System Sensor 2D51 Photoelectronic Low-Profile Plug-In Detector for Special Applications

Ensure early smoke detection in HVAC, duct and plenum environments with the System Sensor 2D51 photoelectronic low-profile plug-in detector. Designed for special applications where discreet, reliable monitoring is essential, this smoke detector head provides dependable photoelectric sensing across 0–4,000 FPM airflows and installs easily into a standard electrical box or B210LP base. The twist-in/twist-out head, removable cover and insect screen reduce service time, while low standby current and dual LEDs give clear status at a glance—helping facilities teams minimize downtime and maintain compliance with NFPA monitoring requirements. The 2D51 works with the D4P120 power board to enable remote testing, reset and annunciation (RTS accessories supported), making it ideal for commercial buildings, data centers and security-sensitive installations. Backed by System Sensor craftsmanship and a 3-year limited warranty, the 2D51 balances performance with practical maintenance features for integrated fire/security systems. Contact us or add to your cart to upgrade your HVAC smoke detection and enhance building surveillance and fire protection.

• Compact low-profile design mounts in ducts and plenums for discreet, space-saving HVAC smoke monitoring
• Photoelectric sensing tuned for low/no-flow air-handling (0–4,000 FPM) to deliver fast, reliable detection
• Plug-in, twist-in/twist-out head and removable insect screen enable quick cleaning and reduced maintenance downtime
• Low standby current and LED status indicators simplify power management and onsite troubleshooting
• Seamless integration with B210LP base and D4P120 power board for remote testing, annunciation and centralized monitoring