IoTx prevented a Transformer shutdown and probable explosion saving huge revenue loss
Most of us know the role of Transformer oil in the overall functioning of a Transformer. The theory also says that an inadequate level or leakage of transformer oil could lead to major mishap affecting assets, as well as human safety. This theory became a reality in one our customer's case with a 315 kVA transformer installed at their manufacturing facility. Motwane's IoTx - A Digital Transformer monitoring system helped them identify an oil leakage in the conservator, which might have led to the transformer shutdown and probable explosion affecting human safety & huge revenue loss, had it gone undetected. IoTx monitors critical transformer parameters on a real-time basis & gives alarm/notification in case of any anomalies.
This 315 kVA transformer has an IoTx installed. In the absence of IoTx, it could have been impossible to detect an oil leakage, unless a physical inspection is carried out. It could also be difficult to detect the exact location of leakage by correlating loading conditions & oil level.
Root cause & issue identified by IoTx (Digital Transformer Monitoring Unit)
Issue - Oil Leakage from Transformer
Earlier when this issue was raised on 4th December, 2019; the quantity of oil filled in the conservator was recorded at 60% of the conservator’s total oil level.
- 1st issue of low oil level in the conservator was observed on 11th Dec, 2019 by IoTx.
- Since then IoTx monitored the oil level in conservator every 5 minutes, until it was refilled and leakage issue was resolved on 23rd Jan, 2020.
Oil Level was below the set limit but due to contraction and expansion of the oil. This level used to rise above-set limit for a specific amount of time, majorly in the day time when the loading on the transformer was more and the ambient temperature was high.
- It was found that Oil level was below-set level every day from 9 p.m. to 1 p.m.; this might be because of less loading on the transformer and low ambient temperature.
- It was also found that Oil level was above-set level every day from 1 p.m. to 9 p.m., this might be because of more loading on the transformer and high ambient temperature.
By virtue of streaming data available through IoTx, we plotted a graph of the gradient of oil temperature rise w.r.t % loading. The purpose of the below graph is to establish a correlation between the loading of the transformer & the rise in oil temperature.
The above two graphs depicted that the gradient of oil temperature rise w.r.t. % loading was near about the same i.e. 42℃ for 41% to 50%, this signified that the oil level in the transformer tank was good.
Hence, it was confirmed that the oil leakage issue was only at the conservator of the transformer.
SAVED Transformer from following Possible Anomalies
- The oil level in the transformer tank could have decreased, which might have ultimately resulted in heating the transformer winding and transformer oil.
- Air bubbles and impurities in oil could have increased, which might have decreased the oil quality and an insulation breakdown.
- The transformer winding might have burned out due to the high winding temperature, which could have been a huge monitory loss.
- Also, due to downtime revenue loss could have happened.
Ultimately saved the transformer & revenue loss by the virtue of IoTx
- Beyond Repair - Transformer Price/ Replacement Cost(Approx.): INR 2,50,000 - INR 2,80,000
- Repairing Cost/ Winding Replacement/ Oil Replacement approximate cost: INR 80,000-INR 1,20,000
- Saved 30% of Transformer Oil
- Revenue Loss due to Transformer Failure: Per day production Loss( Varies case to case basis)