The Fire Protection and Research Foundation (FPRF) found that “a square-wave sound with a fundamental frequency in the lower ranges (i.e. 520 Hz) to be more effective than the current high pitched smoke signal across a range of populations”. The NATIONAL TIME low frequency signaling device is designed to meet the newly adopted NFPA 72 sleeping space requirements of a 520 Hz square-wave tone based upon these findings. The signal pattern can be temporal 3 or temporal 4 output to meet future carbon monoxide signaling requirements.
These SG-LF Series signals achieve the industry’s highest dBA levels (even on its normal level setting) while remaining the lowest current draw. This provides better coverage and fewer devices in some installations.
The aesthetically pleasing design (available in red or off-white) did not compromise the ease of installation that you have become accustomed to with National Time signaling devices. The universal mounting plate can be mounted on a wall or ceiling using a single gang, double gang, double workbox, 3.5” round, or 4-square electrical boxes. The sliding mounting bracket allows the installer to pre-wire the system, test for system supervision, and remove the signal head until occupancy. Furthermore, there is volt meter access to the wiring terminals when the device is installed to make it simple to
confirm end of line voltages.