Electrical Engineering Investigations

Investigating and pinpointing the causes of electrical failures is a highly specialized discipline. The Polaris engineering team has extensive experience in assessing electrically induced fires, electrical accidents and electrical failures, regardless of the size or source. We utilize the latest technology such as Infrared imaging to identify electrical wiring within walls to pinpoint the causes and sources of the issues.

Feasibility Study

Electrical Bus Duct Blast Failure

Polaris was engaged to evaluate the damage to the 2000A bus duct at a multi-story commercial office structure in Texas.  The electrical service at the structure consisted of 2000A, 277/480V distributed through a 2000A vertical aluminum ‘Cutler Hammer’ bus duct.  Polaris observed that the bus duct was damaged. A hole consistent with heating of the duct wall and smoke signature were observed around the bus duct wall. Shrapnel debris was observed at the panels in the vicinity of the failed bus duct. The failed bus duct was opened for Polaris’s examination. Heat damaged insulation and four heat damaged bars were observed inside the bus duct. Based on the observations, Polaris determined that the damage at the bus duct at the structure was related to an arc blast which occurred within one section of the 2000A bus duct.

An arc blast is one of the effects of an arc flash.  When a short circuit occurs, it can often cause arc blast, a type of highly dangerous electrical explosion.  Its explosive force can turn metal objects into high-speed shrapnel.

Polaris’s scope of work also included determining the cause of the arc blast.  Polaris’s electrical engineering experts did not observe any evidence of human error due to recent maintenance or otherwise. Further, no evidence of buildup of conductive dust, dirt/foreign debris, moisture or other conductive liquids, significant corrosion of electrical components, or animal contact (e.g., rodents, roach, spider) which would have caused or contributed to the failure of the bus duct.  Polaris obtained and reviewed lightning data on and around the date of failure, which indicated that no lightning strikes occurred.

In the absence of any other external event, Polaris’s electrical engineering experts determined that the arc blast at the bus duct was caused by age-related degradation.  The age of the equipment was reported to be approximately 30 years and aged/weathered conditions were noted by Polaris.  Polaris also provided repair recommendations which included removal and replacement of the bus duct. 

Hole in the bus duct

Damaged insulation in the bus duct

Heat damage to bars

“With so many options for experts, I know I can count on Polaris for an accurate and impartial report. Plus, their service is timely and within budget.”

- Harry H.

General Property Adjuster, Insurance Carrier

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* Polaris Forensics, Inc. provides services only in states in which it and its experts are authorized to perform such services by the state licensing boards.