Bosch FAP-520 Automatic Fire Detectors, LSN Improved Version

1 Product Description

The 520 Series Fire Detectors combine LSN improved technology with aesthetic flush-mounted installation. They are compatible with LSNi and classic LSN fire panels. Detectors are available in white and transparent versions with color toning inserts for optimal environmental matching. Their smooth, easily-cleaned surface and lack of an optical labyrinth make them suitable for high-dust areas. The low-profile, flush-mounted design minimizes protrusions.

Featuring two separate optical sensor systems, the detectors are resistant to interference. The scattered light principle is used for detection, with contamination levels monitored and compensated for. The FAP-OC 520 model includes an additional gas sensor for enhanced fire evaluation, improving immunity to deceptive alarms.

Integrated rotary switches allow for automatic or manual address allocation. The FAP-520 detectors connect directly to the Local Security Network (LSN).

Accessories

Detectors are typically mounted flush with the ceiling using the FAA-500 Series Bases, installed in a ceiling mount back box (FAA-500-BB) or a built-in housing for concrete ceilings (FAA-500-CB). A surface mount back box (FAA-500-SB-H) is available for applications where recessed mounting is not possible, offering a seal for damp rooms.

Base variants with relays are available for specific applications, such as emergency door control. All bases feature integrated strain relief for cables and accessible connection terminals suitable for cables up to 3.3 mm².

An innovative push-in/push-out concept facilitates quick detector insertion and exchange. A special service accessory is available for detector testing and exchange.

Overview of the 520 Series Detectors and Accessories

Detectors LSN improved:

• FAP-O 520: Optical Fire Detector LSN improved, white
• FAP-O 520-P: Optical Fire Detector LSN improved, transparent with color toning inserts
• FAP-OC 520: Multisensor Fire Detector LSN improved, optical/chemical, white
• FAP-OC 520-P: Multisensor Fire Detector LSN improved, optical/chemical, transparent with color toning inserts

Trim Rings:

• FAA-500-TR-W: White Trim Ring for detectors 500 and 520 Series
• FAA-500-TR-P: Transparent Trim Ring with color toning inserts for detectors 500 and 520 Series

LSN Detector Bases:

• FAA-500: LSN Detector Base
• FAA-500-R: LSN Detector Base with Relay

Mounting Boxes:

• FAA-500-BB: Ceiling Mount Back Box
• FAA-500-CB: Built-in Housing for concrete ceilings
• FAA-500-SB-H: Surface Mount Back Box with damp room seal

Service Accessories:

• FAA-500-RTL Detector Exchanger
• FAA-500-TTL Test Adapter with Magnet

1.1 System Description

All 520 Series detectors feature two optical sensors and a pollution sensor. The FAP-OC 520 adds a gas sensor. Detector sensitivity is programmable via the LSN network using programming software. Sensor signals are analyzed by an internal processor. The combination of optical and gas sensors in the OC detector allows for use in environments with minor smoke, steam, or dust, triggering alarms only when specific signal combinations occur.

1.2 Configuration of the Detector

The detector front panel includes:

• 1: Optical sensor
• 2: Receiver (photo diodes)
• 3: Transmitter (LEDs)
• 4: CO sensor (only OC-variants)
• 5: Two-color LED (red = alarm, green = test mode/trouble)
• 6: Pollution sensor
• 7: Measuring area

1.3 Functional Description of the Sensor Technology

Optical sensor (smoke sensor): Operates on the scattered light principle. LEDs emit light into the measuring area, and smoke particles scatter this light onto photo diodes, generating an electrical signal. Electronic filtering and phase-locked rectification mitigate interference from daylight and artificial lighting.

Chemical sensor (CO gas sensor): Detects carbon monoxide (CO), hydrogen (H), and nitrogen monoxide (NO) produced by fires. The measuring principle involves CO oxidation on an electrode, generating a current proportional to gas concentration. The sensor is monitored for internal capacity, and a malfunction signal is sent if it falls outside the permitted range, with the detector reverting to optical-only operation.

Pollution sensor: Continuously measures and evaluates the contamination level of the detector surface. A three-stage contamination display is available for service.

1.4 LED Operation

The two-color LED indicates operation and alarm statuses. Sensors are self-monitored, and sensitivity is self-adjusted. In case of alarm, the LED flashes red. The detector returns to standby after the alarm is reset and the cause is removed.

2 Planning Notes

2.1 General Notes

Notice! The 520 Series Detectors are for indoor use only and must be installed in the provided FAA-500 Series Bases, which are then installed in either an FAA-500-BB Ceiling Mount Back Box or an FAA-500-SB-H Surface Mount Back Box.

