3
ESL 500 Series
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.
Removing the Detector
To remove the detector from the mounting base, grasp the
detector and turn it counterclockwise approximately 15 degrees.
The detector should snap off of the mounting base.
To remove the detector from the mounting base when the
detector/base lock is used, insert a small screwdriver into the
locking tab slot on the side of the base and press in while simulta-
neously turning the detector counterclockwise 15 degrees. See
Figure 8.
1
ON
2
1
ON
2
Models with gaskets:
521CRXT, 528CRXT, 541C, 541CXT,
541AXT, 548C, 548CXT, 548 AXT
Models without gaskets:
511C, 511AFT, 518C, 518AFT, 521B,
521BXT, 528B, 528BXT
Figure 5. Detector installation
ESL
204-12/24V
Power
Supervision
Relay
541/548 Series 4-wire wiring diagram
Figure 6. Wiring diagrams
First
Detector
Last
Detector
EOL Resistor
Model 541CXT/548CXT
Model 541C/548C
541AXT, 548AXT
Power
Listed Alarm Control
Note: The 541/548 Series are not
CleanMe compatible
Initiating
Circuit
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511/518/521/528 Series 2-wire wiring diagram
2-wire
initiating
circuit
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Listed Alarm Control
First
Detector
Last
Detector
EOL
Device
NO COM NC
Model 521CRXT/528CRXT
Model 511C/518C
511AFT/518AFT
521B/528B
521BXT/528BXT
Note: The 521/528 Series are polarity sensitive.
Note: The 511/518 Series are not CleanMe
compatible.
Warning: The system may not operate if the
detector is not connected to the control unit
initiating device circuit as specified in the
detector or control unit literature.
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