NOTIFIER FSP-851 — a low-profile intelligent plug-in photoelectric smoke detector with integral communication, compatible with NOTIFIER ONYX and CLIP series Fire Alarm Control Panels.
Detector sensitivity can be programmed in the control panel software, and sensitivity is continuously monitored and reported to the panel. Point ID capability allows each detector’s address to be set with rotary, decimal address switches, providing exact detector location for selective maintenance when chamber contamination reaches an unacceptable level. The FSP-851 photoelectric detector’s unique optical sensing chamber is engineered to sense smoke produced by a wide range of combustion sources.
FlashScan® (U.S. Patent 5,539,389) is a communication protocol developed by NOTIFIER that greatly increases the speed of communication between analog intelligent devices. Intelligent devices communicate in a grouped fashion; if one of the devices in the group has new information, the panel’s CPU stops the group poll and concentrates on single points, giving response speed greater than five times that of earlier designs.
The FSP-851 is a plug-in head that uses a separate base to simplify installation, service and maintenance — the base is ordered separately. A special tool allows maintenance personnel to plug in and remove detectors without using a ladder. The FSP-951 Series is the current direct replacement for the FSP-851 Series, but the 851 remains widely used for service and replacement in existing systems.
Specifications
| Sensing technology |
Photoelectric |
| Sensitivity |
0.5% to 2.35% per foot obscuration |
| Voltage range |
15 – 32 volts DC peak |
| Standby current (max. avg.) |
300 µA @ 24 VDC (one communication every five seconds with LED enabled) |
| LED current (max.) |
6.5 mA @ 24 VDC ("ON") |
| SLC connection |
Two-wire; compatible with FlashScan® and CLIP protocol systems |
| Addressing |
Rotary, decimal — 1–99 on CLIP systems, 1–159 on FlashScan systems |
| Height |
2.1" (5.3 cm); base determines diameter |
| Diameter with B210LP(A) base |
6.1" (15.5 cm) |
| Diameter with B501(A) base |
4.1" (10.4 cm) |
| Diameter with B200S(A) / B200SR(A) base |
6.875" (17.46 cm) |
| Diameter with B224RB(A) / B224BI(A) base |
6.2" (15.748 cm) |
| Shipping weight |
5.2 oz. (147 g) |
| Operating temperature range |
32°F to 120°F (0°C to 49°C) |
| Relative humidity |
10% – 93% non-condensing |
| UL/ULC listed velocity range |
0 – 4000 ft./min. (1219.2 m/min.), suitable for installation in ducts |
| Housing |
Off-white fire-resistant plastic, 94-5V flammability rating |
| UL listed |
S1115 |
| ULC listed |
S1115 (FSP-851A, FSP-851RA, FSP-851TA) |
| FM |
Approved |
| CSFM |
7272-0028:0206 |
| MEA |
225-02-E |
| Maryland State Fire Marshal |
Permit # 2122 |
Installation notes
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Base is a separate order: the FSP-851 must be mounted to a compatible base — B210LP(A), B501(A), B200S(A), B200SR(A), B224RB(A) relay or B224BI(A) isolator. For base details see DN-60054.
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Backbox depth: mount the base on an electrical backbox at least 1.5" (3.81 cm) deep.
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Wiring: end-of-line resistors are not required because of the inherent supervision provided by the SLC loop. T-taps or branches are permitted for Style 4 (Class B) wiring.
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Isolator limits: when using relay or sounder bases, consult ISO-X(A) installation sheet I56-1380 for device limitations between isolator modules and isolator bases. A maximum of 25 devices is allowed between B224BI(A) isolator bases.
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Addressing ceiling differs by protocol: 1–99 on CLIP systems but 1–159 on FlashScan — confirm the loop protocol before assigning addresses above 99.
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Standby current is higher than the 951: at 300 µA versus 200 µA, loop current budgets calculated for FSP-951 detectors do not transfer directly when retrofitting 851 heads.
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Relay base ratings (B224RB(A)): Form-C, 2.0 A @ 30 VDC resistive; 0.3 A @ 110 VDC inductive; 1.0 A @ 30 VDC inductive.
Related models
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FSP-851A — same detector with ULC listing.
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FSP-851T / FSP-851TA — adds a built-in 135°F (57°C) fixed-temperature thermal device; operating range narrows to 32°F to 100°F (0°C to 38°C), with a low temperature signal at 45°F ± 10°F.
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FSP-851R / FSP-851RA — remote test capable for DNR(A)/DNRW duct housings; rated -4°F to 158°F (-20°C to 70°C) when installed in the housing.
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FSP-951 — the current-generation replacement, with a 2.0" profile, 200 µA standby current and UL 268 7th Edition design.
Specifications taken from the NOTIFIER data sheet "FSP-851(A) Series Intelligent Plug-In Photoelectric Smoke Detectors with FlashScan," document DN-6935:E (2/11/2015). Manufacturer specifications are subject to change without notice.
