Fire-Lite MMF-300 Addressable Monitor Module

The Fire-Lite MMF-300 is an intelligent addressable monitor module with one supervised Class A or Class B initiating device circuit (IDC) for normally open dry-contact fire alarm and supervisory devices. Designed for compatible Fire-Lite fire alarm control panels, it operates from 15-32 VDC directly through the two-wire signaling line circuit (SLC) and features rotary decimal addressing, a panel-controlled status LED, and high EMI/RFI immunity. The module includes a 47K-ohm end-of-line resistor for Class B wiring and mounts to a standard 4-inch square electrical box. It replaces the earlier Fire-Lite M300 monitor module.

Fire-Lite MMF-300 Intelligent Addressable Single-Input Monitor Module

The Fire-Lite MMF-300 is an intelligent addressable single-input monitor module designed to interface conventional dry-contact initiating devices with compatible Fire-Lite addressable fire alarm control panels. Manufactured by Fire-Lite Alarms, a Honeywell brand, the MMF-300 provides a supervised connection between the system's signaling line circuit (SLC) and a conventional initiating device circuit (IDC). This allows non-addressable devices to communicate alarm, supervisory, and circuit status conditions through an individually identifiable addressable module. Typical monitored devices include manual fire alarm pull stations, conventional heat detectors, waterflow switches, valve supervisory contacts, and compatible four-wire smoke detector alarm contacts. The module is suitable for commercial and institutional fire alarm installations in offices, schools, healthcare facilities, industrial properties, warehouses, and other buildings that use supported Fire-Lite intelligent fire alarm systems. The MMF-300 also serves as the manufacturer-designated replacement for the earlier Fire-Lite M300 monitor module in compatible installations.

The MMF-300 provides one supervised initiating device circuit configurable for NFPA Class B (Style B) or Class A (Style D) operation. In Class B applications, a supplied 47K-ohm end-of-line resistor is installed at the end of the initiating circuit to supervise field wiring and connected normally open contacts. In Class A applications, the initiating device wiring returns to the module, providing the fault-tolerant circuit arrangement specified in the manufacturer's installation instructions without an external end-of-line resistor. The module responds to polling from the fire alarm control panel and reports the normal, open, or shorted condition of the supervised IDC for processing according to the programmed device type. For conventional initiating devices, contact activation is transmitted through the module rather than requiring each contact to communicate independently with the control panel. Fire alarm and supervisory devices must be grouped and programmed according to their intended system functions; incompatible device categories should not be mixed on the same monitored circuit.

The Fire-Lite MMF-300 operates from a 15-32 VDC signaling line circuit and receives its operating power directly from the two-wire SLC connection. No separate auxiliary power supply is required for the module electronics. Manufacturer specifications identify a maximum current draw of 5.0 mA with the status LED illuminated and an average operating current of approximately 375 microamps under specified polling conditions. The monitored initiating device circuit supports a maximum wiring resistance of 1,500 ohms and a maximum IDC voltage of 11 volts, subject to the approved system configuration. The module incorporates high electromagnetic and radio-frequency interference immunity to support reliable communication in electrically demanding commercial environments. Built-in type identification allows compatible Fire-Lite control panels to recognize the device as a monitor module, while the low-current supervised input enables integration of compatible conventional dry-contact initiating equipment without requiring individual addressable sensors for every device.

The MMF-300 features two rotary decimal address switches for assigning an individual SLC address. Manufacturer documentation identifies address ranges of 01-159 for compatible MS-9600 Series panels and 01-99 for other supported legacy systems, with available addresses ultimately determined by the connected control panel and its approved configuration. The module includes a panel-controlled LED that flashes during normal communication and illuminates steadily during an alarm condition, subject to system programming and SLC current limitations. Electrical connections use SEMS screw terminals with clamping plates to simplify field wiring and provide secure termination of compatible conductors. Its standard-sized assembly measures approximately 4.5 inches high, 4 inches wide, and 1.25 inches deep (114.3 x 101.6 x 31.75 mm). It mounts directly to a standard 4-inch square electrical junction box with a minimum depth of 2-1/8 inches or to the separately available SMB500 surface-mount electrical box. The module is rated for ambient temperatures from 32 F to 120 F (0 C to 49 C) and relative humidity from 10% to 93%, non-condensing, supporting installation in appropriately protected indoor fire alarm equipment locations.

The Fire-Lite MMF-300 is designed for compatible intelligent fire alarm systems requiring supervised monitoring of normally open dry-contact alarm and supervisory devices. It operates with approved Fire-Lite signaling line circuits and supports the manufacturer's LiteSpeed communication protocol on compatible control panels, providing individual point identification and efficient status reporting. The MMF-300 is distinct from the MMF-301 miniature monitor module, which provides a compact Class B-only input without the same standard-sized mounting arrangement. It also differs from the MMF-302 interface module, which is specifically designed to monitor compatible conventional two-wire smoke detectors using an external regulated power source. The MDF-300 dual monitor module provides two independent Class B inputs, whereas the MMF-300 supervises a single Class A or Class B input. The MMF-300 is intended for integration into listed, compatible fire alarm systems and must be installed in accordance with the manufacturer's SLC wiring manual, applicable NFPA 72 requirements, and local authority having jurisdiction. Combining single-point addressable monitoring, Class A/Class B circuit flexibility, SLC-powered operation, rotary addressing, and standard electrical-box mounting, the MMF-300 provides a practical interface for expanding and maintaining commercial Fire-Lite addressable fire alarm installations.