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When should the Corrosive Sulfur Test be performed? - Part 2

When thinking about when the Corrosive Sulfur test should be performed, it helps to consider the operating conditions of the transformers that have actually failed due to corrosive sulfur. Therefore, as a general guideline, if a mineral oil-filled transformer was manufactured or retrofilled since about the year 2000, and if it spends at least six months of the year with its top oil at a minimum of 70°C, then we recommend that the oil be tested for corrosive sulfur.

AGE Testing - Part 2

After the AGE test, the amount of acid remaining is measured, giving an indication of concentration of AGE in the sample. The result is compared to three calibration standards that are also run with the same procedure: a clank, a 1000 ppm AGE standard, and a 2000 ppm AGE standard. The response of the sample is compared with the response of the three standards to determine the concentration of AGE in the sample.

What is the AGE Test and when should it be performed? - Part 1

As perchloroethylene fluid ages in service, it breaks down and forms hydrochloric acid. The AGE additive acts to neutralize this acid, so that the acid does not react with the metals in the transformers.

Testing for Liquid Power Factor in Mineral Oil - Part 1

Liquid power factor is an outstanding tool for evaluating in-service transformer oil. The test is valuable for acceptance testing of new oil from a supplier, and for evaluating conditions in newly installed equipment. For in-service oil, there are several adverse conditions that can be discovered from the liquid power factor results.

PCB Testing - Part 1

In Part 1 of a two-part series on PCB testing, we will present some background information on PCB's, address when PCB testing is appropriate, and describe how a typical laboratory may perform PCB testing.

Moisture in Transformers - Part 1

There are several methods for dehydrating oil in a transformer while simultaneously attempting to dry the paper insulation. However, drying the insulation (the most important step) is much more difficult than just dehydrating the oil. 

Testing Furanic Compounds in Insulating Liquids - Part 1

Furans form when the paper that makes up the solid insulation breaks down or depolymerizes. When this happens, the cellulose molecules break into shorter polymer chains and kick out a glucose monomer molecule. As this happens, the average polymer chain length in the paper (which can be measured and reported as the degree of polymerization. or DP) decreases. Shorter polymer chains result in weaker paper.

Dielectric Breakdown Voltage Testing - Part 1, Standard Methods

What causes bad D1816 dielectric breakdown voltage values? The first article in this series will discuss the three standard methods that SDMyers is equipped to perform, and why we perform them for our customers. There are two standard methods from ASTM International: D877, Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes, and D1816, Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Using VDE Electrodes. 

What is the Corrosive Sulfur Test? - Part 1

The Corrosive Sulfur test is a laboratory test performed on electrical insulating liquids of petroleum origin that detects the presence of corrosive sulfur in the sample. In Part 1 of this three-part series on the Corrosive Sulfur test, we will define corrosive sulfur, briefly review the history of the issue, and describe how corrosive sulfur can cause a transformer to fail.

Risk & Reliability of Transformers

A significant and growing risk for unplanned outages and lost production has been increasing in the past decade due to failures of critical power transformers. With plant capacity running at all-time highs in the US and little room for unplanned outages, it is more critical than ever that transformer reliability become front and center of any effective reliability program. 

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