The Hochiki SPC-24 is a projected beam smoke detector for large open spaces. Specifically, it consists of an emitter and a receiver that span up to 328 feet across a room. As a result, one detector pair can cover 60 feet of linear protection on either side of the beam. This makes the SPC-24 ideal for atriums, warehouses, and gymnasiums where spot detectors are impractical.
Verified Specifications
- Type: Projected beam smoke detector (separate emitter and receiver)
- Rated voltage: 24 VDC (operating range 19-33 VDC)
- Beam range: 32.8 ft to 328 ft (10 to 100 m)
- Linear protection: 60 ft on center, per NFPA spacing rules
- Supervisory current: 50 µA (emitter), 200 µA (receiver) at 24 VDC
- Alarm current: 20 mA at 24 VDC (receiver)
- Trouble current: 20 mA at 24 VDC (receiver)
- Sensitivity (field adjustable per span): 25%, 50%, or 70% obscuration
- Alarm contacts: Form A; Trouble contacts: Form B
- Drift compensation: +1% per hour automatic, until 50% accumulated change
- Misalignment tolerance: emitter ±0.5°, receiver ±1.0°
- Dimensions: 3.2″ W x 5.5″ H x 4.0″ D each unit
- Mounting: wall mount or single gang box
- Operating temperature: 14°F to 122°F (-10°C to 50°C)
- UL installation temperature: 32°F to 100°F (0°C to 38°C)
- Maximum humidity: 95% RH non-condensing
- Approval: California State Fire Marshal 7260-0410:172
- Product code: 0200-03460
How the SPC-24 Works
The emitter generates a pulsed near-infrared beam. Then, the receiver photodiode converts the beam into an electrical signal. A microprocessor stores the initial beam intensity as the reference. Subsequently, it compares each new sample against the reference. When smoke decreases the signal beyond the selected obscuration threshold, the receiver generates an alarm.
Additionally, the receiver compensates for slow contamination of the optics. Specifically, it pulls the signal back toward the reference at about 1% per hour. However, if accumulated change exceeds 50%, the receiver generates a trouble signal so the optics can be cleaned.
Typical Applications
Projected beam detectors are specified where conventional spot smoke detectors are impractical. For example, atriums, churches, theaters, gymnasiums, factories, warehouses, museums, tunnels, and high-air-velocity areas all benefit from beam detection. As a result, one beam pair can replace dozens of spot detectors in a large open volume.
Installation Notes
Install per the SPC-24 instruction guide and applicable NFPA Standards. Specifically, NFPA 72 governs spacing, irregular ceiling surfaces, and design considerations. In addition, the receiver requires an EOLR-24 end-of-line relay for power supervision when used in four-wire installations. The SPC-24 is not listed for outdoor use.
Order or Get Application Help
Life Safety Consultants has stocked Hochiki SPC beam detectors since 2002. To order the Hochiki SPC-24 or get application help for a large-volume detection job, call 1-888-557-0558. Alternatively, email sales@lifesafetycom.com.
For more information, contact the Life Safety Consultants team at (888) 557-0558, or email us at: sales@lifesafetycom.com
Additional information
| Weight | 2.5 lbs |
|---|---|
| Dimensions | 8 × 6 × 4 in |
| Condition | New |
| Manufacturers | Hochiki |
| Part Type | Detector Base |
