The System Sensor HR-LF is a 2-wire, red low-frequency sounder. It produces a 520 Hz ± 10% square-wave tone for fire alarm notification.
First, NFPA 72 requires a 520 Hz low-frequency signal in sleeping areas of commercial buildings built since 2014. Then the HR-LF satisfies that requirement using a single NAC pair. As a result, retrofits can add code-compliant sleeping-area notification without rewiring the SLC.
Why a 520 Hz Tone
Research shows the 520 Hz square-wave tone wakes sleeping adults more reliably than the older 3 kHz alarm tone. In addition, the lower frequency carries better through doors, walls, and bedding. Therefore the HR-LF is well suited for hotel guestrooms, dormitories, multi-family residential, and assisted-living suites.
System Sensor HR-LF Key Features
- 520 Hz ± 10% square-wave tone
- 2-wire notification appliance circuit operation
- Nominal 12 or 24 VDC operation, auto-selected
- ≥ 75 dBA at pillow level
- Plug-in design — minimal intrusion into the back box
- Listed to UL 464 for fire protective service
- Compatible with built-in NAC sync from common FACP brands
Order or Get Application Help
Since 2002, Life Safety Consultants has been a trusted source for System Sensor notification appliances. To order the System Sensor HR-LF or get application guidance, call 1-888-557-0558. You can also 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 | 2.14 lbs |
|---|---|
| Dimensions | 2 × 4.7 × 5.6 in |
| Condition | New |
| Manufacturers | System Sensor |
| Part Type | Sensor |
