Fire-Lite MMF-301 — an addressable miniature monitor module that provides one two-wire Style B (Class B) initiating device circuit for normally open dry-contact devices. At 1.3″ H × 2.75″ W × 0.65″ D it is small enough to be installed in a single-gang junction box directly behind the unit it monitors.
The MMF-301 is intended for use in intelligent, two-wire systems where the individual address of each module is selected using rotary switches. It provides a two-wire initiating circuit for normally open contact fire alarm and security devices — typically a single device or a zone of dry contacts such as manual pull stations, waterflow switches, or the contacts of four-wire detectors. Its small size and light weight allow it to be installed without rigid mounting. The module connects by wire pigtails rather than terminal screws: red (+) and black (−) to the positive and negative loop power leads of the Signaling Line Circuit, and violet (+) and yellow (−) to the two-wire normally open initiating loop. The required 47K end-of-line resistor (ELR-47k) is included, and the module can be used to replace an M301 module in existing systems.
Specifications
| Model |
MMF-301 |
| Type |
Addressable miniature monitor module, one two-wire Class B (Style B) IDC |
| Nominal operating voltage |
15–32 VDC |
| Average operating current |
375 µA (group poll); 350 µA (direct poll) |
| Maximum current |
600 µA (communicating, IDC shorted) |
| EOL resistance |
47K ohms (ELR-47k included) |
| Maximum IDC resistance |
1,500 ohms |
| Maximum IDC voltage |
11 volts |
| Maximum IDC current |
450 µA |
| Addressing |
Rotary switches (tens and ones) |
| Connection |
Wire pigtails; 6″ minimum wire length |
| Temperature range |
32°F to 120°F (0°C to 49°C) |
| Humidity |
10% to 93% non-condensing |
| Dimensions |
1.3″ H × 2.75″ W × 0.65″ D |
Installation notes
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No LED and no Class A option: the MMF-301 is the miniature version of the MMF-300 and excludes the LED and the Class A option. Do not specify it where a local visible indicator or a Class A initiating circuit is required — use the full-size MMF-300 instead.
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Pigtails, not terminal screws: the module is wired by coloured wire leads and is intended to be wired and mounted without rigid connections inside a standard electrical box. Allow at least 6″ of wire.
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End-of-line resistor: install the specified 47K EOL resistor to terminate the initiating loop; the ELR-47k ships with the module.
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Circuit limit: maximum initiating device circuit resistance is 1,500 ohms.
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No surface box: the SMB500 surface mount box is used for all Fire-Lite modules except the MMF-301 and M301.
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Compatibility: to ensure proper operation, connect this module only to listed compatible system control panels. Available address range is panel dependent — refer to the panel manual.
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Before installing: if the module is added to an existing operational system, inform the operator and the local authority that the system will be temporarily out of service, and disconnect power to the control panel before installing.
Related models
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MMF-300 — full-size addressable monitor module for one zone of normally open dry-contact initiating devices; mounts in a standard 4.0″ box and may be configured for either a Class B or Class A IDC
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MDF-300 — dual monitor module; same as the MMF-300 except it provides two Class B-only IDCs
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MMF-302 — addressable monitor module for one zone of conventional two-wire detectors; requires resettable 24 VDC power
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MMF-300-10 — ten-input monitor module for cabinet mounting
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M301 — the legacy module the MMF-301 replaces in existing systems
Specifications taken from the Fire•Lite Alarms installation and maintenance instructions “MMF-301 Monitor Module,” document I56-3654-002, with model positioning from the Fire•Lite data sheet “ES-50X Series Intelligent Addressable Fire Alarm Control Panels,” document DF-60953:D (3/27/2023). Manufacturer specifications are subject to change without notice.
