PREALM: NFS2-640 Trouble Code | Fire Alarm Resource Center

What This Code Means

A Pre-Alarm Warning indicates that a smoke detector has reached a programmed threshold (either Alert or Action level) that is below the actual alarm threshold, providing an early warning of potential fire conditions.

Common Causes

1Incipient or potential fire conditions
2Dust or dirt accumulation in the detector chamber
3Transient noise or electrical interference
4Environmental factors such as steam or aerosols
5High sensitivity settings (Self-Optimizing Pre-Alarm)

Resolution Steps

Identify the device location from the LCD display and investigate the area for signs of smoke or fire. Check the real-time smoke level percentage shown on the LCD. If the condition is an 'Alert' (non-latching), it will clear automatically when smoke levels drop. If it is an 'Action' (latching), press the RESET key after the condition has been cleared. Press ACKNOWLEDGE to silence the panel sounder.

Manual References(1)

1notifierNFS2-640Datasheet2017Open

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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