| No. |
Client Type |
Determine the Origin of a Home Fire |
Year |
|---|---|---|---|
| 6 | Insurance
Firm and Attorney Firm
|
Project/Case
Basics: A bedridden gentleman was at home in a rented
hospital bed. The bed also had a rented pulsating air mattress
for the aversion of bedsores. During the night, the wife who
slept in another room heard her husband call out because his bed was
on fire. She was unable to extinguish the flames and he perished
in the fire. Subsequent investigation by the State Fire Marshall
indicated the fire started at the foot of the bed, centered over the
wall outlet where the bed was plugged in.
Consulting Issues: The rental bed was plugged into the 2-prong outlet at the foot of the bed. The bed was a 3-prong device and the ground pin had been broken off so the plug would work. Examination by fire investigation experts also indicated the source of the fire was probably the power cord assembly of the rental bed. Portions of the bed power cord appeared to be melted by their direct visual examination. BME Work: An objective and very detailed review of the fire evidence that had been collected from the home was accomplished. Inconsistencies with the fire starting at the foot of the bed were found in the state of the power cords from the rental bed, rental pulsating air mattress motor, an air filter, and the home electronics - TV, VCR, and tape recorder. The home electronics power cords showed signs of copper beading caused by arcing that makes the copper melt. This phenomenon means there was AC voltage applied to the power cord during the fire but does not necessarily indicate the source of the fire. If the fire starts elsewhere, insulation burning away from the power cord may let the conductors short and arc. Outcome: Using Scanning Electron Microscopy (SEM) examination of power cords that were burned in the laboratory with and without AC power applied, a set of copper melting patterns were developed. Also, shorted power cords used in attempts to cause ignition were examined. When carefully compared to SEM's of the actual equipment wiring, it was found that there was no power applied to the bed power cord when it was in the flames. Also, it was demonstrated that the lack of the ground pin was not the cause of the fire. Overall analysis demonstrated the fire had started by the television, the power cords arced and a circuit breaker opened. This circuit breaker also controlled the outlet at the foot of the bed where the bed was plugged in. The fire then spread from the television area to drapes over the bed. Drapes fell down while on fire at the foot of the bed creating a secondary "V" pattern. The fire was very hot at the foot of the bed but the power cord to the bed did not arc because there was no applied AC voltage by the time the fire reached that area. The primary "V" pattern was very large and centered over the television. Once the report was submitted and a deposition taken, the case settled. Relevance: In this instance, the home care rental company was in a difficult position because the ground pin was cut from the bed. While this is adverse for electrical safety, it did not, in this instance cause the fire. However, it is important that home wiring be considered for both electrical and fire safety when relatively high draw medical equipment is installed. Also, the improper wiring installation caused the rental company to have to vigorously defend itself in this matter. |
1998 |
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