516.900.202

The Simplex 516.900.202 is the detector head for the 721PH conventional UL-listed optical photo-heat detector, combining photoelectric smoke sensing with thermal detection in a single unit for enhanced false alarm immunity.
It operates in low-sensitivity optical mode during normal conditions, automatically increasing sensitivity upon rapid temperature rise detection, making it ideal for areas with potential nuisance smoke sources like kitchens or garages while maintaining fast fire response.
Key Specifications
Feature
Specification
Type
Combined optical smoke + heat detector head
Heat Activation
Rate-of-rise or fixed temperature threshold
Voltage
10.5-33 VDC (2-wire conventional)
Quiescent Current
30-60 µA average
Coverage
450-900 sq ft (standard spacing)
Compatibility
4B-UL, 5B-UL bases; 2004/4007 series panels