The analytical tests performed are used collectively to evaluate the progress of conditions that can damage your equipment or shorten its life. Equally important to your maintenance program is the way in which the results of the tests are presented. Central to the OLTT® program is the multi-colored test report we use to transmit our data and recommendations to you - the report that the industry has come to know as the "rainbow master."

One of the excellent features of our rainbow masters is that they include past history. Almost always, changes in test results from sample to sample are much more important than the absolute value of the most recent analysis. The interpretations and diagnoses that we make concerning test data are made with that past history in mind. The rainbow masters provide documentation of this past history and of the important nameplate and application information concerning the equipment to better allow the customer to understand and implement the monitoring and servicing recommendations.

The OLTT® package recommended for your particular piece of equipment takes into account your needs for information, the testing that has previously been done on the equipment, and the tests that provide the most cost effective response to the processes of ageing and contamination that are likely to occur. Naturally, the recommended package takes into account the type of equipment, size, age, and application of the unit, and the degree to which a particular unit is critical to continuation of your operation or production.

>> What tests are recommended for On-Line Transformer Testing®?

The selection of the appropriate package for your needs, and the recommended interval for testing, depends on the type of equipment, age and application of the equipment, and previous testing results. The following are some general guidelines we use for mineral oil filled equipment. Your S. D. Myers, Inc. representative should be consulting concerning your specific needs.

*Oil Screen Tests include: D877 dielectric breakdown, neutralization number, interfacial tension, specific gravity, color, visual examination

  
 
>> General Guidelines for Recommended OLTT® Testing by Equipment Type (Mineral Oil Filled Units)

*This recommended package and interval applies also to other special applications such as rectifiers and GSUs.
**The recommended routine monitoring interval for dissolved gas analysis will vary by size and age of the unit.
***The recommended package for LTCs includes a mini-OLTT, particle size analysis, particle type analysis, and analysis for filming and coking compounds.

>> What is our experience?

As a company, we have been testing transformer oil and providing interpretations of test results for 37 years. Our database of transformer test data exceeds four million records. Annually, we test tens of thousands of transformers, representing hundreds of thousands of insulating liquid samples. More than one half of our laboratory technical personnel have at least twelve years of experience with S. D. Myers, Inc., and the average level of experience for all technical staff is more than ten years. Results are reviewed and recommendations are prepared by a small group of specialists and supervisors who have, collectively, more than 100 years of laboratory and transformer maintenance experience. S. D. Myers, Inc. personnel are key contributors to the activities of many technical and trade organizations such as ASTM, IEEE, IEC, Cigre, NETA, and the Doble Client Committees.