Kidde VS1 - RZI16-2 24 V in Riser Maximum Wire Run Calculation

Appendix B: Worksheets
202 P/N 3102351-EN • REV 005 • ISS 28DEC18
RZI16-2 24V IN riser maximum wire run calculation
Use the APS/BPS notification appliance circuit calculation in the Remote Booster Power
Supply Manual (P/N 3100485-EN) to calculate maximum wire run distance for RZI16-2 NAC
circuits.
RZI16-2 24V IN cable length
VS1 AUX1 VS4 AUX1 APS/BPS
Maximum RZI16
-2 alarm current
0.85
0.85 1
A
Load factor
× 0.20 0.24 0.59
Alarm current voltage drop
=
0.17
0.20 0.59
V
Source minimum voltage
20.40 20.40 19.10 V
Load voltage drop
−
0.17
0.20 0.59
V
Minimum source output voltage
=
20.23
20.20 18.51
V
RZI16
-2 minimum input voltage − 18.40 18.40 18.40 V
Voltage drop [1]
=
1.83
1.80 0.11
V
Total operating current
÷ 0.85 0.85 1 A
Maximum wire resistance
= 2.15 2.21 0.11 Ω
Wire resistance (Ω/ft) [2]
÷
0.00198
0.00198 0.00198
Maximum single wire length
= 1, 087 1, 142 55 ft.
÷
2
2 2
Maximum 2
-wire cable
length[3]
=
543
535 27.5
ft.
[1] This voltage drop is valid for regulated notification appliances only.
[2] For example, the value shown is typical resistance for 12 AWG 7-strand wire. Use the manufacturer’s
published wire resistance expressed in ohms per foot. For other typical values, see Table 46 on page 197.
[3] The value shown is for the VS4 panel. Maximum RZI16-2 24V IN riser cable distance length shown is based
on using 12 AWG, 7-strand conductor cable.