MAINTENANCE OF MV STATIONS
Keeping the flow stable - Professional MV substation maintenance
1. Preventive Maintenance (scheduled)
Visual Inspections: Check for corrosion, oil leaks, unusual noise, cracks in insulators.
Cleaning: Dust, salt, or bird droppings can cause tracking and flashovers.
Tightening connections: Prevent overheating and arcing at busbars, terminals, and grounding points.
Testing protective relays: Ensuring protection systems (overcurrent, differential, distance relays) work correctly.
Lubrication: Moving parts of disconnectors and circuit breakers.
2. Predictive Maintenance (condition-based)
Thermographic Inspections (infrared cameras): Detect hot spots in connections and transformers.
Oil analysis of power transformers: Dissolved gas analysis (DGA) reveals insulation aging or faults.
Partial discharge (PD) testing: Identifies insulation defects in cables and switchgear.
Online monitoring: SCADA systems track load, voltage, breaker operations, and alarms.
3. Corrective Maintenance (unscheduled)
Replacing failed fuses, surge arresters, or transformers.
Repairing protection/control equipment after faults.
CRITICAL EQUIPMENT WE MAINTAIN
Power transformers: Oil levels, bushings, tap changers.
Gas-Insulated switchgear (GIS) or Air-Insulated switchgear (AIS): SF gas monitoring (for GIS), breaker mechanism tests.
Circuit breakers: Timing tests, contact resistance checks.
Protection relays & SCADA systems: Firmware updates, calibration.
Grounding system: Measure soil resistance, inspect ground connections.
Auxiliary systems: Batteries, chargers, HVAC for control rooms.
MAINTENANCE INTERVALS
Monthly/Quarterly: Visual checks, SCADA data review, thermography.
Annually: Protection relay testing, transformer oil sampling, breaker mechanism tests.
Every 3–5 years: Comprehensive transformer diagnostics, circuit breaker overhauls.