Switchgear removal in Korean substations means safely removing breakers, disconnectors and their accessories. It is not just demolition: work is often done next to live equipment, SF6 must not be released to the atmosphere, and equipment for reuse has to be separated in reusable condition. This guide covers two stages: preparation and removal.
Contents
- Common Pre-Work Review
- 1. Preparing for Removal
- 2. Removing Switchgear
- NCS Removal and Transport Criteria
- FAQ
- Reference Standards
- Summary
Common Pre-Work Review
Review the manufacturer’s manuals, KEPCO’s GIS removal standard, transmission and substation safety rules and the construction, quality, environmental and safety plans. Identify live and dead parts; keep safe clearance near live parts, and earth equipment and rope off outage sections. Prepare an SF6 recovery unit, storage tank, gas analyzer and mobile crane. Gas port designs differ by manufacturer, so check the connection and use the right adapter when recovering gas.
1. Preparing for Removal
- Inspect the exterior and structure of the GIS, GCB or other switchgear.
- Measure gas purity and moisture before removal to decide on reuse.
- Decide how to remove the main body, taking service life into account.
- Prevent breakers and disconnectors from closing, and prevent inspection covers in live zones from being opened.
When operating equipment, always check the related interlocks and links to other equipment to avoid mis-operation into live zones.
2. Removing Switchgear
- Remove switchgear unit by unit according to the removal plan.
- Seal separated joints and fill with gas so contaminants cannot settle.
- Check live status before and after work.
- Remove equipment safely, considering how it operates.
- Prepare removed equipment to transport conditions and load it with a crane of suitable capacity.
NCS Removal and Transport Criteria
| Item | Criterion |
|---|---|
| Working conditions | Humidity 80% or less; wind 10 m/s or less |
| Transport position | CB open (closed for some manufacturers), DS and ES closed |
| Transport gas pressure | 0.2–0.5 kg/cm² |
| Impact recorder | 3 G or less longitudinal, vertical and lateral |
| Impact indicator | Ball not released or dislodged; arrow aligned |
| Reuse decision | Gas purity and moisture measured before removal |
| SF6 | Recovered with a recovery unit; no atmospheric release |
These values come from the considerations in the NCS competency unit. Reuse decisions follow the client’s instructions.
FAQ
Why measure gas purity and moisture before removal?
The results show whether the equipment can be reused; if it is in good condition it may be redeployed elsewhere.
Why fill separated joints with gas?
Moisture and contaminants on open joints make reuse difficult. Sealing and filling with gas protects the inside.
What needs most care next to live equipment?
Prevent breakers and disconnectors from closing and live-zone covers from being opened, and check interlocks and links between devices before work.
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)
- NCS competency unit Substation Switchgear Removal (개폐장치 철거공사, 1901070328_22v2; NCS is Korea’s National Competency Standards) — ncs.go.kr
Summary
The most common mistakes are operating without checking interlocks to adjacent live zones and opening compartments without recovering SF6. Preparation depends on reuse checks and preventing closing or opening; removal on unit order, sealed joints, live checks and meeting transport criteria. Related guides: Substation Switchgear Installation, Main Transformer Removal, Switchgear Overhaul Maintenance. A Korean version of this guide is available here.
This article restructures the Korean NCS competency unit ‘Substation Switchgear Removal’ (개폐장치 철거공사, code 1901070328_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