Which type of extinguisher is most effective for putting out a fire in an electrical motor?

A CO2 extinguisher is considered the most effective for extinguishing a fire in an electrical motor due to its unique properties. Carbon dioxide is a non-conductive agent, meaning it does not conduct electricity, making it safe to use on electrical fires. When applied, CO2 displaces oxygen around the fire, effectively smothering it and bringing down the temperature. This approach not only effectively extinguishes the flames but also minimizes the risk of re-ignition that can occur with other extinguishing agents.

In contrast, while water extinguishers can be effective for many types of fires, they are not safe for use on electrical fires because water is a conductor of electricity and can pose serious risk to the user. Dry chemical extinguishers can also be effective on electrical fires, but they may not be as safe to use in all situations compared to CO2. Foam extinguishers are designed primarily for flammable liquid fires and are similarly unsafe for electrical fires due to potential conductivity. Hence, CO2 extinguishers are the preferred choice in this context.