Products Details

MRI-2251TMB 200 Series Dual Photo, Heat Intelligent Sensor


From the smallest business to the largest facility or campus, small conventional panels feature large capacity power supplies and easy front panel programming while large intelligent systems lead the market in sophisticated features including distributed emergency audio and are remarkably easy to configure and program. In addition to systems, Secutron™ also offers the most complete line of advanced detection industry with the advanced system features required by emerging fire codes and new protection design practices. Large intelligent networked systems support fully redundant network modularity, graphic display annunciation/monitoring, building management system integration, programmable smoke control and multi-channel emergency communications across buildings, campuses or communities. Secutron™ systems are also supported with the largest selection of detectors, signaling devices and accessory devices, including intelligent power supplies.

Model MRI-2251TMB is a photoelectric smoke detector with supplementary 135°F thermal. Also known as Acclimate™, it uses advanced on-board software to combine the signals from the photo and thermal elements. The MRI-2251TMB is a true multicriteria detector capable of rejecting nuisance sources, but still responding quickly to real fires. Acclimate has the capability of adjusting its sensitivity according to the type of environment that it is installed in.

Intelligent Low Profile Detectors Features:
• Sleek, low profile design
• Detectors are equipped with a built-in analog communications module
• Smoke detectors are available with photoelectric or ionization technology
• Photoelectric detectors are available with additional fixed temperature detection
• Heat detectors are available as fixed temperature or fixed temperature with rate-of-rise detection
• Dual LEDs indicate communications and activate steady when in alarm
• Low profile base provides easy interchangeability
• Low standby current
• Rotary address switches
• Magnetic test feature
• Superior EMI protection
• Sealed against dirt, insects, and back pressure 

Mounting Bases Features:

• Bases enable quick and secure detector plug-in
• SEMS screws provide easy wiring connection
• Support for 12-24 AWG provides installation flexibility
• Multiple accessory options provide mounting flexibility
• Sounder bases are compliant with UL 464 and UL 864 Diameter


Intelligent Low Profile Detectors Specifications:

Voltage Range   Thermal Ratings  
15 - 32 volts DC peak Fixed Temperature Setpoint: 135°F (57°C) Rate of Rise Detection: 15°F/min. (8.3°C/min.) High Temperature: 190°F (88°C)  
Standby Current  
150 uA @ 24 VDC (without communication, LED off)
200 uA@ 24 VDC (one communication every 5 sec. with LED enabled)
Operating Temperature Range  
Ion/Photo: 32°F to 120°F (0°C to 49°C)
Photo with Thermal: 32°F to 100°F (0°C to 38°C) Thermal: -4°F to 100°F (-20°C to 38°C)
High Temperature: -4°F to 150°F (-20°C to 66°C) Pinnacle: 32°F to 100°F (0°C to 38°C)
Photo/Photo with Thermal:
250 uA @ 24 VDC (without communication, LED off)
300 uA@ 24 VDC (one communication every 5 sec. with LED enabled)
230      μA      @      24VDC       (without       communication) 330 μA @ 24VDC (one communication every 5 sec. with LED enabled)
UL Listed Velocity Range  
Ion: 0 - 1200 fpm (0 - 6.1 m/sec)
Photo/Photo with Thermal: 0 - 4000 fpm (0 - 20 m/sec)
Pinnacle: 0 - 4000 fpm (0 - 20 m/sec)
LED Current (max.)  
6.5 mA @ 24 VDC (on)  
Insect Screen Hole Size  
Photo: 0.016 inch (0.41mm) nominal Ion: 0.035 inch (0.89mm) nominal  
2.0 inches (51 mm)
1.66 inches (42 mm) - Pinnacle
Self Diagnostics (PinnacleTM)  
Initiated by control panel Activated by test magnet  
6.1 inches (155 mm) Installed in B210LP Base
4.1 inches (104 mm) Installed in B501 Base
4.0 inches (102 mm) - Pinnacle
Smoke Sensitivity (PinnacleTM)  
9 levels: 0.02, 0.03, 0.05, 0.10, 0.20, 0.50, 1.00, 1.50, 2.00%/ft.
(0.06, 0.10, 0.16, 0.33, 0.66, 1.65, 3.24, 4.85, 6.41%/m obscuration)
Shipping Weight  
Heat: 4.8 oz. (137 g)
Photo/Photo with Heat: 5.2 oz. (147 g) Ion: 5.4 oz. (154 g)
Pinnacle: 5.6ox. (159 g)
Drift Compensation (PinnacleTM)  
High sensitivity maintenance alert signal Low sensitivity maintenance alert signal Maintenance urgent signal  
Relative Humidity  
10% - 93% non condensing  

 Mounting Bases specifications: 
  B224RB/B224BI Electrical  Ratings
Operating Voltage
15 to 32 VDC (powered by SLC)
Standby Current
170/450 µA max.
Set Time (B224RB only)
Short Delay: 60 to 100 msec
Long Delay: 6 to 10 sec
Reset Time (B224RB only)
20 msec max.
Relay Characteristics (B224RB only)
2 coil latching relay 1 Form C contact UL/ULC Rating:
0.5 A @ 125 VAC
0.9 A @ 125 VDC 3 A @ 30 VDC
  B200SR Electrical Ratings
External Supply Voltage
16 to 33 VDC (VFWR)
Standby Current
500 µA max.
Sound Output
Greater than 90 dBA measured in anechoic room at 10 feet, 24 volts. 85 dBA minimum in UL reverberant room
Alarm Current
35 mA max.