Strobes Per Circuit Calculator

Calculate maximum number of strobe or horn-strobe appliances per NAC circuit per NFPA 72.

Input Parameters

Results

--
Max Strobes on Circuit
units
--
Max Circuit Current
A
--
Vdrop at Max Load
V
--
EOL Voltage at Max
VDC
Note: Per NFPA 72 and UL 1971, synchronized strobes flash simultaneously drawing peak current at the same instant. Always use manufacturer peak current values. Genesis, Exceder, and similar low-current strobes allow more appliances per circuit.

Reference

Wire R = 2 x Run Length x R_per_1000ft / 1000 Max Vdrop = Supply V - Min Appliance V Max Current = Max Vdrop / Wire R Max Strobes = floor(Max Current / Peak Current per Strobe) NFPA 72: Synchronized strobes draw peak current simultaneously UL 1971 listed strobes must receive minimum rated voltage.