This is the real checklist an inspecting officer works through during a traction sub-station visit — organised by area (switch yard, power transformer, circuit breaker, PT/CT/AT, isolator, control panel, battery, earthing, remote control, and general items), feeding directly into the real monthly inspection quota table covered in the previous chapter.
Switch Yard & Power Transformer
- Switch yard: vegetation growth/spreading pebbles, painting of fencing/equipment, cable trench/trench-cover condition, approach road condition.
- Power Transformer: O.T.I. (Oil Temperature Indicator) and W.T.I. (Winding Temperature Indicator) — both present AND maximum readings; oil level in conservation tank; tap-changer position of BOTH the standby and in-service transformer; any abnormal humming; colour of silica gel; oil leakage on body/conservator tank/drain valve/radiator.
Exam Focus — Checking BOTH Transformers' Tap Position
The inspecting officer checks tap-changer position of BOTH the standby AND the in-service transformer — not just the running one. This matters because if the standby transformer's tap is misaligned with the in-service one, switching over during an emergency (covered in the earlier Protective Devices chapter's parallel-operation discussion) could introduce a voltage mismatch at exactly the wrong moment.
Circuit Breaker, Interrupters & PT/CT/AT
- Control box gaskets for water/dust tightness; operation by BOTH local and remote control; smooth operating mechanism; oil level/leakages; closing time of interrupter.
- Number of trippings since last oil replacement (for circuit breaker), and counter reading of the interrupter — real tracked figures feeding into the overhaul-trigger thresholds covered in the SF6 Breaker chapter.
- PT, CT, AT: check for oil leakage.
Isolator & Control Panel
- Isolator: locking arrangements, correct blade-tip alignment in fixed contact jaws, correct matching/alignment of arcing horns.
- Control panel: fuses for correct size and overheating/aging signs, loose terminal-board connections, alarm/visual-indication functioning, auxiliary relay functioning.
Battery Charger & Batteries
A real 7-point check that mirrors the Station Batteries chapter: acid level, presence of sedimentation, specific gravity/voltage of the pilot cell, presence of sulphation and tightness of inter-cell connectors, size of battery-charger fuses, voltmeter/ammeter readings, and an energy-meter check with recorded maximum demand.
Earthing, Remote Control & General Items
- Earthing: soundness of earth connection to EVERY electrical equipment and structure, last recorded earth-resistance readings, and buried rail connection.
- Remote control equipment: general function of relays/selectors, any loose-connection wiring, dust presence, and cubicle gasket condition.
- Condition of the seal (a distinct, single checklist item — checking whether tamper-evident seals are intact).
Exam Focus — The Real General Checklist
The checklist's final 'General' category has 4 real items: availability of fire buckets/respiration chart/First Aid Box/Tools & Plants; working of TPC phones and emergency sockets (directly matching the Remote Control & Communication chapter's real 0.75-1km emergency socket spacing); the Inspection Register and remarks made in it; and history sheets of various equipment. These 4 items are what tie the whole inspection process together into a documented, auditable trail.