Which type of fire extinguisher is typically used on a live electrical fire?

The use of a carbon dioxide (CO2) fire extinguisher on a live electrical fire is due to its safe and effective nature in handling such situations. Carbon dioxide extinguishers operate by displacing oxygen from the vicinity of the fire and cooling the flames through the release of the gas. This is particularly advantageous for electrical fires, as CO2 does not conduct electricity, making it safe to use on live electrical equipment without the risk of electric shock.

In contrast, pressurized water extinguishers are inappropriate for electrical fires because water is a conductor of electricity and using it could lead to severe safety hazards, including electrocution. Dry chemical extinguishers can be effective as well, but they may leave a residue that could damage sensitive electronics. Aqueous film forming foam (AFFF) extinguishers are primarily designed for flammable liquid fires, and while they can be used in some scenarios involving electrical equipment, they are not the preferred choice for live electrical fires due to their potential conductivity and inefficiency in the situation. Therefore, the carbon dioxide extinguisher is the most suitable and safest option for electrical fires.