For those of you who haven’t seen Amerex’s Tech Tip #14, it is attached for your review. While this Tech Tip was written for the Model 260/262 Wet Chemical extinguisher, the same UL test and principle applies to the Model 272. The Model 272 was subjected to and passed the same “Class C” listing test by UL. In fact, using distilled water makes it slightly less conductive than the Model 260/262 Wet Chemical charge.
Recently, some people have voiced concern over the “pooling” of water from the Model 272 discharge. They feel this will create an electrical shock hazard that is not represented by the UL electrical conductivity test. We would like you to consider the following:
For nearly 50 years, fire hose nozzles have been listed by UL for use on electrical fires, without
any known injuries from electrical shock
Sprinkler systems have been installed in countless high-rise buildings without benefit of
shutting off all electricity to the building during a discharge – again without any known injuries
due to electrical shock.
NFPA 10 paragraph 3-5 has the following note: “Electrical equipment should be de-energized
as soon as possible to prevent re-ignition.”
Any piece of electrical equipment that has been involved in a fire has had its safety features
compromised (insulation may be burned, ground connections lost, etc.) and therefore may
present a hazard regardless of what type of agent is used.
In tests conducted by Amerex, using a toaster, an electric fan and an electric motor, we were
unable to create an electrical shock hazard in the “pool”. Either the circuit tripped immediately
de-energizing the equipment, or there was not sufficient voltage and current in the pool to detect.
Amerex is more than confident in the safety of these extinguishers. Based upon the required UL testing and the additional tests that we have performed, the Model 272 is the only water based extinguisher on the market that is safe to use around live electrical equipment.
Let us know about your comments and suggestions.