Nautel NARF79, Installation Manual

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VX150 TO VX2 INSTALLATION MANUAL ELECTRICAL REQUIREMENTS
VERSION 0.3 2021-01-14 PAGE 1.5.3
Ac Transient Power Protection
Protect all conductors from the ac power source by connecting bi-directional surge protection devices
between each conductor and the station reference ground. Install a ferrite toroid on the ac feed
between the transmitter and the bi-directional surge protector. Pass all the conductors and ground, as a
group, a minimum of two turns, through a ferrite toroid. Ferrite toroids are provided in the transmitter’s
Ancillary Kit.
A surge protector panel containing suitably rated varistors is available from Nautel. If purchased, install
the surge protector panel close to the station reference ground, and as close as possible to the ac
service entrance.
The ac power source usually has the lowest impedance path to ground during a lightning strike and
normally carries most of the lightning-induced current away from the transmitter site. When lightning
hits the power source (for example, striking a transmission line near the transmitter site), a significant
induced current may flow towards the transmitter. The goal of lightning protection is to route the
current around the transmitter to the best available ground.
For detailed information about surge protectors and lightning protection, refer to the Lightning
Protection section of Nautels’
Recommendations for Transmitter Site Preparation Manual
.
Station Reference Ground
Install a station reference ground that provides a continuous, low impedance path to the earth.
If a surge protector is not being used, connect the transmitter's designated safety ground point, the
shield of the coaxial feedline, and the ground connection of the power source directly to the station
reference ground using a low-impedance copper conductor (minimum 3/4” braid, 4-inch strap, or
0 AWG wire). Ensure that the site’s ac service entrance ground is directly connected to the station
reference ground outside the transmitter building.
If a surge protector is being used, connect the transmitter's designated safety ground point, the shield
of the coaxial feedline, and the ground connection of the power source directly to the surge protector,
using a a low-impedance copper conductor (minimum 3/4” braid, 4-inch strap, or 0 AWG wire).
Connect the surge protector to the station reference ground using a similar low-impedance coper
conductor.
Ensure that the transmitter site’s grounding rods are adequate. For more information about electrical
grounding protection, see Nautel’s
Recommendations for Transmitter Site Preparation Manual
.