Installation Guide

Table Of Contents
should be grounded using its own ground rod. This reduces any neutral currents that might flow
in the site ground system.
Warning! If the transformer is located near the building, connect the transformer
ground directly to the BGR.
Cable Entrance Facilities
The MGB must be used for the single reference ground for all interior grounds.
Grounding Cable Entrance Facilities
1. Install a copper entrance TVSS at the entrance of the copper cable into the building space.
2. Bond all shielded cabling entering the building envelope to the MGB as soon as it enters the
building. Ideally, these cables need to enter near (within three feet) of the MGB.
Note: For all dielectric fiber cables, there is no requirement for bonding to the MGB, and
therefore, no requirements for these cables to enter within 3 feet of the MGB.
3. Bond the sheaths of the copper phone cables, fiber cables, and coax cables to the MGB.
4. If the cable entrance is a distance away, then install and bond a separate terminal
Fiber/Copper Ground Bar (FCGB).
5. The shields of all low voltage shielded control cable, where the cable is connected to a device
outside the building and to a controller inside the building, must be grounded at the device
outside the building.
6. Install a TVSS for all cables (including copper and low voltage shielded control cables)
entering the building.
7. Ground the TVSS to the MGB if it is within a short distance.
8. If the TVSS is a distance from the MGB, bond it to earth (for example, building steel or
dedicated ground rod).
Note: Any conductor in a continuous grounded metal conduit does not require a TVSS
be installed.
Clamp-On Ground Resistance Testing
A clamp-on ground resistance tester measures ground rod and small ground grid resistance
without the use of auxiliary ground rods. Clamp-on ground resistance testers are used in multi-
grounded systems without disconnecting the ground under test and with electrical service
connected.
23 June 2020 TDC-0971-012 Itron, Inc. Page 129 of 134
CCU 100 and Repeater 100 Installation Guide F Grounding Specifications