What differentiates 'manual' fire alarm systems from 'automatic' ones in NFPA 72?

The distinction between manual and automatic fire alarm systems is fundamentally based on the requirement for human intervention. Manual fire alarm systems do not activate the alarm until a person physically operates a manual pull station or similar device. This means that individuals in the environment must notice the fire or potential danger and take action to alert others and initiate the alarm.

On the other hand, automatic fire alarm systems are designed to detect smoke, heat, or flames and activate the alarm system automatically without human involvement. These systems utilize sensors and detectors that continuously monitor the environment and respond independently to fire conditions, thereby facilitating a quicker response that can be crucial in fire emergencies.

This operational difference highlights the key functionality of each system and underscores the importance of manual systems in empowering individuals to take action, while automatic systems enhance safety by reducing reliance on human response.