ProSoft Technology BM GM1K Series, User Manual

Page: 21 / 101

Wiring Diagrams (Serial and Power)
ProSoft Technology, Inc. Page 21 of 101
January 8, 2018
4.3 Grounding Gateways

Battery negative should never be common with earth ground.

For fiberglass enclosures, the backplane inside may be connected to earth
ground. Typically, there is a lug specifically for this connection. The
equipment inside the enclosure however, should not be common with the
backplane in this case.

For steel enclosures, battery negative should not be common with the
enclosure as the enclosure will usually be common with the pole supporting it
(basically earth ground).
A. Where bulkhead (black phantom) antennas are used, the inner surface, outer
surface, and inner wall of the hole drilled, should be isolated from the
antenna. Use the rubber washers supplied by the manufacturer to isolate the
antennas from the enclosures (use thickest washer on exterior side of
enclosure).
B. Where external antennas, such as omni-directional and yagi, are utilized, a
polyphaser is typically used. The actual connection between lightening
arrestor and antenna cable should be isolated. The lightening arrestor itself
has its own lug designed to be connected to earth ground.

Once all wiring and grounding recommendations have been followed
it is important to test the ground resistance at the grounding rod to
assure a good ground. The most effective grounding method is direct
connection to earth ground with minimal impedance. An impedance of
less than 5 Ohms is recommended.

For more details on proper grounding electrodes and grounding
electrode conductors, consult the National Electrical Code.
CAUTION: Ensure field wiring connections are in accordance with Article 504 of the National Electrical
Code, ANSI/NFPA70. For more details on proper grounding electrodes and grounding electrode conductors,
consult the National Electrical Code.