Transformer Maintenance

DigiVac vacuum instrumentation has many applications supporting utility and high energy and power applications.

DigiVac has been helping utility companies and companies that serve them for their vacuum needs.  Vacuum is used for transformer maintenance including transformer degas, transformer oil purification, transformer dryout and transformer leak detection.  DigiVac vacuum gauges and instrumentation are also used for conduit leak detection and leak trending.

Some of our customers use our model 200 to trend leaks in transformer. The sensor would be installed on the transformer, and the model 200 would be hooked up to a laptop on a nearby workstation or in a truck collecting data.  The initial absolute pressure (vacuum) would be recorded. Based on experience with known good transformers, an acceptable 24 to 72 hour leak rate will be established. If the final absolute pressure rise is within manufacturers tolerance, then the transformer could be considered sealed.Some of our utility service customers will use gauges like our model 200  or our portable vacuum gauge to help in the process of transformer dryout  and transformer oil purification.

Many of our customers use just a simple portable vacuum gauge to first make sure that the vacuum pumps that are being used are working properly.  Without a well running vacuum pump, evacuating a transformer or conduit could take many times longer.  See our simple example of verifying vacuum pump function (video below).

Dielectric oil will invariably be a part of doing high power transformer or conduit work. While the Agilent 531 thermocouple tube is a robust and economical choice sensor for this work, basic safeguards should be taken to make sure readings are correct and the sensor isn’t compromised. Make sure the sensor is vertically distant from oil and oil vapor. An example of how to do this is illustrated in DigiVac’s sensor siphon. Installing this plumbing between the sensor and vacuum interface helps mitigate oil travel to the sensor. Common plumbing can also be use to achieve this result.