Country-specific standards and guidelines must be followed. Planning for FAP-OC 520 and FAP-O 520 follows guidelines for optical detectors (EN 54, VDS 2095).

A hemispherical space with a 50 cm radius must remain clear below the detector. Ensure no objects obstruct this area or cover the detector surface.

Notice!

• Detectors must be installed out of arm's reach. Minimum installation height recommended by Bosch is 2.70 m.
• Do not install in rooms with high-intensity infra-red data transmission.
• Detectors must not be exposed to direct sunlight.
• Maintain a minimum distance of 50 cm from lamps.
• Avoid mounting in the direct cone of light from lamps.
• Bases are equipped with a spring for mounting in concrete/wooden ceilings (blue marking). A softer spring (yellow marking) is provided for false ceiling panels (note: this may not meet EN54-7).
• Maximum permitted air speed is 20 m/s.

2.2 Network Topologies for LSN Improved

LSN improved detectors support loop, stub, T-tap, and mixed loop/T-tap topologies. Mesh structures are not supported. T-taps are allowed on stubs or loops, with a maximum of 254 elements per network. Connections can be placed anywhere along the LSN line.

Notice! Planning must account for total current and line resistance to ensure a minimum operating voltage of 15 VDC per detector. Use the Safety Systems Designer (SSD) for detailed planning. If an LSN classic device is used, only loops or stubs are permitted; T-taps cannot be configured.

3 Installation

Notice! 520 Series Detectors must be installed with an FAA-500 Detector Base in an FAA-500-BB Ceiling Mount Back Box or FAA-500-SB-H Surface Mount Back Box.

Notice! Bases have a spring for concrete/wooden ceilings (blue marking). A softer spring (yellow marking) is for false ceilings, but may void EN 54-7 shock resistance if subjected to vibrations (> 350 m/s).

3.1 Ceiling-Mount Back Box

The FAA-500-BB ceiling-mount back box is made of white polypropylene with four cable bushings suitable for cables up to 1.4 cm diameter. It accommodates approximately 30 cm of cable length.

Notice! For false ceilings, the maximum thickness is 32 mm, and a free height of at least 11 cm is required above the ceiling.

Drill a 130 mm diameter hole in the false ceiling.

The back box has a bracket (1), screws for fastening the base (2), and cable bushings (3).

Installation Steps:

1. Pull the cable through a cable bushing. Use a cable tie to secure the cable sheath.
2. Insert the back box into the false ceiling from below.
3. Align the triangular marking (M) on the back box with the oblong windows on the detector for a straight line.
4. Tighten the brackets (1).

Caution! Cordless screwdrivers are not recommended for soft false ceilings.

3.2 Detector Base/Detector Base with Relay

The base housings are made of white polycarbonate. Screw terminals ensure secure electrical connections for cables from 0.3 mm² to 3.3 mm². Three mounts are provided for cable ties.

Notice! Remote indicators cannot be connected to relay bases.

Connecting the base: Wire the LSN base according to the labeling in the outer ring (3).

Plan view of base:

• 1: Connection terminals
• 2: Mount for cable ties
• 3: Labeling on LSN connections
• 4: Fastening slot

Connection of bases:

* Terminals for looping through the power supply for other LSN elements

** For switching capacity refer to Detector Base, page 28

The base can be rotated up to 20° for fine alignment.

Installation Steps:

1. Place the base in the ceiling mount back box, aligning the marking on the backbox (1) with the single guide-groove (2).
2. Turn the base until the fastening screws are centered in the long slots (3).
3. Adjust the bases to appear in a line.
4. Tighten the four screws.

3.3 Address Allocation

Detector addresses are set using three rotary switches on the back of the device. Use a flat-bladed screwdriver. Factory default address is 000.

3.4 Detector and Trim Ring

Notice! The packaging for detectors with a C sensor is tear-resistant PE-ALU film and should be cut open carefully. Remove the protective film only when the detector is ready for fitting.

Inserting the color rings

Notice! Do not switch detector front plates, as the pollution sensor is calibrated individually for each detector and its front plate. Switching plates can lead to incorrect pollution readings.

Installation Steps:

1. The detector front panel (1) is secured by a snap-fit hook (2) on the triple groove. Insert the supplied opener (3) into the slot above the hook (4), fasten with the thumb, and rotate the front panel counter-clockwise.
2. Place the desired color rings (5) on the front panel (1), then place the detector on top. The front panel fits in only one position.
3. Rotate the front panel clockwise until it engages. Ensure the sensor window is unobstructed.
4. Insert the desired color ring into the FAA-500-TR-P Trim Ring (6).

