Which of the following classes is primarily focused on connections after the overcurrent device?

Class 1 circuits are specifically designed to operate at low voltage and carry a limited current to ensure safety and reliability in their operation. This class of circuits is focused on connections that are made after the overcurrent protection device, which is essential for managing potential overloads and ensuring that the components downstream, such as notification appliances and fire alarm control panels, function within their specified parameters.

By allowing for controlled connections subsequent to the overcurrent device, Class 1 circuits help prevent issues related to excessive current that could lead to circuit failure or fire hazards. This makes Class 1 particularly crucial for various alarm and fire signal applications, as it maintains safety while allowing for the flexibility needed in fire alarm system installations.

In contrast, Classes 2 and 3 circuits have different purposes, focusing on different aspects of utilization or signaling. Class 2 circuits are generally used for signaling between devices without the same constraints as Class 1, while Class 3 circuits can transmit both power and signaling, often with less emphasis on the connections in relation to the overcurrent devices. Understanding these distinctions is vital for professionals working within fire alarm system installations and maintenance.