How many supervisory switches can be connected to a single circuit?

The correct answer is based on the guidelines for supervisory circuits within fire alarm systems. In general, a single circuit is often designed to accommodate a specific number of devices that can communicate effectively without overwhelming the circuit's capacity.

For supervisory switches, the typical standard allows for up to 20 supervisory devices to be connected to a single circuit. This number provides a balance between the ability to monitor multiple points effectively while ensuring that the circuit functions smoothly. Connecting too many supervisory switches can lead to issues such as circuit overload, unreliable communication, or difficulty in identifying the specific source of a problem when one arises.

Understanding this standard is crucial for anyone involved in fire safety and alarm system design, as it ensures that the systems are both compliant with safety regulations and effective in their operation. Consequently, using the correct number of supervisory switches helps maintain reliability and minimizes the risk of system failure during emergencies.