High-Voltage Transformer Fires

HCT has worked with FDNY and conEdison in New York City as a result of F-500 Encapsulator Agent’s outstanding performance extinguishing a transformer fire.

FDNY first deployed 5,000 pounds of dry powder followed by a foam application and could not extinguish the transformer fire. After the dry powder and foam failed, FDNY HazMat Company 1, users of F-500 since 2002 for 
flammable liquid spill control,
 suggested the use of F-500 for
 the transformer fire. The F-500
 Encapsulator Agent was ap
plied and extinguished the fire 
within 2 minutes.

These results
 are not surprising to those who 
understand the difference between the fire suppression me
chanics of foam vs. an Encapsulator Agent. Based on this 
incident, HCT worked in conjunction with both FDNY and
 conEdison to perform some high-voltage current leakage tests. F-500 Encapsulator Agent, AFFF and AR-AFFF 3% solutions were applied to 50,000 volts and the leakage current back to the nozzle was recorded. Since the AFFF and AR-AFFF have bubble to bubble contact, a current leakage pathway back to the nozzle occurs resulting in currents greater than acceptable (e.g. potential injury or death). On the other hand, the current leakage from F-500 Encapsulator Agent solution, which is not a foam, was well within the acceptable range. Based on this, phase 2 testing with 3% F-500 Encapsulator Agent solution on 345,000 volts was conducted with the same results. The current leakage feedback to the nozzle was well within acceptable limits.

Based on F-500 Encapsulator Agent’s three-dimensional, flammable liquid firefighting capabilities and the current leakage testing conducted by FDNY and conEdison, a Standard Operating Guideline (SOG) for the use of F-500 Encapsulator Agent on energized high- voltage transformers was written and adopted. Transformers are not only located at power plants, but also in every community in the United States. With these new SOGs outlining procedures for early attack of energized transformers, F-500 Encapsulator Agent will be the product of choice for power plants as well as municipal fire departments throughout the United States and the world.

®conEdison is a registered trademark of Consolidated Edison, Inc., New York City, NY