Specifications

Section 3: Installation Planning
3-13
for the VIPs for a total of 12. The distance to the last device is 1200 feet. Looking at the row for
15 loads and the column for 1500 feet; the required wire size for this S-Net power pair is 16 AWG.
3.6.3 ALTERNATIVES TO LARGE POWER WIRE
If the wire size from the table is very large, there are alternatives:
1. A second power supply can be located closer to the devices to limit the total length.
2. Two or more conductor pairs can be used to increase the load capacity.
2-26 AWG ≈ 1-22 AWG
2-20 AWG ≈ 1-18 AWG
2-18 AWG ≈ 1-16 AWG
If the size gets too large to fit into the compression terminal blocks then a splice can be made
from 16 awg to the required larger wire.
NOTE:
The communication pair does not need to duplicate the power pair size. The data pair should
remain a twisted shielded pair of 22 or 24 awg.
3.6.4 FUTURE SYSTEM EXPANSION
Keep in mind that the wire size chosen for the installation must accommodate future system
growth. If more doors are to be monitored in the future, consider the alternatives:
 Use larger wire to accommodate the additions, or
 Plan to add a power supply for the new doors.
3.6.5 S-NET CABLE
The S-Net cable is generally described as two twisted pairs with an overall shield (one pair for
power and one pair for communication). When separate power and communications cables are
used, attach the shields together.