Fires involving live electrical equipment such as transformers would be classified as:

Fires involving live electrical equipment, such as transformers, are classified as Class C fires. This classification is specifically designated for fires that involve energized electrical equipment and wiring. The rationale behind this classification is that water and certain other extinguishing agents can create a risk of electrocution if used on live electrical fires.

In a situation involving Class C fires, it is crucial to use extinguishing agents designed for electrical fires, such as carbon dioxide (CO2) or dry chemical extinguishers, to ensure safety and effectively suppress the fire without the risk of conducting electricity. Understanding this classification helps safety professionals determine the appropriate response to electrical fire incidents, ensuring both effective fire suppression and the safety of individuals involved.