S270 Intrinsically Safe Photoelectric Smoke Detector
- Ionization type Smoke Detector with dual Stainless Steel Ionization Chambers
- BASEEFA approved for use in EEx ia IIC T5 hazardous locations
- Locking feature for tamper resistance
- FM approved for use in Class I Division 1 Groups A,B,C,D hazardous (classified) locations
- UL approved as an automatic smoke detector
- Two LED alarm indicators provide 360º visibility
- Functional Test Capability without requiring Smoke or other chemicals
- Field Sensitivity metering of detector Meets requirements of NFPA Standard 72
- Optional remote LED alarm indicator
THE DETECTOR
Intrinsically safe detectors are used in hazardous locations where explosive levels of gas or vapors are normally or potentially present. The Model S251IS circuit power levels are limited so the potential to ignite an explosive atmosphere is eliminated.
Intrinsically safe detectors must be compatible with the system control panel for proper use. An intrinsically safe barrier must be installed at the point where the intrinsically safe circuit connects to the control panel. The barrier limits the available voltage and current available on the circuit to safe levels.
The SST Model S251IS Smoke Detector is a dual chamber ionization type detector designed to respond to the first traces of a fire by sensing both visible smoke and invisible products of combustion. It is designed for smoke detection in open areas. When installed with a suitable NOVA-5000 Detection System, the Model S251IS may be used for Releasing Device Service.
The smoke detector is installed into its accessory base with a simple twist-lock action, which prevents unauthorized removal of the detector. Operating power is provided over the 2-wire detection circuit from the Control System. Proper operation of the detector is indicated by two red Light Emitting Diodes (LED), which provides a local, 360º visual indication of detector status. For installations where the detector is not visible (such as above a false ceiling), a remote LED may be connected to the unit. When the detector senses a fire, it latches into alarm and remains in this condition until reset from the NOVA-5000 System control panel.
The smoke detector is installed into its accessory base with a simple twist-lock action, which prevents unauthorized removal of the detector. Operating power is provided over the 2-wire detection circuit from the Control System. Proper operation of the detector is indicated by two red Light Emitting Diodes (LED), which provides a local, 360º visual indication of detector status. For installations where the detector is not visible (such as above a false ceiling), a remote LED may be connected to the unit. When the detector senses a fire, it latches into alarm and remains in this condition until reset from the NOVA-5000 System control panel.
Application Information
The Model S251IS Smoke Detector is intended for installation per NFPA Standard 72 on a ceiling, on a wall near the ceiling, or under a raised floor. NFPA 72 recommends Ionization Smoke Detection where flaming fires that produce invisible products of combustion are expected.
The Model S251IS is to be installed on maximum 30 foot centers, typically on smooth ceilings up to 15 feet high with minimum air circulation. This results in a 900 square foot coverage area which may be used as a guideline for coverage. Where special conditions exist (ceiling obstructions, high air exchange rates, etc.), reduced square footage spacing must be used to achieve adequate protection.
Technical Specifications and Ordering Information
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TECHNICAL SPECIFICATIONS
| Detection Method: | Dual ionization Chambers Includes sealed radioactive source. |
| Operating Voltage: | 15 to 28 VDC Provided by the SST NOVA-5000 Control System. |
| Operating Environment: | +32 to +120°F, 0 to +49°C for UL/FM installations -10 to +60°C, +14 to 140°F for BASEEFA/LPCB installations 10 to 93% relative humidity Humidity should be below the dew point (non-condensing). |
| Intrinsic Safety Rating: | EEx ia IIC T5 Class I, Div. 1, Groups A,B,C,D |
| Size/Weight: | 4.0 inches diameter x 1.66 inches high, 3.5 ounces |
ORDERING INFORMATION
| PART NUMBER | DESCRIPTION |
| 251-01 | Model S251IS Intrinsically Safe Ionization Smoke Detector Requires mounting base for installation. |
| 280-12 | Intrinsically Safe Mounting Base Installs on US standard 3 to 4 inch round, square or octagonal wiring box. Provides twistlock plug-in for detector. |
| 289-02 | Intrinsically Safe Barrier Use to connect intrinsically safe field circuits to SST Model 5010 Smoke/ Fire Detection Module. |
| 288-98 | Remote Alarm Indicator Mounts on US standard single gang outlet box. |
| 290-01 | Functional Test Magnet Simulates the effects of smoke to test alarm capability of detector. |
