Installation and Maintenance Guide for European-Style Prefabricated Substations

European-style prefabricated substations are essential components in modern power transmission and distribution systems. Thanks to their high integration, compact structure, and excellent operational reliability, they are widely used in industrial parks, residential areas, municipal projects, and commercial facilities. Proper installation directly impacts performance, while systematic maintenance ensures safety, minimizes failures, and extends service life. This guide provides standardized instructions for installation, inspection, and maintenance of European-style prefabricated substations.

Pre-Installation Preparation

Site Selection Requirements

Choose elevated locations with good drainage and avoid low-lying areas prone to flooding. The substation must be far from fire hazards, explosive environments, chemical corrosion, and heavy vibration zones. Ensure good ventilation, allow enough clearance for doors and equipment movement, and keep transformer room doors unblocked.

Foundation Construction Standards

Build a reinforced concrete foundation based on the equipment’s weight and dimensions. Keep horizontal deviation within 5 mm and pre-reserve cable and grounding channels. Install protective barriers to prevent rodents or small animals from entering beneath the unit.

On-Site Equipment Inspection

External Check: Inspect enclosure, transformer, and switchgear for damage or deformation; confirm anti-corrosion coating integrity.
Internal Testing: Verify firm electrical connections, neat wiring, and functional interlocks. Insulation resistance for 10 kV windings should be ≥10 MΩ.
Documentation: Confirm model, wiring diagrams, and packing list match factory records.

Installation Procedures

Lifting Operations

Use cranes or certified lifting straps, attaching to designated lifting points. Keep the substation stable and avoid collisions. Ensure lifting rope angles do not exceed 60°.

Positioning and Fixing

Align the unit with a level, adjust using shims, and secure with anchor bolts. Follow design requirements for bolt type and tightening torque.

Cable Connections

Cable Selection: Match cable type and specification with design. Cable ends must comply with standard processes.
Busbar Connections: Follow phase color codes (A: green, B: yellow, C: red). Maintain safe distances: ≥125 mm clearance and ≥240 mm creepage for 10 kV systems.
Grounding: Connect enclosure, neutral point, and switchgear bus to grounding electrodes. Copper grounding conductors must have at least 25 mm² cross-sectional area.

Grounding System Installation

Use 50 × 5 mm angle steel electrodes, at least 2.5 m long, spaced ≥5 m apart. Apply resistivity-lowering agents to achieve grounding resistance ≤4Ω.

Maintenance Guide

Routine maintenance is critical for safe, efficient, and long-term substation operation. Proper inspections prevent costly downtime and equipment failure.

Recommended Maintenance Intervals

Visual Inspection: Monthly or more frequently under harsh conditions.
Routine Maintenance: Every 6–12 months.
Comprehensive Overhaul: Every 3–5 years depending on operational load.

Daily / Visual Inspection

Check enclosure for rust or deformation, confirm clear labeling, and ensure doors/windows are sealed. Listen for abnormal transformer noises and vibrations. Record voltage, current, frequency, and power factor. Monitor temperature and humidity, and test dehumidifiers if installed. Inspect safety devices such as pressure relief valves and gas relays for signs of failure.

Routine Maintenance

Power-Off Cleaning: Remove dust, cobwebs, and debris, especially on insulators and bushings. Use a vacuum or dry compressed air.
Connection Tightening: Retighten bolts on busbars, cables, and breakers using a torque wrench.
Component Checks: Inspect circuit breakers, fuses, and arresters in HV rooms. For oil-immersed transformers, check oil levels and leaks; for dry-type, check windings and cooling fans. In LV rooms, test circuit breakers, compensation capacitors, and contactors.
Insulation Testing: Measure insulation resistance and compare with historical records.
Grounding Inspection: Check all grounding points for corrosion, verify resistance when necessary.
Functional Tests: Test protective devices, alarm functions, and automatic transfer switch (ATS) performance.

By following standardized installation and maintenance procedures, operators can ensure that European-style prefabricated substations deliver reliable, safe, and efficient performance throughout their service life. From site selection and foundation building to cable connections and long-term maintenance, every step plays a vital role in optimizing substation operation.