Mircom MIX-5251RAP Intelligent Rate-of-Rise Heat Detector

The Mircom MIX-5251RAP Intelligent Rate-of-Rise Heat Detector provides addressable thermal detection for compatible Mircom fire alarm systems. It combines a 135°F (57°C) fixed-temperature alarm point with rate-of-rise detection, providing two methods of detecting potentially dangerous temperature conditions.

As part of Mircom’s Advanced Protocol intelligent thermal sensor family, the MIX-5251RAP features a thermistor-based sensing circuit, low-profile plug-in construction, rotary addressing, and dual LED indication. Its combination of fixed-temperature and rapid temperature-rise detection makes it suitable for a variety of commercial and institutional fire alarm applications.

Fixed Temperature and Rate-of-Rise Detection

The Mircom MIX-5251RAP activates when the temperature reaches its fixed 135°F (57°C) threshold. In addition, its rate-of-rise function responds when temperature increases at more than 15°F per minute (8.3°C per minute).

This dual detection method allows the sensor to respond to a rapid increase in temperature even before the fixed-temperature threshold is reached.

Advanced Protocol Communication

The MIX-5251RAP supports Mircom Advanced Protocol (AP) communication. This high-speed protocol uses group polling and interrupt functionality to improve communication between intelligent devices and compatible fire alarm control equipment.

Advanced Protocol supports up to 318 devices per SLC circuit on compatible systems. The detector is also backward compatible with CLIP mode for applicable legacy installations. Rotary address switches support addresses 01–159 in AP mode and 01–99 in CLIP mode.

Key Features

• 135°F (57°C) fixed-temperature detection
• Rate-of-rise detection above 15°F/minute
• Advanced Protocol with CLIP compatibility
• Dual LEDs for 360° visual indication
• Rotary address selection
• Low-profile plug-in construction

Electrical Specifications

The Mircom MIX-5251RAP operates from 15 to 32 VDC peak. Standby current is approximately 300 µA at 24 VDC, while maximum LED current is 6.5 mA at 24 VDC.

Its low standby current helps minimize SLC loading while maintaining addressable communication with the compatible fire alarm control panel.

Operating Temperature and Humidity

The MIX-5251RAP has an operating temperature range of -4°F to 100°F (-20°C to 38°C). Its specified operating humidity range is 10% to 93% relative humidity, non-condensing.

These environmental specifications make the detector suitable for many indoor commercial and institutional fire alarm applications.

Low-Profile Detector Design

The Mircom MIX-5251RAP measures approximately 2.0 inches (51 mm) high. Its diameter is approximately 6.1 inches (155 mm) when installed in a B210LP base and 4.1 inches (104 mm) when installed in a B501 base. The detector weighs approximately 4.8 oz. (137 g).

Compatible mounting options include the B210LP flanged base and B501 flangeless base. Mircom also lists relay, isolator, and sounder base options within this detector family.

Dual LED Status Indication

The MIX-5251RAP incorporates two LEDs positioned to provide 360-degree visibility. The LEDs provide detector status indication and can be latched on by the fire alarm control panel during an alarm condition.

Remote LED annunciation is also available with compatible accessories when a separate visual indicator is required.

Commercial Fire Alarm Applications

The Mircom MIX-5251RAP can provide addressable heat detection in offices, schools, healthcare facilities, hotels, commercial buildings, institutional properties, and other compatible fire alarm installations.

Mircom documentation identifies these intelligent thermal sensors for open-area protection with spacing capability up to 50 feet where permitted by the UL 521 listing and applicable installation requirements.

System Compatibility

The MIX-5251RAP requires compatible addressable communications and should only be connected to listed-compatible fire alarm control equipment. Current Mircom documentation continues to identify the model as an Advanced Protocol rate-of-rise heat detector in compatible system documentation.

The MIX-5251RAP is a legacy model. Mircom announced that new U.S. orders for this detector would be discontinued after February 28, 2022. Mircom’s newer MIX-5351RAP provides 135°F fixed-temperature and rate-of-rise thermal detection as part of the Select Series.

Overall, the Mircom MIX-5251RAP Intelligent Rate-of-Rise Heat Detector combines 135°F fixed-temperature detection, rapid temperature-rise detection, Advanced Protocol communication, and a low-profile addressable design for compatible Mircom fire alarm systems.

MIX-5251RAP Datasheet