Specifications

Alto 818 Installation and Operation
3-12 P/N 66109074001 Rev. D
3.6.2 S-NET POWER WIRE SIZE
The daisychaining of S-Net devices causes significant cable losses. At least 16 volts must be
available at each node to insure proper operation. The following steps will help determine the
proper wire gauge for an installation.
1. Find the total number of load units from the Device Load Table below. Add only the devices
on the S-Net that are at least 50 feet (15 meters) from the power supply.
Table 3-5: S-Net Device Load
Device Load Units
DR 4204 2 Each
DR 4205 2 Each
DR 4208 4 Each
DR 4226 8 Each
DR 4238 10 Each
VIP2 1 Each
Ma
g
stri
p
e
(
MS R
)
1 Each
2. Using the Power Wire Size table below, the cable gauge is the intersection of the row
containing the accumulated number of loads and the column with the S-Net length.
Table 3-6: Power Wire Size
Distance
Load Units 500 Ft 750 Ft 1000 Ft 1500 Ft 2000 Ft 3000 Ft 4000 Ft
5 24 AWG 22 AWG 22 AWG 20 AWG 18 AWG 16 AWG 16 AWG
10 22 AWG 20 AWG 18 AWG 16 AWG 16 AWG 14 AWG 12AWG
15 20 AWG 18 AWG 16 AWG 16 AWG 14 AWG 12 AWG 10 AWG
20 18 AWG 16 AWG 16 AWG 14 AWG 12 AWG 10 AWG 8 AWG
25 18 AWG 16 AWG 14 AWG 12 AWG 12 AWG 10 AWG 8 AWG
30 16 AWG 14 AWG 14 AWG 12 AWG 10 AWG 8 AWG
35 16 AWG 14 AWG 14 AWG 12 AWG 10 AWG 8 AWG
40 16 AWG 14 AWG 12 AWG 8 AWG 8 AWG
An example system might contain the following S-Net devices: 1 Alto 818 ACU, 4 DR 4205
DigiReaders, and 4 VIPs. The loads are loads are: 4 X 2 = 8 for the DR 4205s and 4 X 1 = 4