TROUBL CONTROL: NFS2-640 Trouble Code | Fire Alarm Resource Center

What This Code Means

A trouble condition occurring on a Notification Appliance Circuit (NAC), indicating an electrical fault such as an open or short circuit on the supervised output.

Common Causes

1Open circuit in NAC wiring
2Short circuit in NAC wiring
3Faulty notification appliance
4Missing or incorrect end-of-line resistor

Resolution Steps

Press the ACKNOWLEDGE/SCROLL DISPLAY key to silence the panel sounder and switch the SYSTEM TROUBLE LED to steady. Check the LCD display for the specific device address and the type of trouble (e.g., OPEN or SHORT). Inspect the wiring and devices at the indicated location and correct the fault. The panel will return to normal operation once the condition is corrected.

Manual References(1)

1notifierNFS2-640Operations2013p. 34Open

Related Codes

INVREPThe device has returned a response to the panel that the panel did not expect.INST ON L1No devices are installed on the system.LO VALThe detector chamber reading is too low, or the detector is not operating properly. In CLIP mode, this may also indicate a failure of the thermistors, CO element, or infra-red element, or a freeze warning.PREALMThe control panel activates a Pre-Alarm Warning when a detector exceeds its programmed Pre-Alarm Alert or Action level, providing an early warning of incipient or potential fire conditions.NETWORK FAIL PORT xCommunication lost between NCM Port x and corresponding node.

Notifier NFS2-640

What This Code Means

Common Causes

Resolution Steps

Manual References(1)

Field Notes

Related Codes

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