After filling a transformer, how long should you wait before energizing it?

When filling a transformer with oil, waiting for an appropriate duration before energizing it is essential to ensure that the oil has settled and all air bubbles have been adequately dissolved. This waiting period allows for the oil to circulate within the transformer, ensuring that any contaminants or air trapped during the filling process can either rise to the top or be filtered out, enhancing the performance and reliability of the transformer.

Selecting a 48-hour waiting period is a prudent choice as it provides ample time for any dissolved gases to escape and for the oil to achieve proper dielectric strength. This duration helps to minimize the risk of electrical failure due to inadequate insulation caused by air entrapment or other anomalies. In many industrial practices, a minimum of 48 hours is often recommended to ensure optimal conditions for safe operation.