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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....


Radiator Fin(s) Leak Repair

Radiator fins are notorious for leaking at various locations. One of which is where the fins are attached (welded) to the horizontal bottom-run header. Measurements are taken so a weir box can be installed to cover the fin(s) that are leaking. It is preferred the weir box will cover above the...

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


transformer repair

Radiator Fin(s) Leak Repair

Radiator fins are notorious for leaking at various locations. One of which is where the fins are attached (welded) to the horizontal bottom-run header. Measurements are taken so a weir box can be installed to cover the fin(s) that are leaking. It is preferred the weir box will cover above the...

Insulation Resistance Test

Insulation Resistance (IR) test, often called Megger test, is more than 100 years old and assumed to be a very straightforward test. During my inspection and testing work in the past 15 years in Canada, US, and internationally, I have seen different practices of performing and interpretation of IR...

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...

hydrocarbon gas emission

Advancements in Dissolved Gas Analysis: Data Quality

IntroductionThere is more to DGA interpretation than comparing the latest gas concentrations to limits in a table or plotting them in a triangle or pentagon to identify the apparent fault type. We have found that the whole DGA history of a transformer must be considered when interpreting its most...


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