Failure analyses are a required part of the arsenal of tools utilized in continuous improvement for highly regulated industries, such as nuclear power generation. Situations adverse to quality demand a root cause analysis. Without a failure analysis, they may not be considered within these continuous improvement guidelines. Finding out why a component failed is the first step toward positive change in operations, from supporting daily production to improved procurement practices and overall safety.

Exelon PowerLabs’ engineers and technicians have extensive experience as well as decades of failure analysis service data to accurately determine the root cause of a component failure. The quality of the root cause determination is key to driving the right corrective action to prevent recurrence. Correctly diagnosing root cause to inform meaningful corrective action can include the following advantages:

Safety – Safety is among the highest in priority when it comes to any business operation. After a failure is assessed, this allows the business to take corrective action. When the failure is identified, businesses can eliminate the safety concern in the facility, which will allow safer working conditions for employees.

Reducing costs – When a failure is identified and evaluated properly, this can help reduce costs since there will be less maintenance on the component when the customer knows what has contributed to the failure.

Equipment reliability – If a component is found to have failed due to a manufacturing defect or has been improperly mishandled, it can cause downtime. To better manage equipment reliability, it’s important to correct the action by training employees to use the component correctly or replace and test the part before installation since they will know what to look for when testing.

Improved supply chain—It revises procurement specifications to require manufacturers to meet higher standards for parts with a history of failure. Alternatively, explore new suppliers for high failure component applications, or use failure analyses to inform continuous improvement dialogue with manufacturers.

High quality failure analysis services can be an important aspect of continuously improving operations. Exelon PowerLabs receives failure analysis service requests almost daily, as other business operations want to learn and grow from their component failures.

Turning Up the Heat in Failure Analysis

This past year, a 300-pound transformer overheated at a facility. The expected lifespan for this transformer was 20 years, yet it failed shortly after eight years. The transformer was then removed from service and sent to Exelon PowerLabs for a failure analysis for further investigation. A visual inspection was first performed which showed evidence that the irregular heat source started in the center coil and charred the top of the coil.

After the transformer was observed, it was then disassembled. After taking apart the component, it was found that a section of copper was melted near the coil which indicated a significant amount of heat. The melting point for copper is extremely high at a temperature of 1,984°F, indicating an arc flash must have occurred. If this was the case, this means that there was an electrical problem that created the arc.

Determining the Cause

The engineers found that the failure was a manufacturing issue based on how the transformer was built. As they examined further, it was found that the inner core of the transformer showed deformed warped plates. The core function was supposed to concentrate the magnetic flux. When the manufacturer built the transformer, some action applied to the metal plates disturbed the magnetic flux flow.

If the component is well insulated, an electrical arc cannot break through the dielectric. With this component, reduced dielectric spacing was identified. The magnetic flux was impeded generating heat, and the coil to core distance was slightly reduced, which caused the arc to jump from the copper core to the magnetic core causing an arc event. The arcing was located inside the coil closest to the transformer’s core. The coil likely glowed from the heat and broke down which provided the path for arcing from the coil to the core.

Knowledge is Power

As findings are noted in the failure analysis final report, the customer can use this knowledge at their discretion. Returning the component to the vendor for failure analysis will not always provide an unbiased root cause analysis. Exelon PowerLabs provides an experienced, objective third party look at your component failure issues.  While the goal of failure analysis is to help determine the accurate root cause of why a component failed, it is just as important to use that accurate assessment to implement corrective actions, so your operation does not experience a repeat failure affecting downtime and profitability.

This transformer failed due to a manufacturing defect in the way it was assembled and built. The customer could then reach out to the manufacturer with these findings, and work on getting these surmountable issues resolved. Moreover, the manufacturer can then utilize insights from the failure analysis to implement changes, possibly even a redesign, and improve component performance and retain customer loyalty.

Taking Proactive Action

Failure analysis reports are essential to take the extra steps necessary to protect daily operations, profitability and most importantly, employee safety. A detailed report can lead to better informed decisions to ensure this failure mode does not happen again. Taking the right corrective action is critical for thriving in a safer work environment.