Velocity Addressable Heat Detectors


Key Features

  • Remote indicator output
  • Locking mechanism to avoid unauthorised removal
  • Low-profile, stylish appearance
  • Address settable from 001 to 254 by a dedicated programmer
  • Corresponds to the auto-test function of Velocity MMP control panel series


Velocity Addressable Heat Detectors are stylish and attractive, low-profile heat detectors that are designed for use with Velocity MMP fire alarm control panels. Each detector has its own unique address, assigned randomly from the factory, to provide exact detector location and their sensitivity is continually monitored and reported to the fire alarm control panel. 

These detectors incorporate a highly linear thermistor circuit that produces a voltage proportional to the temperature which is scaled and transmitted to the fire alarm control panel as a digitally encoded value. Its specially designed cover protects the detection element while allowing maximum airflow. 

Velocity Addressable Heat Detectors are available in two variants:


VDOT-H2 detectors are 8.3°C (15°F) rate-of-rise temperature heat detectors with a 57°C (134°F) fixed temperature alarm.


VDOT-H2-H detectors are the high-temperature equivalent and have a fixed temperature alarm at 83°C (181°F).


All components in the Velocity range are UL certified and comply with the requirements of Underwriters Laboratories (UL) 864 Control Units and Accessories for Fire Alarm Systems 10th Edition.

Tech Specs

Detector Element Thermistor(Negative temperature coefficient)
LED Visual IndicatorStand-by – Flashing green LED
Alarm – Solid red LED with flashing green
Operating Voltage20 VDC to 38 VDC Peak
System Voltage35 VDC
Stand-by Current200 µA
Alarm Current (with red LED)5 mA
Fixed Alarm Temperature (VDOT-H2)57°C (135°F)
Fixed Alarm Temperature (VDOT-H2-H)83°C (181.4°F)
Rate of Rise Detection (VDOT-H2)Responds to greater than 8.3°C (15°F)/min
Rate of Rise Detection (VDOT-H2-H)N/A
Operating Temperature-10°C to +55°C (14°F to 131°F)
Storage Temperature-20°C to +60°C (-4°F to 140°F)
Relative Humidity≤ RH 95 % non-condensing
Addressing MethodSoft addressing, Non-Volatile EEPROM
Address1 to 254 (decimal)
Maximum Quantity Per Loop254 units
Dimensions (W x H)104mm x 42 mm (Detector head only)
104mm x 57 mm (Detector head and VDOT-UB4 Base)
Weight100 g (Detector head only) 165 g (Detector head and VDOT-UB4)