1.1 Precise Positioning to Eliminate Protection Blind Zones
Horizontal Distance Requirements
Arresters shall be installed adjacent to protected equipment (e.g., transformers, switchgear) with a horizontal distance ≤5 m.
Installation Height Calibration
The height from arrester base to ground shall be ≥4 m (tolerance ±50 mm), calibrated by a laser rangefinder.
Foundation Fixation
Concrete foundation strength shall be ≥C30, with anchor bolt preload torque of 300 N·m (tolerance ±5%).
1.2 Grading Ring Installation
Dimensional Control
Dual grading rings spacing shall be 300±2 mm, with diameter error <5 mm (calibrated by a laser alignment instrument).
Material Selection
Corrosion-resistant 6063-T5 aluminum alloy with anodized surface treatment shall be used.
1.3 Lead Connection
Conductor Specification
TJ-50 copper stranded wire (cross-sectional area 50 mm²) shall be employed for its high conductivity and corrosion resistance.
Bolt Tightening
Torque shall be strictly controlled at 45 N·m±5% (verified by a digital torque wrench). Insufficient torque may cause overheating, while excessive torque risks thread damage.
Contact Surface Treatment
CX-12 power grease (temperature resistance -40~200℃) shall be applied to prevent oxidation-induced contact resistance increase.
Focused inspection is required when the temperature difference exceeds 10 K (e.g., 35℃ on one phase vs. 25℃ on others).
Key Inspection Areas
Prioritize inspection of flanges, grading rings, and other heat-prone areas.
2.2 Annual Health Check
Leakage Current Measurement
Measure leakage current under dry conditions, with a baseline value ≤2 mA. A sustained increase may indicate internal moisture or valve plate aging.
Data Comparison
Replacement is recommended if annual leakage current growth rate exceeds 20% compared to historical data.
3.1 Tool Upgrade
Equip laser alignment instruments and digital torque wrenches to ensure installation precision.
3.2 Data Management
Establish a health record for each arrester, documenting all test data for trend analysis.
3.3 Environmental Adaptation
Coastal Areas
Apply anti-pollution flashover coating (e.g., RTV-II) every 2 years.
High-Humidity Areas
Install breathers to prevent internal condensation.
Standardized maintenance extends arrester service life to 25 years and reduces unplanned outage losses by over 60%.