Installation Guide

TP-6879 3/15 23Section 1 Installation
1.10.2 Communication Cable
Specifications
RBUS Connections A and B
For the RBUS communication connections A and B to
the Model RXT transfer switch, optional PIM and/or
optional LCM or load shed kit, use 20 AWG shielded,
twisted-pair communication cable. Belden #9402
(two-pair) or Belden #8762 (single-pair) or equivalent
cable is recommended.
For outdoor installations, including those with buried
cables and/or conduit, use outdoor-rated Belden
#1075A or equivalent 20 AWG shielded, twisted-pair
communication cable.
PWR and COM Connections
For the PWR and COM connections from the generator
set to the RXT, PIM and/or LCM or load shed kit, use the
second pair in the two-pair communication cable for
short runs, or use 12--14 AWG cable for longer runs as
shown in Figure 1-21.
The maximum cable length depends on the number of
optional modules connected. A module can be a Model
RXT transfer switch, a load control module (LCM) or a
load shed kit or a programmable interface module
(PIM). See Figure 1-21 for the maximum cable lengths
with 1, 2, or 3 modules per cable run. Note the shield
connections shown in Figure 1-23.
Cable Size for PWR and COM Connections
Indoor or
Outdoor
Installation
Maximum length per run, meters (ft.)
Number of Modules (ATS, PIM and LCM, or Load
Shed Kit
)perRun
1 Module 2 Modules 3 Modules
20 AWG Belden #9402 or equivalent, two-pair Indoor
61 (200) 31 (100) 21 (67)
20 AWG Belden #1075A or equivalent, two-pair Outdoor
61 (200) 31 (100) 21 (67)
14 AWG * —
152 (500) 152 (500) 122 (400)
12 AWG * —
152 (500) 152 (500) 152 (500)
* Use 12 or 14 AWG cable for PWR and COM connections only. For RBUS connections A and B, use shielded, twisted pair communication
cable specified in Section 1.10.2.
Figure 1-21 Total Cable Lengths for PWR and COM Connections