Understanding The Led; Cleaning The Detector; Maintaining The Detector - GE 521NB Installation Instructions Manual

Understanding the LED

The LED on the detector indicates the status of the detector as
follows:
Flashing every 9 seconds = Normal operation.
On = Detects smoke, sending an alarm.
Off or flashing once every 1.5 seconds = Trouble or maintenance
is required. Test the detector. See Testing the Detector Sensitivity.
Testing the Detector Sensitivity
The detector provides a sensitivity test that allows you to check
the detector sensitivity using a test magnet and the LED indicator
on the detector as follows:
1. Hold the test magnet up to the raised TEST letters on the
top of the detector for 2 seconds. See Figure 6. Once the test
starts, the alarm LED flashes one to nine times.
2. Count the number of times the LED flashes and use the
following table to determine the status of the detector
sensitivity and what action to take, if any.
Flashes Indications
1 Unserviceable
hardware fault
detected.
2-3 Detector is
becoming
insensitive.
4-7 Detector is within
normal sensitivity
range.
8-9 Detector is
becoming too
sensitive.
After the test:
If the sensitivity is within limits and all other tests pass, the
detector goes into alarm and must be reset from the control panel.
If the sensitivity is not within limits or an unserviceable
hardware fault has been detected, the detector LED flashes
every 1.5 seconds until the detector is serviced.

Cleaning the Detector

Clean the detector cover with a dry or damp (water) cloth as
needed to keep it free from dust and dirt.
When necessary, clean the detector interior and replace the optical
chamber as follows:
1. Disconnect the alarm notification appliances, service release
devices and extinguishing systems.
2. Slide a flat-blade screwdriver into the slot on the detector cap
and gently push the handle down to pry the cap up and off.
See Figure 8.
3. Press in on the sides of the optical chamber and pull it up and
away from the detector and discard. See Figure 9.
4. Use a vacuum to remove dust and dirt from the optical
chamber base.
5. Line the new optical chamber up with the optical chamber
base and snap it down into place.
6. Replace the detector cap as follows:
-Line the tabs on the cap with the slots on the detector.
-Insert the cap into the smoke detector and turn clockwise
approximately 15 degrees. It should snap firmly into place.
4
Action
Reset unit and rerun sensitivity
test. If the error persists, replace
the unit.
Clean the unit per instructions.
Reset unit and rerun sensitivity
test. If the error persists, replace
the unit.
N/A
Verify that the smoke chamber
is snapped down securely. Clean
the unit.
7. Test the detector sensitivity (See Testing the Detector
Sensitivity).
8. Reconnect all alarm notification appliances, service release
devices and extinguishing systems.
Important: The control panel alarm and all auxiliary
functions should be verified for a complete test of the system.
Figure 6. Testing the detector
Figure 7. Unlocking the detector
Figure 8. Removing the detector cap
Figure 9. Removing the optical chamber

Maintaining the Detector

These smoke detectors are designed for easy field service and
maintenance. When installed and used properly, they require
minimal maintenance.
The smoke detector should be tested monthly. See Testing the
Detector Sensitivity and Smoke Testing the Detector.
Optical chamber
base
Optical chamber
Detector cap
ESL 500N Series