1. Fault SituationIn September 2023, as a front - line fault maintenance worker, I detected abnormal voltage on the 10kV Section I bus of a substation during monitoring duty and informed the operation and maintenance team. The monitoring system showed: U0 = 0 kV, Ua = 6.06 kV, Ub = 5.93 kV, Uc = 6.05 kV, Uab = 10.05 kV, Ubc = 5.94 kVMy team and I rushed to the site. We suspected the secondary air circuit breaker of the 10kV Section I bus voltage transformer was closed and found the U - phase fus

By Felix, 15 Years in the Electrical IndustryHi everyone, I'm Felix, and I've been working in the electrical industry for 15 years.From early involvement in traditional substation commissioning and maintenance to now managing electrical system operations for multiple photovoltaic and wind power projects, one of the most frequently encountered devices I deal with is the Electromagnetic Voltage Transformer (PT).The other day, a shift operator at a new energy plant asked me:“We have an electr

By Echo, 12 Years in the Electrical IndustryHi everyone, I'm Echo, and I've been working in the electrical industry for 12 years.From my early days doing commissioning and maintenance in distribution rooms, to later participating in electrical system design and equipment selection for large-scale projects, I’ve witnessed how dry-type transformers have evolved from traditional tools into smarter, greener devices.Recently, a new colleague asked me:“What’s the current state of dry

By James, 10 Years of Electrical Equipment Maintenance ExperienceHi everyone, I’m James, and I’ve been working in electrical equipment fault repair for 10 years.Over the past decade, I’ve worked in factories, substations, and distribution rooms of all sizes, involved in the installation, commissioning, maintenance, and troubleshooting of dry-type transformers. Dry-type transformers are among the most common electrical devices we deal with on a daily basis.Today, a new colleague

Hi everyone, I’m Felix, and I’ve been working in electrical equipment fault repair for 15 years.Over these years, I’ve traveled across factories, substations, and distribution rooms all over the country, troubleshooting and repairing all kinds of electrical equipment. Dry-type transformers are among the most common devices we deal with.Today, a friend asked me:“What does it mean when the low-voltage side of a dry-type transformer has low insulation resistance?”Great

1 Pre - commissioning InspectionAs a front - line tester, before formally commissioning a dry - type transformer, I need to carry out a comprehensive and systematic inspection. First, I conduct a visual inspection of the transformer body and its accessories, carefully checking for mechanical damage or deformation. Then, I check whether the leads of the high - and low - voltage windings are firmly connected and whether the bolt tightening torque meets the standard requirements (usually 40 - 60N&m