Fire-Lite MMF-301 Mini Monitor Module

The Fire-Lite MMF-301 is a miniature addressable monitor module for Class B (Style B) fire alarm initiating device circuits, designed for compatible Fire-Lite intelligent control panels. Featuring 15-32VDC signaling line circuit (SLC) operation, rotary address selection, and a 47k-ohm end-of-line resistor, it supervises normally open dry-contact devices such as manual pull stations, waterflow switches, and heat detectors. The compact module measures 1.3 x 2.75 x 0.5 inches, mounts inside a standard single-gang electrical box, and receives power directly from the SLC without requiring an external power supply.

Fire-Lite MMF-301 Miniature Addressable Fire Alarm Monitor Module

The Fire-Lite MMF-301 Mini Monitor Module is a compact, intelligent addressable interface designed to connect conventional fire alarm initiating devices to compatible Fire-Lite addressable fire alarm control panels. Manufactured by Fire-Lite Alarms, a Honeywell brand, the MMF-301 provides one supervised Class B (Style B) initiating device circuit (IDC) for monitoring normally open dry-contact equipment. Supported applications include manual fire alarm pull stations, conventional heat detectors, sprinkler waterflow switches, and supervisory contacts connected according to the fire alarm system design. Its miniature construction allows the module to be installed inside a standard single-gang junction box directly behind the monitored device, eliminating the need for a separate surface-mounted module enclosure in compatible installations. The MMF-301 provides individual addressable identification and supervised alarm reporting for commercial and institutional fire protection systems.

The MMF-301 operates from a 15-32VDC signaling line circuit and receives its operating power directly from the compatible two-wire SLC connection. The manufacturer specifies an average current consumption of 375 microamps during group polling or 350 microamps during direct polling, with a maximum of 600 microamps while communicating with the initiating circuit shorted. Its supervised initiating circuit uses an included 47k-ohm end-of-line (EOL) resistor to monitor connected field wiring for normal, alarm, and trouble conditions. The installation instructions specify a maximum IDC resistance of 1,500 ohms, maximum IDC voltage of 10.1V, and maximum IDC current of 240 microamps. Built-in electromagnetic and radio-frequency interference resistance supports reliable communication in appropriately designed fire alarm installations. The MMF-301 is intended for dry-contact monitoring and does not provide operating power to conventional two-wire smoke detectors.

Designed for intelligent fire alarm monitoring and addressable system expansion, the Fire-Lite MMF-301 communicates with the fire alarm control panel through the SLC and reports the condition of its connected initiating device circuit. Two integrated rotary address switches allow installers to assign a unique module address without a separate programming tool. Legacy Fire-Lite documentation identifies addressing from 01 through 99 on compatible MS-9200 systems and up to 159 on supported MS-9600 Series panels, with actual address availability determined by the control panel and firmware. The module's built-in identification automatically identifies it as a monitor module to compatible Fire-Lite control equipment. A single MMF-301 can monitor an approved device or a conventional zone of normally open initiating contacts, allowing existing non-addressable field devices to be incorporated into an intelligent addressable fire alarm system. The module can also replace a legacy Fire-Lite M301 monitor module in approved existing installations.

The Fire-Lite MMF-301 features four factory-attached, color-coded wire leads that simplify field wiring and allow the module to fit inside confined electrical boxes. The red positive and black negative conductors connect to the compatible SLC, while the violet positive and yellow negative conductors connect to the normally open initiating device circuit. A supplied 47k-ohm ELR-47K resistor terminates the Class B field wiring for circuit supervision. The compact module can be positioned behind an initiating device without rigid mounting, provided sufficient electrical box space and code-compliant wiring arrangements are available. Its address selection switches remain accessible during installation, and the module's lightweight construction facilitates replacement and servicing. The MMF-301 does not incorporate a notification appliance output, integrated control relay, or local status LED; alarm and supervisory indications are processed by the connected fire alarm control panel.

The Fire-Lite MMF-301 measures 1.3 inches high, 2.75 inches wide, and 0.5 inches deep, with factory-attached leads extending at least 6 inches. The manufacturer specifies an operating temperature range of 32 F to 120 F (0 C to 49 C) and relative humidity from 10% to 93%, non-condensing, making the module suitable for protected indoor fire alarm installations. Its supervised, power-limited circuitry is designed for integration with listed compatible fire alarm control panels and must be installed according to the appropriate SLC wiring manual and local fire alarm requirements. The MMF-301 provides a space-efficient alternative to the larger MMF-300 monitor module where only one Class B initiating circuit is required. Unlike the MMF-300, the miniature MMF-301 does not support Class A initiating wiring or provide an integrated status LED. Honeywell currently identifies the MMF-301 as a discontinued product, making verification of replacement availability and system compatibility important when servicing existing installations.