| Accessory | Transformer Type | Applicability | Notes | Actions |
|---|---|---|---|---|
| Buchholz Relay | ONAN | KVA ≥ 100 | Required by IS 2026 | |
| Marshalling Box | All | All ratings | Standard on all units | |
| Pressure Relief Valve | ONAN | KVA ≥ 250 | Safety requirement | |
| MOG (Magnetic Oil Gauge) | All | All ratings | — | |
| Explosion Vent | ONAN | KVA ≥ 500 | IS 1180 clause 9 | |
| Wheels | All | KVA ≥ 200 | Bidirectional | |
| Thermometer (OTI/WTI) | ONAN | KVA ≥ 500 | Dual sensor preferred | |
| LV Busbar Chamber | Dry Type | All ratings | — | |
| Bus Duct Flange | Dry Type | KVA ≥ 500 | Customer spec dependent | |
| LV-CT (Current Transformer) | ONAN | KVA ≥ 1000 | For metering | |
| OLTC (On-Load Tap Changer) | ONAN | KVA ≥ 250 | Auto/manual toggle | |
| Air Release Plug | ONAN | All ratings | Required post-tanking |