Electricity Forum Intelligent Power Today Magazine Arc Flash Clothing

Electrical Transformers


Grounding Transformers Explained

By R. W. Hurst, Editor Grounding transformers are used to provide a path to ground for unbalanced load current and for fault currents on systems where a suitable ground is otherwise not available. Grounding transformers are normally constructed with one of the two configurations: Zig-Zag (Zn) with...

Transformer Diagnostic Testing

Transformer diagnostic testing: standards to diagnose equipment with Sweep Frequency Response analysis BY VOLNEY NARANJO, Megger Sweep Frequency Response Analysis (SFRA) has become a powerful tool in advanced power transformer assessments and probably one of the main and first tools used to...

A New Approach to High Voltage Insulation System Testing

Speed is the driving force of successful fault prevention. Early detection of insulation deterioration is key for avoiding asset failure, associated unplanned outages, and physical damage to infrastructure. The traditional testing approaches most teams rely on inhibit quick diagnosis of insulation...

Electrical Transformers

Transformer testing and failure analysis

Power Transformer Failures

Electric utilities maximize utilization of their assets, while maintaining reliability. Power transformers are typically reliable, but have been known to fail suddenly and/or prematurely. Transformer failures are both costly and can leave customers dissatisfied, harming the reputation of a utility. Common events or conditions that can lead to a transformer failure include lightning or switching impulses, sustained overvoltage, short circuits on the electric system, overloading, overheating, dielectric breakdown of the insulating oil due...

Related Articles


A New Approach to High Voltage Insulation System Testing

Speed is the driving force of successful fault prevention. Early detection of insulation deterioration is key for avoiding asset failure, associated unplanned outages, and physical damage to infrastructure. The traditional testing approaches most teams rely on inhibit quick diagnosis of insulation...

Prevent Transformer Shutdown

Power transformers seldom shutdown; however, if a shutdown occurs, the effects would be immediate and devastating to utility operations. According to “An Analysis of Transformer Failures” by William H. Bartley, P.E., on behalf of the Hartford Steam Boiler Inspection and Insurance Company, the...


Page 1 of 12