Edwards Signaling EBPS Remote Booster Power Supply - Manual (Page 45)

Remote Booster Power Supply Technical Reference Manual 39
Worksheet method
Use this worksheet to determine the maximum cable length of a notification
appliance circuit for a given number of appliances.
Use this worksheet only if all the appliances are regulated. That is, they must
have a minimum operating voltage of 16 V. For other appliances, use the
“Equation method.”
Worksheet 1: NAC cable length
NAC1 NAC2 NAC3 NAC4
Total operating current [1] A
Load factor × 0.59 0.59 0.59 0.59 V/A
Load voltage drop = V
Source voltage 19.1 19.1 19.1 19.1 V
Load voltage drop − V
Minimum voltage = V
Regulated appliance voltage − 16.0 16.0 16.0 16.0 V
Voltage drop [2] = V
Total operating current  A
Maximum resistance = Ω
Wire resistance (Ω/ft) [3] 
Maximum wire length = ft
 2 2 2 2
Maximum cable length = ft
[1] Total of the maximum operating currents for all appliances as specified for DC power. See
the appliance installation sheets for operating currents.
[2] This voltage drop is valid for regulated notification appliances only. For special application
appliances, see “Equation method,” later in this topic.
[3] Use the manufacturer’s published wire resistance expressed in ohms per foot. For typical
values, see Table 11 on page 40.