Appendix B: Worksheets
212
Vigilant VS1 and VS2 Technical Reference Manual
= 0.20 V/A (64 point panel)
= 0.24 V/A (250/500 point panel)
• 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 direct current (VDC). 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.
