Ground Operations & Servicing
Why should a water-type extinguisher NOT be used on a fire involving energized electrical equipment (Class C)?
Answer
Water is electrically conductive, so it can shock the operator while failing to smother the fire
Water conducts electricity, creating an electrocution hazard for the operator, and it does not smother an electrical fire. The correct agents for Class C are non-conductive ones such as CO2 or a clean agent. The other options invent chemical reactions or trivial reasons that are not the safety basis.
Source: FAA-H-8083-30B, Chapter 1 — 'Fire Protection: Extinguishing Agents'
Not the answer
- Water reacts with copper wiring to release explosive hydrogen gas
- Water is too heavy to be directed onto an electrical panel
- Water leaves a residue that voids the equipment's warranty
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