What is the minimum percentage for overcurrent protection for batteries in a fire alarm system?

The correct answer is based on industry standards and guidelines that dictate how to ensure safety and reliability in fire alarm systems. For overcurrent protection of batteries in such systems, a minimum of 150% is required.

This 150% threshold is established to accommodate potential inrush currents and transient conditions that may occur when the system is activated. By providing overcurrent protection at this level, it helps to mitigate the risk of component failure and ensures that the system can withstand operational demands without compromising the safety features of the fire alarm system.

Higher percentages, such as 200% or 250%, may provide extra protection but are not considered necessary for standard applications, leading to potential waste in terms of cost and equipment sizing. Setting the overcurrent protection at a minimum of 150% balances safety and efficiency, complying with recommended practices in the field.