System Sensor B200S-LF-IV Intelligent Low-Frequency Sounder Base

The System Sensor B200S-LF-IV Intelligent Low-Frequency Sounder Base is an addressable audible detector base designed to provide a 520 Hz low-frequency alarm signal in fire alarm applications, particularly sleeping areas where low-frequency notification is required. The base combines an intelligent detector mounting base with an integral low-frequency sounder, allowing compatible fire alarm control panels to activate individual sounder bases or groups of bases according to programmed system events.

The B200S-LF-IV is the ivory version of the B200S-LF low-frequency sounder base. Its low-frequency output is designed around a fundamental frequency of 520 Hz ±10%, addressing NFPA 72 sleeping-space requirements and improving audible notification for sleeping occupants, including people with mild to severe hearing loss.

Product Functions

• Provides low-frequency audible fire alarm notification
• Produces a 520 Hz ±10% fundamental frequency
• Designed for sleeping-area fire alarm applications
• Functions as an intelligent detector mounting base
• Supports compatible addressable System Sensor detectors
• Allows individual or grouped sounder activation
• Supports fire alarm control panel programming
• Provides selectable 75 dBA or 85 dBA volume
• Supports ANSI Temporal 3 signaling
• Supports ANSI Temporal 4 signaling
• Supports March Time signaling
• Supports compatible custom tone patterns on selected control panels
• Recognizes System Sensor synchronization protocol
• Can operate as part of a synchronized general evacuation signal
• Uses a separate mounting plate for simplified installation
• Supports multiple junction box configurations
• Accepts 12 to 24 AWG wiring
• Ivory housing for installations requiring an ivory finish

Low-Frequency Sounder Operation

The primary function of the B200S-LF-IV is to provide a low-frequency audible alarm signal from the location of a compatible intelligent detector.

The low-frequency version produces a fundamental frequency of 520 Hz ±10% using a square wave or equivalent waveform. This frequency range is specifically intended to address sleeping-space notification requirements.

Research incorporated into modern fire alarm requirements has shown that a lower-frequency signal centered around 520 Hz can be more effective at waking sleeping occupants, including individuals with mild to severe hearing loss. For this reason, low-frequency notification is commonly used in sleeping areas such as hotels, apartments, dormitories, and other residential or institutional occupancies.

Addressable Sounder Control

The B200S-LF-IV operates as an intelligent sounder base rather than as a conventional continuously controlled detector sounder.

The B200S series sounder bases use the same address associated with the installed detector while appearing as a unique device type on the addressable loop. This arrangement allows a compatible fire alarm control panel to command an individual sounder or a programmed group of sounders to activate.

This intelligent control allows sounder operation to be tailored to the fire alarm system’s programmed sequence of operations rather than requiring every detector sounder to operate identically.

Selectable Sound Output

The B200S-LF-IV provides programmable audible output options that can be selected through compatible fire alarm control equipment.

Supported output options include:

• 75 dBA volume
• 85 dBA volume
• ANSI Temporal 3
• ANSI Temporal 4
• March Time
• Custom tone patterns on supported fire alarm control panels

The combination of selectable volume, tone, and grouping provides flexibility when configuring audible notification for different building areas and emergency conditions.

Temporal 3 & Temporal 4 Operation

The B200S-LF-IV supports multiple coded audible patterns.

ANSI Temporal 3 is commonly associated with fire alarm evacuation signaling. The B200S series also supports ANSI Temporal 4, allowing compatible fire alarm systems to provide a distinguishable audible pattern for applications where different emergency conditions need to be communicated.

Compatible fire alarm control panels may use the available tone options to provide different sounder responses based on the type of system event.

System Sensor Synchronization

The B200S-LF-IV recognizes the System Sensor synchronization protocol.

This capability allows compatible sounder bases to operate as part of a synchronized general evacuation signal when connected to a fire alarm control panel or power supply output capable of generating System Sensor synchronization pulses.

Synchronization can help maintain coordinated audible signaling between compatible notification appliances throughout the protected area.

Detector Compatibility

The B200S-LF-IV is designed for use with compatible System Sensor intelligent detectors and supported fire alarm control systems.

Honeywell documentation identifies the B200S-LF-IV as a compatible low-frequency intelligent sounder base for various intelligent detector families. Compatibility depends on the detector, communication protocol, and specific fire alarm control panel.

The compatible detector and control panel documentation should always be checked before installation because not every detector or fire alarm control panel supports every programmable function available from the sounder base.

