Arson or Accident?

electrical-engineering-fire

Ronald J. Panunto, PE, CFEI, Electrical Engineering Consultant ::::
Case Synopsis: The state police, with the assistance of the ATF, indicted a female church parishioner for setting a fire in a church located in upstate Pennsylvania. Through investigation, it was found that several of the women who assisted the pastor of the church were vying for his attention, which police believed to be a possible motive
The fire occurred in the pastor’s office, and the state police called in the ATF to check for accelerants. Even though the ATF was unable to confirm the use of accelerants, the state police charged the woman parishioner with intentionally starting the fire.
In examining the evidence retained by the state police, it was found that a space heater was located on a rug underneath of a table where the fire started. The electrical cord to the heater was badly burned and the cord’s conductors had arced.

Result:
The case went to trial where it was demonstrated to the jury that the space heater’s power cord was underneath the space heater and in direct contact with the rug.
It was explained that the heater melted the insulation on the power cord, leading to arcing between the hot and neutral conductors, which in turn ignited nearby combustibles, which included the rug and nearby stacks of paper.
The jury returned a “not guilty” verdict.
Ronald J. Panunto, PE, CFEI, is an Electrical Engineering Consultant with DJS Associates and can be reached via email at experts@forensicDJS.com or via phone at 215-659-2010.

Runaway Treadmill

treadmill-injury

Ronald J. Panunto, PE, CFEI, CVFI, CFC, Electrical Engineering Consultant ::::
Case Synopsis: A middle-aged man, while exercising on his motorized treadmill, was injured when the treadmill suddenly accelerated and threw him up against a wall. He sustained injuries to his head, right shoulder and right arm. His attorney put the manufacturer of the treadmill and the store that sold it on notice.
Expert Analysis: A review of the Consumer Product Safety Commission (CPSC) recalls showed that the incident treadmill had been recalled at least 8 years before our client’s accident, and that there was a second recall just 1 year before the accident. The recall said:
Continue reading “Runaway Treadmill”

Making Machines Safe

Drill Bit

Ronald J. Panunto, P.E., Electrical Engineering Consultant ::::
Case Synopsis: Plaintiff was injured when his core-boring machine struck a rebar and jammed. When the drill bit jammed, the drill carriage broke free, began to turn and slammed into his body. An expert was retained in order to determine if a safety system could be designed whereby the drill motor would stop if the drill bit jammed.
Expert Analysis: An internet search was conducted in order to find a vendor who manufactured speed switches that readily adopted to cylindrical shafts. This was needed in order to sense zero speed on the drill shaft. Upon arrival of the speed switch, a bracket was built to hold the speed sensor attached to the drill carriage. The magnetic split ring speed device was then attached to the drill shaft. Continue reading “Making Machines Safe”