- Insulation tests - Perform, interpret, and evaluate insulation tests including resistance, dielectric absorption, polarization index, tip-up, and applied voltage withstand.
- The Complete Guide to Electrical Insulation Testing [PDF] Essential reading to gain a solid understanding of electrical insulation and how to evaluate its condition.
- The Basics of Insulation Testing [PDF] Much like a leak in a water pipe, an imperfection in the insulation of a wire allows a steady flow of electricity to escape. This can be a detriment to electrical circuits and machinery.
- Understanding Insulation Resistance Test Methods There are three different tests that can be performed with the Megohmeter. A strong understanding of these common test methods is an important tool in gaining the ability to determine the condition and quality of electrical insulation.
- Corona Imaging - See the Invisible [PDF] Until recent technology breakthroughs, ultrasonic detection was one of the only methods capable for detecting corona.
- What is Partial-Discharge Resistance? [PDF] When voids are present in solid dielectrics and the electrical field is sufficiently high, air (or other gas) inside the voids ionizes and creates breakdown pulses across the voids. These pulses are referred to as discharges.
- Thermographic survey - Have the ability to perform, interpret, and evaluate a thermographic survey on electrical distribution systems. Interpret results in order to evaluate the condition of the equipment surveyed.
- Defining the Elements for Successful Infrared Thermography [PDF] To ensure optimum results, a thermographer needs to understand the nature and reason for the inspection, all equipment and operator limitations, site conditions, and the proper documentation of findings.
- Infrared Inspections and Applications [PDF] The infrared survey is a great initial screening or detection tool for potential problems, but additional electrical tests should be performed in order to confirm initial conclusions.
- The No-Outage Testing Matrix [PDF] This article is aimed at helping target the best no-outage testing methods for various types of electrical equipment through the use of a simple matrix.
- Infrared Inspection Data: What's hot and what's not? [PDF] Learn about standard methodologies for conducting the infrared inspections.
- Introduction to Infrared Thermography [PDF] Infrared thermography is a proactive troubleshooting and predictive maintenance tool. In the hands of a thermographer an infrared camera can be used to make the world that is invisible to the human eye come to life
- Ratio and relative polarity - Correctly apply voltage or current to one set of windings and measure the output of associated windings to determine ratio, polarity, and/or phase relationship. Evaluate test results.
- Identifying The Primary And Secondary Phasor Polarities Of Transformers Polarity testing identifies the transformer primary and secondary phasor polarities. It is a must for poly phase connections.
- Transformer Turn Ratio Testing [PDF] A direct relationship exists between the number of turns and the voltage ratio of the primary to the secondary.
- Current Transformer Basics: Understanding Ratio, Polarity, and Class The polarity of a current transformer is determined by the direction of the coils are wound around the core of the CT (clockwise or counter clockwise) and by the way the secondary leads are brought out of the transformer case.
- Preliminary Checks for the Hand Crank TTR Learn how to check for mechanical wear or electrical failures in the field that may cause your turns ratio test set to be inaccurate or inoperative.
- Power-factor/dissipation-factor testing - Perform, interpret, and evaluate standard insulation power-factor/dissipation-factor tests on electrical power equipment, including transformers, breakers, cables, bushings, rotating equipment, and insulating liquids.
- Application guide for power factor testing of power & distribution transformers [PDF] Power factor testing is an effective method to detect and help isolate conditions such as moisture, carbonization, contamination in bushings, windings and liquid insulation. In addition to power factor testing, transformer excitation current measurements will help detect winding and core problems.
- Power Factor Testing Dry-Type Transformers The additional costs associated with performing insulation power factor testing on these smaller units are difficult to justify. However, larger dry-type transformers — especially ones that provide critical power — should be given a power factor test to ensure continued serviceability.
- Analyzing Power Factor Test Results Why the common approach can lead to poor, resultant decisions and ought to be rethough.
- Application Guide for Power Factor Testing of Circuit Breakers [PDF] Power Factor testing of Oil, Air-Blast, SF6, Vacuum, and Air Magnetic Circuit Breakers, including Oil Circuit Reclosers.
- Tan Delta Cable Testing [PDF] Tan Delta, also called Loss Angle or Dissipation Factor testing, is a diagnostic method of testing cables to determine the quality of the cable insulation.
- Application guide for power factor testing of bushings [PDF] The power-factor test is the most effective known field test procedure for the early detection of bushing contamination and deterioration. This test also provides measurement of ac test current which is directly proportional to bushing capacitance.
- Power-Factor Testing of Stator Winding Insulation [PDF] Power-factor testing of rotating machinery is another valuable test technique providing information about the integrity of the insulation system.
- The Value of Power Factor Testing [PDF] Insulation power factor tests are used to measure dielectric losses, which relate the wetness, dryness or deterioration of transformer insulation. Both factory and field testing are performed to verify the insulation integrity of substation transformers.
- Dissipation Factor, Power Factor, and Relative Permittivity of Insulating Oil [PDF] The power factor of insulating oil equals the cosine of the phase angle between an AC voltage applied to oil and the resulting current. Power factor indicates the dielectric loss of oil and, thus, its dielectric heating. The power factor test is widely used as an acceptance and preventive maintenance test for insulating oil.
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