Electrical Specifications

Published specifications for the B200S-LF family include:

Sounder Type: Intelligent low-frequency sounder base
Fundamental Frequency: 520 Hz ±10%
Audible Output Settings: 75 dBA or 85 dBA
Tone Options: ANSI Temporal 3, ANSI Temporal 4, March Time
Wire Gauge: 12 to 24 AWG
Operating Temperature: 32°F to 120°F / 0°C to 49°C
Relative Humidity: 10% to 93%, non-condensing
Synchronization: System Sensor synchronization protocol

Electrical power requirements and current draw should be calculated using the applicable System Sensor/Honeywell documentation for the selected operating mode and compatible control equipment.

Physical Dimensions

The B200S-LF-IV uses the same physical sounder-base platform as the B200S series.

Diameter: 6.875 in / 17.46 cm
Housing Color: Ivory
Product Configuration: Intelligent detector sounder base
Mounting Style: Separate mounting plate
Wire Gauge: 12–24 AWG

The separate mounting plate is designed to install on multiple junction box configurations, helping provide a cleaner finished installation without requiring an exposed surface-mount box in many applications.

Installation Information

The B200S-LF-IV uses a separate mounting plate that allows field wiring and mounting preparation to be completed before the sounder base and detector are installed.

Typical installation considerations include:

• Compatible intelligent detector selection
• SLC communication wiring
• Sounder power wiring
• Correct polarity
• Proper sounder base configuration
• Compatible fire alarm control panel programming
• Selection of required audible volume
• Selection of required tone pattern
• Sounder group programming where applicable
• System Sensor synchronization where required
• Secure detector installation into the sounder base
• Correct junction box and mounting arrangement

The mounting design supports various junction box sizes and helps simplify pre-wiring and final installation.

Installation must follow the documentation for the sounder base, installed detector, fire alarm control panel, and associated power supply equipment.

Sleeping Area Applications

The B200S-LF-IV is particularly suited to fire alarm installations containing sleeping areas.

The 520 Hz low-frequency signal is designed to meet NFPA 72 sleeping-space notification requirements applicable to supported installations.

Typical sleeping-area applications can include:

• Hotel guest rooms
• Apartment sleeping rooms
• College dormitories
• Assisted-living facilities
• Residential occupancies
• Institutional sleeping areas
• Other code-required sleeping spaces

The exact notification requirements depend on the occupancy, adopted code edition, system design, and authority having jurisdiction.

Testing & Maintenance

Testing should confirm:

• Proper communication with the fire alarm control panel
• Correct detector operation
• Proper B200S-LF-IV sounder activation
• Correct 520 Hz low-frequency audible output
• Correct programmed volume level
• Correct Temporal 3, Temporal 4, March Time, or programmed tone
• Individual sounder activation where programmed
• Group sounder activation where programmed
• Proper System Sensor synchronization where used
• Correct sounder power
• Secure detector-to-base connection
• Secure field wiring and terminal connections
• Proper restoration after alarm testing

Inspection should also verify that the sounder openings are not obstructed and that the detector and base have not been painted, physically damaged, contaminated, or altered in a manner that could interfere with operation.

Testing and maintenance should follow System Sensor/Honeywell instructions, applicable fire alarm control panel documentation, local requirements, and the facility’s established fire alarm inspection and testing procedures.

Product Identification

Manufacturer: System Sensor / Honeywell
Model: B200S-LF-IV
Product Type: Intelligent Low-Frequency Sounder Base
Primary Function: Addressable Detector Base with Audible Notification
Frequency: 520 Hz ±10%
Sound Wave: Square wave or equivalent
Volume Settings: 75 dBA / 85 dBA
Tone Options: ANSI Temporal 3 / ANSI Temporal 4 / March Time
Synchronization: System Sensor Sync Protocol
Housing Color: Ivory
Diameter: 6.875 in / 17.46 cm
Wire Gauge: 12–24 AWG
Operating Temperature: 32°F to 120°F / 0°C to 49°C
Relative Humidity: 10%–93%, non-condensing
Application: Intelligent Fire Alarm Detector Sounder Base / Sleeping-Area Notification

Protection & Applications

Suitable applications include:

• Commercial Fire Alarm Systems
• Intelligent Addressable Fire Alarm Systems
• Low-Frequency Fire Alarm Notification
• 520 Hz Audible Notification
• Sleeping-Area Fire Alarm Notification
• Detector Sounder Applications
• Individual Sounder Control
• Group Sounder Activation
• Synchronized Fire Alarm Notification
• Hotels
• Apartment Buildings
• Residential Buildings
• College Dormitories
• Assisted-Living Facilities
• Healthcare Facilities
• Hospitals
• Institutional Facilities
• Schools and Universities
• High-Rise Residential Buildings
• Mixed-Use Buildings
• Commercial Life Safety Systems

Download the Specification sheet in *.pdf format