation verifies cable and busbar selection; the short-circuit calculation verifies equipment withstand; and the grounding calculation verifies touch and step voltage safety. The correct transfer of calculation results into drawings, specifications, and material lists is checked specifically.
In protection and control design, instrument transformer ratios and classes, relay functions, the trip matrix, interlocks, signals, and communication points are defined. The interfaces between panels from different suppliers are reviewed at terminal level. TEİAŞ, TEDAŞ, the relevant distribution company, IEC, and manufacturer criteria are applied according to the project type. A document management process is established so that revisions reach the site in a controlled manner and obsolete drawings are taken out of use.
HV facility installation and site quality control
During the HV facility installation stage, mechanical and electrical details matter as much as correct equipment positioning. Power transformer accessories, circuit breaker and disconnector mechanisms, busbar connections, cable terminations, grounding conductors, panels, and auxiliary systems are checked against the manufacturer's instructions and the approved project. Torque values, phase sequence, clearances, labels, cable screen connections, and terminal tightness are recorded. Works that will remain concealed are verified before being closed up.
Installation quality control reduces rework that could arise during commissioning. For each piece of equipment, the hold points in the inspection and test plan are defined; nonconformities are classified and assigned to the responsible party. A correction is required to be closed not merely by a declaration that it was done, but with a photograph, measurement, or re-test. Because the Plan-Test site team monitors the primary and secondary installation interfaces together, a mismatch between current transformer polarity and the relay circuit, for example, can be detected before energization.
Substation test program
The substation test program combines equipment-based checks with system function tests. The required primary tests are planned for power and instrument transformers, circuit breakers, disconnectors, cables, busbars, the grounding system, the battery-charger group, and panels. Then protection relays, metering circuits, interlocks, alarm-signal points, meters, remote control, and the trip chain are verified with secondary tests. The test sequence is arranged according to the installation completion status and the energization plan.
The calibrations of the test devices to be used, the test connections, acceptance limits, and recording format are determined before the work begins. If deviations appear in the results, connection errors, equipment condition, environmental conditions, and measurement uncertainty are examined systematically. Instead of a mere 'pass/fail' statement, the measured value, the reference criterion, and a technical interpretation are written into the report. This approach helps the first energization to be carried out in a controlled manner and provides reliable baseline data for future maintenance work.
Commissioning, energization, and acceptance
The substation commissioning plan includes the operational boundaries, switching sequence, responsible persons, communication method, and fallback scenario. Before energization, the open work list is reviewed, critical items are closed, temporary connections are removed, and it is verified that the protection settings are approved. The DC system, trip circuits, interlocks, and emergency functions are treated as prerequisites for energization. Coordination with the relevant operations center is recorded.
After energization, voltages, phase sequence, load currents, transformer and busbar behavior, alarm records, and communication points are monitored. For the HV acceptance procedures, test reports, as-built projects, equipment documents, setting files, and operating instructions are prepared. Plan-Test aims for deficiencies to be closed according to their technical importance and for the acceptance file to be consistent with the site reality. In this way, the controlled handover of the facility from the project team to the operations team is ensured.
As-built documentation and handover to operations
The safe operation of a commissioned facility is directly related to quick access to up-to-date documentation. Site revisions are applied to the single-line diagram, cable list, terminal plan, relay settings, SCADA list, and layout sheets. Test sheets are matched with equipment codes; the software and setting files used are archived with version information. Open warranty items and follow-up measurements are listed separately.
During handover to operations, the equipment operating principle, normal and emergency switching, maintenance intervals, and safety limits are conveyed to the relevant personnel. A well-prepared as-built file is not merely an acceptance document; it is the fundamental technical resource for fault finding, maintenance planning, and future expansions. Plan-Test's high voltage design and commissioning approach regards the energization of the facility not as the last step but as the beginning of reliable operation.
