Kidde VM-1 Technical Reference Manual

Appendix A: System calculations
P/N 3101890-EN • REV 006 • ISS 21JUN18 183
Table 75: Maximum allowable length at 70 VRMS, 0.5 dB loss
Circuit load requirement
Wire size
15 W 20 W 30 W 40 W 95 W 120 W
ft m ft m ft m ft m ft m ft m
18 AWG
(0.75 sq mm)
1489 454 1117 340 744 227 558 170 235 72 186 57
16 AWG
(1.0 sq mm)
2420 738 1815 553 1210 369 907 276 382 116 302 92
14 AWG
(1.5 sq mm)
3722 1134 2792 851 1861 567 1396 426 588.7 180 465 142
12 AWG
(
2.5 sq mm)
6049 1844 4537 1383 3024 922 2268 691 955 291 756 230
Cabinet battery
Use the following method to calculate the minimum ampere-hour capacity of a battery required in order to operate
a panel in the absence of AC power. Battery calculations must be performed separately for each cabinet in the
system.
Determine the total amount of current in milliamps required by all of the components that derive power from the
battery while the panel is in standby mode. Multiply the total amount of standby current by the number of hours
that the panel is required to operate in standby mode while on battery power.
Determine the total amount of current in milliamps required by all of the components that derive power from the
battery while the panel is in alarm mode. Multiply the total amount of alarm current by the number of minutes that
the panel is required to operate in alarm mode while on battery power. Divide the result by 60 to convert minutes
to hours.
Add the total amount of standby current and the total amount of alarm current then divide the result by 1000 to
convert to ampere-hours. Multiply this number by 1.2 to add a 20% safety factor to the calculations.

Kidde VM-1 Specifications

General

Brand	Kidde
Model	VM-1
Category	Fire Alarms
Language	English