Bosch Building Technologies

    Showing results for 
    Search instead for 
    Did you mean: 

    How to Trouble-shoot a FCP-500 Swinging between Trouble, Alarm & Normal

    Issue - The problem is that the FCP-500 smoke heads are going into trouble then alarm then back to normal all by themselves. The LED blinks green every 8 sec, then double flashes, then flashes red, then back to normal.


    Check to see if there is enough filtered DC current to run all the smokes. Use an alternate power supply or a 12 VDC battery and see if the heads operate normally. Also verify the heads are calibrated correctly using the following the procedure.


    1. Check the wiring from the control panel to the last head on the run for proper polarity and continuity.
    2. Make sure each run terminates with an EOL resistor as specified by the control panel manufacturer.
    3. Apply power to the system. Check for alarm and troubles.
    4. If single detectors alarmed or went in trouble, check if there is a free space of at least 19 in. (50 cm) around these detectors. If the problem persists, replace these detectors or swap them with known good units. If also the good units alarm or go in trouble, the sensitivity may have been affected by the surrounding environment. Recheck if there are any obstructions around the detector which may reflect the light emitted by the detector. (See Figure 1 below)
    5. Activate the dry reed contact of each detector for 10 sec with a magnet until the detector alarms. Then reset the detector by removing the power for at least 3 seconds. After the reset, the detector will calibrate itself to the surrounding environment. Make sure that no objects or obstructions (like a ladder or the test tool SOLO330 itself) are within 19 inches of the detector during calibration for 2 minutes or until the head begins to flash normal. (See Figure 9 below for magnet replacement to trip Dry Reed Contact)


     *Note - After installation each detector must be calibrated. If there are any obstruction in front of the detector after the reset during its calibration (Electronic Function Test) the sensitivity of the detector may be affected.

    Electronic Functional Test

    1. Activate the dry reed contact (Section 5, Dry Reed Contact).
    2. Leave the magnet on the test tool by the dry reed contact for 10 sec. Count 10 flashes of the LED. The detector activates a test alarm and the LED turns red.



    • Operating Voltage: 9.7 V DC to 30 V DC
    • Current Consumption: Standby Alarm/Trouble
    • FCA-500 / FCA-500 with DRA-5 3 mA / 3 mA 47 mA / 52 mA
    • FCA-500-E / FCA-500-E with DRA-5 24 mA / 24 mA 47 mA / 58 mA
    • Alarm Output: Alarm resistance 680 or 0 (US only)

    Remote LED Output: 20 mA maximum

    Version history
    Last update:
    ‎05-16-2018 04:30 PM
    Updated by:
    Labels (1)