Plan-Test’s quality, safety and reporting approach
Plan-Test does not treat the service scope merely as a list of operations to be performed on site. The facility's operating objective, outage availability, existing documentation, equipment history, and risk level are evaluated together. Before the work begins, responsibilities, access conditions, de-energization and re-energization steps, and reporting expectations are clarified. This is intended to keep teams working from the same plan, prevent critical checks from being skipped, and make efficient use of site time. Because each project is planned according to its own technical conditions, the method, devices, team size, and delivery documents to be used are clearly defined at the proposal stage.
Our quality approach is based on explaining what the result means rather than presenting the measurement result on its own. The calibration status of the test devices used, the ambient and load conditions, the connection arrangement, the applied standard, manufacturer criteria, and any previous measurements are linked together in the report. Nonconformities are classified by severity; findings requiring immediate intervention, issues that can be addressed in planned maintenance, and trends that should be monitored are separated from one another. This method helps the investor, the operations manager, and the site team turn the same technical data into a decision-ready output.
Occupational health and safety is an inseparable part of all services. The site-specific risk assessment, personal protective equipment, lockout-tagout steps, absence-of-voltage verification, and grounding and bonding rules are reviewed before the field work begins. Inspections carried out in an energized facility are based on safe approach distances and operating instructions. Plan-Test's goal is to combine technical verification with a safe working discipline in the same process and deliver sustainable, traceable, and auditable engineering services in 1–380 kV energy facilities.
At the proposal and mobilization stage, clearly defining the scope matters for both the employer and the site team. Plan-Test determines the required activities by reviewing the existing drawings, the equipment list, the facility's operating regime, previous reports, and the employer's expectations. Out-of-scope items, necessary preparatory work, the need for de-energization, operational accompaniment, and third-party responsibilities are put in writing. When a new condition arises on site, no uncontrolled scope change is made before its impact is evaluated in terms of technical, schedule, and resource aspects. In this way, all parties understand throughout the project which activity is being performed and why, which data is expected, and against which criterion acceptance will be made. This clarity reduces repeat visits and misplaced expectations while making the delivered engineering service comparable.
The quality of field work depends on the team's experience and cross-disciplinary communication as much as on the equipment used. Plan-Test assigns tasks according to the test or maintenance steps and opens points requiring primary, secondary, project, and operational knowledge to joint evaluation. Measurement devices are used with accessories suited to the application, their calibration validity is checked, and raw data is stored securely. When a critical result is observed, the connection, device settings, environmental conditions, and the equipment's operating history are reviewed again instead of jumping to a hasty interpretation. Verification with a different method is proposed when necessary. This culture of technical scrutiny helps prevent incidental or erroneous measurements from steering the decision process and helps define the real risk on site more accurately.
Completion of the service does not end with the delivery of the report; the actions in the report must be implementable and traceable. Plan-Test links its recommendations to priority, the responsible discipline, the recommended due date, and the verification method. If the employer wishes, a scope for a technical meeting, post-correction check, or repeat measurement can be established for critical items. When new results are compared with historical data under the same equipment code, the facility's condition trend becomes visible. These records support the preparation of the future maintenance budget, spare parts plan, modernization decisions, and outage calendar. The goal is not to document a single project moment, but to build a corporate technical memory that contributes to safe operation and high availability targets throughout the energy facility's entire life cycle.
In every engagement, the relevant national legislation, the grid operator's requirements, IEC and IEEE standards, and the equipment manufacturer's instructions are considered together. While the general provisions of the standards are adapted to the facility's actual conditions, the contract and approved project requirements are also preserved. Where several criteria give different limits, the acceptance approach used is explained in the report; uncertain points are recorded with the employer as a technical decision. Using unique site codes instead of equipment names in documents strengthens traceability among drawings, test results, photographs, and actions. With this documentation discipline, Plan-Test aims to ensure that the technical evidence needed during an audit, provisional acceptance, warranty discussion, or a future failure investigation can be found quickly and reliably.
For the site program you need, it is sufficient to share the facility type, voltage level, equipment count, location, and target date. After the preliminary review, the technical team clarifies the appropriate scope, preparations, and delivery plan.