What is the proper UL rating to use on electrically energized equipment?

The proper UL rating to use on electrically energized equipment is C. This designation indicates that the extinguisher is suitable for fires involving live electrical equipment, which typically includes machinery, appliances, and electronics. The UL rating system helps ensure that the chosen extinguisher is effective and safe for use in situations where electrical hazards are present.

Using an extinguisher with the appropriate rating is crucial, as certain types of extinguishing agents can conduct electricity and pose a risk of shock or further complications in the event of an electrical fire. Thus, the classification of C specifically designates compatibility with electrical equipment, allowing for safe application without the risk of electrocution or damaging the equipment.