Transformer Oil Testing Service

  • By Aman Ullah
  • Published in Services
  • Jul 20, 2023
  • 3.91 Min
Transformer Oil Testing Service

Transformer Oil Testing Service

Transformer Insulating Oil is used in the transformer for insulation and cooling purpose. The transformer oil is obtained by fractional distillation and subsequent treatment of crude petroleum and the transformer oil is also known as Mineral Insulating oil. In this article, we will discuss in detail transformer oil testing, its types, and properties.

Monitoring and maintenance of oil quality are essential to ensure the reliable operation of oil-filled electrical equipment. Codes of practice have been established in many countries that include tests for Tan Delta, Relative Permittivity, and Resistivity.

While a transformer is in operation, oil is subjected to electrical and mechanical stresses. Additionally, contamination occurs as a result of chemical reactions between windings and other solid insulations, which are catalyzed by extremely high temperatures.

As a result, the original chemical properties of Transformer Oil change gradually, rendering it ineffective for its intended purpose after many years. Hence this oil has to be periodically tested to ascertain its basic electrical properties and make sure it is suitable for further use, or necessary filtration/regeneration has to be done.

Figure: Oil BDV Tester 75KV, 100KV, Oil Tan Delta and Resistivity Tester 100KV

Iconic scope of testing Oil BDV, Tan Delta, Relative Permittivity, and Resistivity

Our expert engineers used world-class Oil Test Sets, which measure BDV (Breakdown Voltage), Tan Delta, resistivity, and relative permittivity of insulating oils. It is a fully automated system and comes loaded with a set of international test standards such as IEC 60247:2004, IEC 61620:1998, ASTM D924-08, ASTM D1169:2002, BS 5737:1979, JIS C2101:1999, VDE 0380-2:2005_01, IS 6262:1971, IS 6103:1971, As well as the international set of standards, it supports up to six customer configurable test sequences. It has a 12-key alpha-numeric keypad to facilitate the entry of test IDs, filenames, notes, etc. Test results can save by a test ID and time and date-stamped. It has an Ink-based printout that ensures durability at all temperatures. User safety is also paramount. We can perform up to 100KV Oil Breakdown Voltage Test as well as 100KV Tan Delta and Resistivity Testing using a world-class Oil Test Set.

Features and Benefits of Iconic Oil Testing

  • Fully automated test sequences
  • 16 pre-installed international standards
  • 6 user-programmable sequences
  • Test Cell heating up to 110 °C with uniformity across the cell IEC 60247
  • Oil drain facility - manual and fully automated microprocessor controlled
  • Internal impact printer - automatically prints at the end of a test or manually if preferred

APPLICATION

  • New oil reception - quality test
  • Regeneration of oil - quality test
  • Monitoring and maintenance of oil quality in the oil-filled electrical equipment
  • Transformers
  • Switch Gear
  • HV Cables

What is the Tan Delta Test?

Tan Delta testing, also known as Dielectric Dissipation, Loss Angle, or Power Factor testing, is used to determine the quality of insulating oil. This type of testing is conducted at two different temperatures. The results of the two tests are compared, and then the coil's quality level is considered. If the test findings are satisfactory, the oil is kept in service; if the test results are not satisfactory, either a replacement or a change of oil is taking place.

Tan Delta and Resistivity Testing

Oil tan delta and resistivity testing are two more critical parts of transformer oil testing. They are measures of the oil's insulation properties and can help identify potential transformer issues. Here are some important aspects of oil tan delta and resistivity testing:

  1. Purpose:
    The Purpose of oil tan delta and resistivity testing is to evaluate the insulating qualities of transformer oil and detect potential issues such as contamination or degradation.

  2. Test Procedure:
    The oil tan delta testing process comprises applying an alternating current voltage to the oil and measuring the phase angle between the applied voltage and the resultant current. The resistivity test process involves evaluating the oil's resistance to the flow of electric current.

  3. Standards:
    Various standards and regulations outline the test technique and acceptance criteria for oil tan delta and resistivity testing. For example, the ASTM D924 standard specifies how to test the dielectric strength of insulating oils.

  4. Specialized equipment:
    is necessary for oil tan delta and resistivity testing, including a voltage source, electrodes, and a test cell. The test cell is filled with transformer oil, and the electrodes are positioned to impart voltage across the oil.

  5. Interpretation:
    The findings of oil tan delta and resistivity tests should be understood in the context of the transformer's operating parameters and historical data. Changes in the oil's tan delta or resistivity over time may indicate contamination, deterioration, or other concerns that require attention.

In conclusion, oil tan delta and resistivity testing are important aspects of transformer oil testing and should be performed regularly to ensure the safe and reliable operation of the transformer. It is important to follow standardized procedures and interpret the results in the context of the transformer's operating conditions.

Oil BDV Testing

The testing of oil breakdown voltage is an important part of transformer oil testing. It measures the oil's dielectric strength, or its capacity to endure electric stress without degrading. The following are some important characteristics of Oil Breakdown Voltage testing:

  1. Purpose:
    The purpose of oil breakdown voltage testing is to guarantee that the transformer oil has enough insulating characteristics and can execute its role of insulating and cooling the internal components of the transformer.

  2. Test Procedure:
    A voltage is applied to the oil and steadily increased until the oil breaks down and an electrical spark is generated. The voltage at which the breakdown takes place is measured and recorded.

  3. Standards:
    The test technique and acceptance criteria for oil breakdown voltage testing are specified in several standards and regulations. The ASTM D1816 standard, for example, sets rules for evaluating transformer oils.

  4. Equipment:
    Oil breakdown voltage testing necessitates the use of specialized equipment such as a voltage source, electrodes, and a test cell. The transformer oil is filled into the test cell, and the electrodes are positioned to impart voltage across the oil.

  5. Interpretation:
    Oil breakdown voltage testing findings should be evaluated in light of the transformer's operating parameters and historical data. A reduction in oil breakdown voltage over time may suggest contamination, degradation, or other concerns that need to be addressed.

In conclusion, Oil breakdown voltage testing is an important aspect of transformer oil testing and should be performed regularly to ensure the safe and reliable operation of the transformer. It is important to follow standardized procedures and interpret the results in the context of the transformer's operating conditions

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