How far must a flammable-liquid or oil-filled transformer be mounted from a combustible building surface?

The correct answer to how far a flammable-liquid or oil-filled transformer must be mounted from a combustible building surface is 8 feet. This requirement is in accordance with safety regulations aimed at minimizing the risk of fire hazards associated with such equipment.

Transformers that contain flammable liquids or oils pose a significant fire risk, as these substances can ignite and lead to dangerous situations. By maintaining an 8-foot distance from combustible materials, the potential for flames to spread to nearby structures is significantly reduced. This safe distance helps to protect both the transformer and the surrounding area from fire-related incidents.

Other options suggest shorter distances that do not align with safety codes for fire prevention, which are designed to ensure adequate space in case of an emergency. Regulatory guidelines are established based on research and best practices in fire safety, and the 8-foot requirement is grounded in that rationale to provide an effective buffer zone against possible ignition sources.