Edwards Signaling eFSA250 User Manual
Page 228
Appendix B: Worksheets
216
E-FSA64 and E-FSA250 Technical Reference Manual
• Load factor for eFSA250 panel = 0.24 V/A
• Power type = FWR
The source voltage is the theoretical operating minimum for the power supply,
and is calculated as 85% of 24 volts.
The load factor is a measure of how the power supply voltage reacts when a load
is applied. The load factor measures the voltage drop per ampere of current
drawn by the load.
The power type reflects the type of power supplied to the NAC terminals at
minimum voltage. The current draw of notification appliances can vary
substantially with the type of power supplied: full-wave rectified (VFWR) or
regulated and filtered DC (R&F). It is important to know the power type at
minimum terminal voltage.
You’ll need to calculate the following values relating to your power supply and to
the NAC circuit current. These are:
• Minimum voltage
• Voltage drop
The minimum voltage is the lowest voltage measured at the NAC terminals when
the power supply is under the maximum load for that circuit (i.e. for the
appliances that constitute the NAC.)
The voltage drop is the difference between the minimum voltage and 16 V. This
value is for use with the worksheet only.