What must cartridge fuses used for branch circuit protection be marked with?

• A. Ampere rating, voltage rating, and interrupting data
• B. Current rating, power rating, and interrupting data
• C. Only ampere rating and voltage rating
• D. Voltage rating and type of fuse

Answer: (A)

Cartridge fuses used for branch circuit protection must be marked with an ampere rating, voltage rating, and interrupting data to ensure safe and effective operation within electrical systems. The ampere rating indicates the maximum amount of current the fuse can handle before blowing, which is crucial for preventing overcurrent situations that could potentially cause fire hazards or damage to electrical components.

The voltage rating is equally important because it signifies the maximum voltage the fuse can operate at safely. If the voltage exceeds this rating, the fuse may not function correctly and could lead to a dangerous situation.

Finally, the interrupting data indicates the fuse's ability to safely interrupt fault currents. This information is vital for ensuring that the fuse can handle short circuits or overloads without causing an explosion or fire. Together, these markings provide essential information for users and electricians in selecting and using fuses effectively in branch circuits, ensuring compliance with safety standards and maintaining the integrity of electrical systems.