What are the NAC circuit specifications for the NFS-320, and how does the shared 6-amp power supply limit total NAC loading?

The NFS-320 features four built-in Notification Appliance Circuits (NACs) that can be configured for Class A (Style Z) or Class B (Style Y) operation (Page 25) [1].

Each circuit is rated for a maximum of 1.5 A (Page 8) [1].

Total NAC loading is governed by shared power limits where the four NACs and the TB10 DC power output share a maximum of 6.0 A in alarm and 3.0 A in standby (Page 25) [1].

While the power supply provides a total of 7.4 A in alarm, this must be shared across all internal circuitry and external 24V power provisions (Page 59) [1].

For supervision, these circuits require 2.2K ohm, 1/2 watt end-of-line resistors (Page 59) [1].

The system also supports selectable strobe synchronization for System Sensor, Wheelock, or Gentex appliances [1].