PSI Organisation & Transformer Maintenance — Traction Distribution Notes

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The divisional PSI setup under Sr.DEE/DEE(TrD) follows one of two patterns: territorial (one subordinate responsible for ALL activities across a section/sub-division) or functional (separate subordinates in charge of each specific activity — sub-station, OHE, workshop, PSI, etc.). Remote control and protective relay testing are specialised activities, so SSE(RC) and SSE(Test Room) usually have functional jurisdiction across the ENTIRE division, headquartered at the Remote Control Centre and Divisional Repair Shop respectively — meaning territorial SSEs must maintain constant liaison with them for these dual-control aspects.

SSE(PSI) — Real Duty List

SSE(PSI) is the senior supervisor under DEE/AEE(TrD), directly responsible for safe/efficient operation and maintenance of all traction power supply installations in jurisdiction (sub-stations when railway-owned, switching stations, auxiliary transformers). Real, numbered duties:

Supervise maintenance per prescribed schedules to keep installations fully operational and in good condition at all times.
Maintain proper coordination with TPC, SSE(OHE), and Supply Authorities for supply reliability.
Keep the organisation in constant readiness to deal promptly with breakdowns and equipment failures.
Ensure the protective-relay testing/maintenance programme is adhered to, and other safety equipment (bonding, earthing) functions effectively.
Instruct/train/supervise staff to ensure they don't improperly operate/maintain equipment, and actually observe rules, regulations, and safety precautions.
Depute staff for refresher courses, particularly those found deficient in their working.
Ensure special instruments/tools for maintenance/operation/testing are properly cared for.

Transformer Condition Monitoring

In oil-filled equipment, insulation deteriorates via thermo-chemical reaction involving heat, moisture, and oxygen — forming insoluble products that degrade oil and cellulosic insulation properties. Oil can be reconditioned, but cellulosic insulation cannot be treated once its mechanical/dielectric strength reduces.

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Exam Focus — The Real Flash Point Drop

Thermal/electrical stress from short circuits, overloads, and over-voltages causes gas formation and drops oil flash point from a normal 145°C down to somewhere between 50°C and 80°C in extreme deterioration cases — a real, specific number range worth remembering. Critically, the Buchholz relay CANNOT respond during the early/incipient stage of such faults — by the time it does trip, the damage is already done.

Dissolved Gas Analysis (DGA) via Gas Chromatography (GC) is the most efficient, rapid method for detecting incipient/growing faults NOT always revealed by routine tests — since gases from incipient faults are soluble and absorbed in the oil. To catch insulation deterioration in time, an oil sample should be drawn ANNUALLY and subjected to gas chromatography.

Transformer Overhaul — Real Practices

Overhaul is undertaken when a fault develops, OR periodically at 7-10 years — done at the Central Repair Shop (a covered shop with core-lifting crane bay).
If opened due to an internal fault, carefully note oil colour, arc-marks, carbon deposits, winding condition, unusual odour — these help ascertain the failure's cause. A burnt-out coil requires complete dismantling; damaged coil replacement for traction transformers is best done at the Manufacturer's works with the requisite skills.
If coil assembly is lifted after 5, 10, or more years of service, considerable sludge accumulates on tank bottom, metalwork, windings, and inter-spaces — scrape off carefully with a WOODEN or FIBRE wedge only (never metal, to avoid winding damage); a thin jet of transformer oil under pressure clears sludge from inaccessible spots.
Windings must be protected against moisture ingress, especially in humid weather — wipe off body sweat with a towel, and keep open windings warm using infrared lamps or other means.