Substation inspection and completion in Korea covers passing the statutory pre-use (pre-energization) inspection, processing completion and handing the facility over to the client once construction is finished. Without passing the pre-use inspection the equipment cannot be energized, and missing completion documents complicate payment and defect management. The key is to build up test results and records at each stage rather than producing them all at the end. This guide covers three stages: pre-use inspection, completion and handover.
Contents
- Common Pre-Work Review
- 1. Pre-Use Inspection
- 2. Completion
- 3. Facility Handover
- Documents by Stage
- FAQ
- Reference Standards
- Summary
Common Pre-Work Review
Review the Electricity Business Act, Electrical Safety Management Act, Electric Technology Management Act, Electrical Construction Business Act, Construction Technology Promotion Act, the KEC, the substation standard work procedures and supervision standards. The method statement (quality test, environmental, material and safety plans) and the approved quality test plan are the baseline. If the work required construction plan approval or notification, confirm from the start whether it is subject to pre-use inspection and what documents are needed.
1. Pre-Use Inspection
- Carry out stage-by-stage tests in line with the design and the approved quality test plan.
- For foundations, prepare concrete, soil and material test records taken at hold points.
- Check insulator string assembly, inclination and clearances to protective devices and supports against the clearance measurement report.
- Check workmanship and earth resistance against the earth resistance report.
- Confirm interlock testing between power circuit breakers and protective relays using the line breakers.
- Confirm compliance with the Technical Standards for Electrical Equipment, including measures against induction interference on protection communications.
- Test control, metering and protection devices to the test records and protection criteria, and confirm alarms operate immediately on detecting a fault.
- Apply to the Korea Electrical Safety Corporation (KESCO) for pre-use inspection under the relevant laws, submitting the application and documents after client confirmation.
- Attend the inspection and correct any findings immediately.
2. Completion
- Fully address findings from the pre-completion inspection, then prepare and submit the completion inspection request.
- Submit as-built design documents at least one month before the completion date for the supervisor’s review.
- Have the site representative attend the completion inspection, correct any rework items and arrange re-inspection.
Completion inspection checks that work matches the design, the resident supervisor’s records, disposal of waste, use of supplied materials and surplus, removal of temporary works and reinstatement, and the supervisor’s review opinion.
3. Facility Handover
- Plan the handover so the client can maintain the facility, and keep to the schedule.
- Agree the list of handover documents with the client, then prepare and submit them.
- After completion, prepare the maintenance manual the client requests and plan for defect repairs.
The handover plan covers the project overview, single-line diagram, layouts, material usage and surplus or removed materials, inspection records, permits, photos and video, and special notes.
Documents by Stage
| Stage | Main documents |
|---|---|
| Pre-use inspection specifications | Power transformer, bus, circuit breaker, control, ancillary, station transformer and central monitoring specifications |
| Pre-use inspection checklists | Power transformer, bus, breaker, reactive compensation, central monitoring, ancillary and earthing checklists |
| Pre-use test reports | Transformer, breaker, control and metering, pressure switch and compressor, protection, reactive compensation reports; bus checklist; phase rotation and loop tests |
| Pre-use inspection application | Application form, copy of construction plan approval or notice, copy of safety manager appointment, etc. |
| Completion inspection | Electrical and fire work confirmations, power supply contract, plan approvals, pre-use and fire inspection certificates, KS material summary, supervision report, defect liability bond, etc. |
| Handover after completion | Completion photo album, as-built drawings and bill, specifications, shop drawings, test reports, procurement records, work logs, handover form, completion report, supervision log, maintenance manual |
This list summarizes the NCS considerations. Actual documents depend on the contract and the inspection body’s requirements.
FAQ
Where is the pre-use inspection applied for?
For electrical facilities with an approved or notified construction plan, apply to the Korea Electrical Safety Corporation under the relevant laws, after client confirmation.
When are as-built documents submitted?
The NCS says at least one month before the completion date, for the supervisor’s review.
What if the pre-use inspection finds problems?
Attend the inspection and correct findings immediately. Having stage test results and measurement reports ready in advance reduces findings.
Reference Standards
- Electricity Business Act (전기사업법) — law.go.kr
- Electrical Safety Management Act (전기안전관리법) — law.go.kr
- Electric Technology Management Act (전력기술관리법) — law.go.kr
- Electrical Construction Business Act (전기공사업법) — law.go.kr
- Occupational Safety and Health Act (산업안전보건법) — law.go.kr
- Korea Electro-technical Code (KEC, 한국전기설비규정) — law.go.kr
- Technical Standards for Electrical Equipment (전기설비기술기준) — law.go.kr
- KEPCO design standards and substation construction practice; Korean Industrial Standards (KS)
- Construction Technology Promotion Act (건설기술진흥법) — law.go.kr
- Framework Act on the Construction Industry (건설산업기본법) — law.go.kr
- NCS competency unit Substation Inspection and Completion (변전설비 검사준공, 1901070321_22v2; NCS is Korea’s National Competency Standards) — ncs.go.kr
Summary
The most common mistakes are assembling test records just before the pre-use inspection and submitting the completion request before pre-completion findings are fully fixed. The pre-use inspection depends on stage test records and interlock tests; completion on the timing of as-built submissions and closing findings; and handover on an agreed document list and the maintenance manual. Related guides: Substation Construction Management, Substation Site Execution Management, Quality, Safety & Environmental Management. A Korean version of this guide is available here.
This article restructures the Korean NCS competency unit ‘Substation Inspection and Completion’ (변전설비 검사준공, code 1901070321_22v2) as a practical reference. Actual work must follow applicable standards and the judgment of qualified professionals; always confirm specific values, deadlines and criteria against the latest regulations and client standards.
Written/reviewed by VOLT · Last updated 2026-10-26