System Sensor D4120 4-Wire Photoelectric Duct Smoke Detector

System Sensor D4120 Duct Smoke Detector

The System Sensor D4120 is a commercial 4-wire photoelectric duct smoke detector designed for HVAC duct applications where smoke detection and equipment shutdown/control functions are required.

Key Features

• 4-wire photoelectric duct smoke detector
• Integrated low-flow technology
• Air velocity range: 100 to 4,000 ft/min
• 24 VAC/DC or 120 VAC power
• Two DPDT Form-C relay contacts for fan shutdown and auxiliary control
• Built-in Test/Reset button
• LED status indication
• Interconnect capability for multi-fan shutdown
• Plug-in sensor head for service and maintenance
• Compatible with System Sensor InnovairFlex accessories
• UL listed and FM approved

HVAC Shutdown Applications

The D4120 includes auxiliary relay contacts that can be used for HVAC fan shutdown and related control functions when designed and wired for the specific equipment and approved sequence of operation. Duct detector shutdown wiring should be coordinated with the HVAC equipment, fire alarm system, electrical controls and applicable code requirements.

Commercial Fire Alarm Service in Austin

Security Tekton / Avenger Security provides duct detector replacement, troubleshooting, fire alarm monitoring, HVAC shutdown verification and commercial fire alarm service throughout Austin, Round Rock, Georgetown, Cedar Park, Pflugerville, Hutto and Central Texas.

Manufacturer: System Sensor
Model: D4120
Detection: Photoelectric
Wiring: 4-wire
Power: 24 VAC/DC or 120 VAC
Air Velocity: 100–4,000 ft/min
Relay Outputs: Two DPDT Form-C
Application: HVAC duct smoke detection and fan shutdown/control

Important: A duct smoke detector is not a substitute for open-area smoke detection or the building's required fire alarm detection system. Final installation, wiring, shutdown sequence and testing must follow the approved design, equipment instructions and applicable AHJ requirements.