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Transformer Testing & Maintenance


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....

Zensol new instrument for OLTC testing

According to CIGRE A2.34, the dynamic resistance measurement or DRM (OFFLINE) is a test that offers diagnostics for several diverter or selector switch malfunctions such as: contact problems, broken springs, broken transition resistors, poor contact pressure, inadequate transition time, momentary...

Power Utility Replaces Aging Transformers with Customized, Drop-in Units

As aging transformers at generation facilities near end-of-life cycles, a number of potentially dangerous events can come into play when it comes to aging transformers – in addition to untimely power outages and costly repairs. Because many transformers are exposed to dust and high operating...

Transformer Testing & Maintenance

Normalized Energy Intensity chart

Advancements in Dissolved Gas Analysis: NEI & Gassing Events

One of the most important steps when looking at DGA data is to decide whether the data support the existence of a fault that is actively breaking down the insulation before you try to use a triangle, pentagon, or gas ratio method to identify a fault type. Otherwise, you are diagnosing random measurement noise, not the transformer. Conventional methods assign limits to each of the gases to detect and assess abnormal gas formation. Formerly it...

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...

Harmonic Problems in Power Transformers

Preventing malfunction in power transformers BY ANDY SAGL, Megger Harmonics are another power quality phenomenon that can cause equipment to malfunction. Harmonics are a sinusoidal component of periodic waves that have frequencies that are multiples of the fundamental frequency. Harmonics can cause...


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