220kV PT Dielectric Loss Testing & SF6 Circuit Breaker Moisture Testing at Ezhou Power Plant

Customer: Hubei Energy Group Ezhou Power Plant
Location: Ezhou, Hubei Province, China
Date: July 9, 2026
Service Provider: HKVTEST

HKVTEST provided on-site testing services for a 220kV power system at Hubei Energy Group Ezhou Power Plant, including PT dielectric loss (tan delta) testing and SF6 circuit breaker moisture measurement.

The project aimed to evaluate the insulation condition and operational reliability of high-voltage equipment through professional testing.

• Dielectric Loss (Tan Delta) Tester
• SF6 Gas Moisture Tester

• 220kV Capacitive Potential Transformer (PT/CVT)
• 220kV SF6 Circuit Breaker

Due to the CVT structure, HKVTEST engineers applied the CVT self-excitation method for dielectric loss measurement.

The test was completed by connecting the testing system to the PT secondary side, applying the required test voltage, and measuring the insulation parameters.

Result:
The dielectric loss value was within the specified standard range, indicating that the PT insulation condition was normal.

HKVTEST engineers connected the SF6 gas testing system to the circuit breaker gas outlet and measured the moisture content after the gas flow became stable.

Test Result:

SF6 Moisture Content: 249 ppm

According to the relevant electrical equipment testing standards, the result met the requirement of below 300 ppm for operating SF6 circuit breakers.

Result:
The SF6 circuit breaker insulation condition was qualified and suitable for continued operation.

During the on-site testing, the equipment installation height and limited cable length created connection difficulties.

HKVTEST engineers communicated with the customer's team and arranged suitable working conditions to ensure safe and accurate testing.

The 220kV PT dielectric loss test and SF6 circuit breaker moisture test were successfully completed.

The customer recognized HKVTEST's:

• Professional testing capability
• Reliable equipment performance
• Efficient on-site service
• Technical problem-solving ability

Wuhan Hongzhi Gaocetest Electrical Technology Co., Ltd. (HKVTEST) is a professional manufacturer of electrical testing equipment with more than 16 years of experience.

We provide high voltage testing equipment, transformer testing solutions, insulation testing instruments, cable testing equipment, and customized electrical testing solutions for power utilities, substations, industrial customers, and testing organizations worldwide.

With professional R&D capability, manufacturing experience, and technical support, HKVTEST is committed to helping customers improve power equipment safety and reliability.

📧 Email: fionahuang60@gmail.com
📞 WhatsApp: +86 18071531810
🌐 Website: www.hkvtest.com