Inserting the detector and trim ring

Notice! The FAA-500-RTL Detector Exchanger is recommended for inserting and removing detectors.

1. Push the trim ring onto the base until it clicks into place (7).
2. Remove the protective film from the detector surface. (Note: Initial setup may show an O-malfunction if the film is not removed).
3. Insert the detector, pressing gently upwards until it clicks and locks. Guide grooves ensure correct positioning. For high installations, note the contact faces (8) are on the same side as the single guide-groove (9).

Removing the detector and trim ring:

1. Gently push the detector upwards in the middle to release the lock.
2. Lift the trim ring off on one side.

3.5 Built-in Housing for Concrete Ceilings

The FAA-500-CB Built-in Housing is used for installing detectors in concrete ceilings, allowing easy conduit connection. It is placed on the concrete form, fastened, and secured against floating. Nails should be placed in the Styrofoam area to avoid interference when cutting.

Pipe or cable inlets are made with a universal cutting tool. After removing form-boards, the front part (1) is opened with a fret-saw or hole saw. The FAA-500-BB Ceiling Mount Back Box is then inserted into the housing.

3.6 Surface Mount Back Box

The FAA-500-SB-H Surface Mount Back Box supports flush and surface cable ducting and includes a seal for damp rooms. Side knockouts are for surface cable duct, and two bottom openings are for flush cable duct. Using 13.5 mm cable glands, the maximum cable gauge is 12 mm.

Mounting is done via elongated slots or four mounting holes for direct attachment to 4-inch electrical boxes or single-gang switch boxes.

The base is mounted inside the back box via four fastening points.

3.7 Remote indicator

A Remote Indicator is required when the detector is not directly visible or is mounted in false ceilings or floors. Install remote indicators in corridors or access pathways.

Notice! When using unshielded cables, the maximum cable length for the remote indicator is 3m. Shielded cables have no length limitation.

Installation of the FAA-420-RI Remote Indicator:

Warning! Malfunction and Damage: If the connected detector's current consumption exceeds 20 mA, it can cause malfunction or damage to the remote indicator. Ensure consumption does not exceed 20 mA and use Bosch detectors with internal resistors limiting current consumption.

Before assembly:

1. Unlock the snap-fit hook and carefully lift the cap.
2. Remove the connection board.
3. Mount the base plate directly onto a dry, level surface with two or four screws.

For surface-mounted cables: Break out the prepunched cable entries.

For flush-mounted cables: Insert the cable through the opening under the connection board.

Secure the cable with a zip tie on the base plate.

FAA-420-RI-DIN

Warning! Malfunction and Damage: Note the maximum permitted current supply and input voltage range for functional modes.

Wire the remote indicator as shown.

FAA-420-RI-ROW

Wiring and Operation:

Operate in modes 1 and 3 only when connected to LSN detectors.

Installation Steps:

1. Place the cap on the base plate, ensuring the two hooks insert into the slits.
2. Press the cap lightly onto the base plate until the snap-fit hook engages.

4 Programming

LSN detectors are programmed according to the required operating mode using programming software on a PC or laptop connected to the fire panel. The sensitivity of multisensor detectors is set by specifying the operating location, which determines the characteristic diagram for fire and disturbance evaluation.

If the optical sensor sensitivity is set to low, the alarm triggers only with high smoke and CO levels simultaneously, typical for smoldering fires. Programming and linking detectors with algorithms enhances reliability and reduces false alarms.

Operating locations for multisensor fire detector (FAP-OC 520)

Operating location and recommended setting for optical fire detector (FAP-O 520)

Notice! For function tests, the detector must be switched to test mode via the fire panel or a magnet on the reed switch.

5 Maintenance and Service

Notice! 520 Series Detectors do not require removal from bases for routine maintenance. Replacement due to design changes or damage should be performed by qualified personnel. The system should be offline during replacement, with alternative evacuation arrangements made.

Maintenance and inspection should be carried out regularly by trained personnel, with Bosch recommending annual functional and visual inspections. Remote maintenance is permitted for certain procedures.

FAP-OC 520 Notice! Due to the gas sensor's life expectancy, the FAP-OC 520 detector switches off its C sensors after approximately 5 years. It continues to function as an O detector, with a fault indication on the fire panel. Exchange the detector immediately to maintain detection reliability.

