The four zone SK-4/E is a 24 VDC
FACP that provides four Class B
initiating device circuits and two Class
B notification appliance circuit (NAC).
The SK-4/E NAC protocol includes the
ability to silence audible devices while
strobes continue to flash, using only a
single pair of wires. The SK-4/E is also
compatible with conventional input
devices such as two- and four-wire
smoke detectors, pull stations,
waterflow devices, tamper switches and
other normally-open contact devices.
Activation of a compatible smoke
detector or any normally-open fire
alarm initiating device activates audible
and visual signaling devices, illuminates
an indicating LED, sounds the piezo
sounder at the FACP, activates the
FACP alarm relay, and operates an
optional module used to notify a remote
station or initiate an auxiliary control
function.