What is Tan Delta Testing?
Tan Delta testing is a quick and non-invasive method to evaluate the health of electrical insulation. It measures the energy loss (dielectric loss) in the insulation material. When Tan Delta values are higher, it indicates that the insulation is losing more energy, which usually means it is aging or damaged. The test is useful for predicting how much longer the equipment will last and for deciding whether repairs or replacements are needed.
What is a Good Tan Delta Value?
A Tan Delta value below 0.5% (or 0.005) is considered good for insulation at 20°C. As insulation ages, Tan Delta values may naturally rise. However, an increase of more than 0.1% per year (0.001 per year) is not acceptable. If only the Tan Delta value increases (without a change in capacitance), it means the insulation is likely deteriorating. If both Tan Delta and capacitance increase, this could indicate moisture is entering the insulation.
How to Interpret Tan Delta Results?
To interpret the results, compare the Tan Delta values at the start and end of the test. The difference, called "delta," should be less than 0.005 for a new transformer. For older equipment, it should be less than 0.001. A large increase in Tan Delta indicates potential insulation problems.
How is Tan Delta Calculated?
In a typical electrical system, insulation acts like a capacitor. The current through it has two parts:
Capacitive Current (IC): This leads the voltage by 90 degrees.
Resistive Current (IR): This is due to impurities in the insulation.
Tan Delta is calculated by dividing the resistive current (IR) by the capacitive current (IC). A lower Tan Delta value means better insulation and lower energy losses.
Tan Delta is calculated by dividing the resistive current (IR) by the capacitive current (IC). It is expressed as:
Tan δ = IR / IC
In this formula, IR represents the resistive current due to impurities in the insulation, while IC is the capacitive current. A higher Tan Delta indicates more energy loss, signaling insulation degradation.
What Does a High Tan Delta Mean?
A high Tan Delta value means the insulation is losing more energy, which can shorten the lifespan of the equipment. It often signals that the insulation is degrading due to aging, contamination, or moisture. A negative Tan Delta value is usually an error and indicates a problem with the test setup.
About Rui Du Mechanical and Electrical (Shanghai) Co., Ltd.
Rui Du Mechanical and Electrical (Shanghai) Co., Ltd. is a trusted provider of electrical testing equipment and services. The company specializes in Tan Delta testing and other diagnostic tools to help industries maintain the quality and reliability of their electrical equipment.
For more information about Tan Delta testing and other services, visit www.wrindu.com.
About Wrindu RD6000A Transformer Tan Delta Tester
The RD6000A Transformer Tan Delta Tester from WRINDU offers an advanced solution for tan delta testing, using frequency conversion power supply and single-chip microcomputer technology. It ensures high accuracy, fast testing, and fully automated operation. With a 10kV output and noise suppression, it performs reliably even in high-interference environments, making it ideal for precise transformer testing in challenging field conditions.
Media Contact
Company Name: Rui Du Mechanical and Electrical (Shanghai) Co., Ltd.
Email: Send Email
Phone: 13661908522
Address:No.500 Jianyun Road, Pudong New Area
City: Shanghai
Country: China
Website: https://www.wrindu.com/