Notice! Cleaning intervals depend on environmental conditions. Clean with a soft cloth and plastic cleaner in test mode only.

Refer to:

• Inspection Procedure for FAP-O 520, page 25
• Inspection Procedure for FAP-OC 520, page 24

5.1 Notes for the Service

The fire panel display provides access to the serial number, contamination level, operating hours, and analog values of configured detectors.

Contamination level:

Operating hours:

Displays operating time in hours since initial operation.

Current measurement values:

Analog smoke value of the scattered light sensor:

CO value: Current measurement value of the CO sensor (FAP-OC 520 only). Maximum value is 1023.

5.2 General Notes for Detector Testing

The FAP-OC 520 detector includes a CO sensor for improved response and stability in critical environments. For fire detection, FAP-520 detectors use the time behavior of fire characteristics. For functional tests, the detector must be switched to test mode via the fire panel or a magnet on the reed switch.

Notice! Detectors programmed for two-detector dependency must be tested using the first alternative (test mode).

Required for detector test:

• Detector test device for optical fire detector
• FAA-500-TTL test adapter with magnet
• For OC detectors: CO testing gas

5.3 Inspection Procedure for FAP-OC 520

5.3.1 Option 1

Use remote functional testing as per the manufacturer's approved test procedure.

5.3.2 Option 2

1. Switch the detector zone to test mode on the central unit. This enables revision operation for detector testing.
2. In revision operation, individual sensors trigger with the corresponding test device. All sensors must trigger simultaneously for an alarm. Use CO test aerosol for the C sensor and cover for the O sensors. No O testing gas is required.
3. Hold the test device flush with the trim ring, sealing it tightly. Ensure the beaker does not tilt.
4. Spray CO testing gas for approximately 1 second. Keep the test head over the detector until triggered. Gas distribution and trigger time can take up to 20 seconds.
5. Covering both scattered light areas triggers both optical sensors simultaneously.
6. The detector triggers an alarm, and the red alarm LED flashes.

5.3.3 Option 3

Test in normal operation using a test device with a magnet. Notice! Ensure alarms are not passed to higher-level systems. Programmed activations of the central unit are retained.

The reed switch (Pos. R) is located at approximately 2 o'clock relative to the CO sensor (Pos. CO) at 12 o'clock.

Bring the magnet close to the reed switch.

5.4 Inspection Procedure for FAP-O 520

5.4.1 Option 1

Use remote functional testing as per the manufacturer's approved test procedure.

5.4.2 Option 2

1. Switch the detector zone to test mode on the fire panel. This enables revision operation for detector testing.
2. Hold a sufficiently large object (e.g., detector test device or exchanger) in both scattered light areas until an alarm is triggered. No O testing gas is required.

5.4.3 Option 3

Test in normal operation using a test device with a magnet. Notice! Ensure alarms are not passed to higher-level systems. Programmed activations of the central unit are retained.

The reed switch (Pos. R) in O detectors is located at approximately 2 o'clock relative to the detector LED at 12 o'clock.

The LED flashes green once per second after the reed switch is triggered. The detector remains in test readiness for 60 seconds with auto-set parameters (e.g., reduced delay time to 15 seconds). The green LED flashes as long as the detector is in test mode.

Hold the test device flush with the trim ring. Covering the scattered light areas triggers both optical sensors simultaneously (no O testing gas required).

The detector triggers the alarm, and the red alarm LED flashes.

Notice! Programmed intermediate alarm storage may result in longer trigger times.

5.5 Repair

In case of any defect, the entire module/device is exchanged.

5.6 Disposal

Dispose of unusable electrical and electronic devices in compliance with applicable regulations (e.g., WEEE in Europe). Do not dispose of with normal household refuse.

The packaging bag for detectors with a C sensor is made of tear-resistant PE-ALU laminated film and may be disposed of with household garbage.

6 Technical Data

6.1 Detector and Trim Ring

6.2 Detector Base

6.3 Mounting Boxes

FAA-500-BB Ceiling Mount Back Box

FAA-500-CB Built-in Housing for concrete ceilings

FAA-500-SB-H Surface Mount Back Box with damp room seal

6.4 Remote indicator

Technical specifications

7 Appendix

7.1 Abbreviations

7.2 Order Overview

7.2.1 Detector and Trim Ring

Color toning inserts for FAP-O 520-P, FAP-OC 520-P and FAA-500-TR-P:

7.2.2 Detector Bases/Remote indicators

7.2.3 Mounting Boxes

7.2.4 Service tools/accessories

* DU = delivery unit, PE = pieces, PU = packaging unit