The NFS2-640 features four onboard Notification Appliance Circuits (NACs) rated at 1.5 A each (Page 2) [1].
These 24 VDC circuits are supervised and power-limited, supporting both Class B (Style Y) and Class A (Style Z) configurations using a 2.2K ohm end-of-line resistor (Page 37) [1].
| Specification | Rating |
|---|---|
| Number of Circuits | 4 |
| Current per Circuit | 1.5 A |
| Total Shared Alarm Power | 6.0 A |
| Voltage | 24 VDC |
| EOL Resistor | 2.2K ohm, 1/2 watt |
An external NAC booster panel is required if the total current demand of all notification appliances exceeds the 6.0 A shared power limit, or if any single circuit's load exceeds 1.5 A (Page 37) [1].
Note that the 6.0 A limit is shared between the four NACs and all other internal panel circuits and modules during an alarm condition (Page 2) [1].
