Nautel XR6, Руководство по предварительной установке

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XR6/XR3 Pre-installation Manual Accessories
Page 10-2 Issue 3.0 2009-07-15
Ac line surge protection
A surge protector panel is recommended for all equipment at the transmitter site. The surge
protection panel helps to protect the site from lightning induced voltage transients on the ac power
source or the antenna or ground system. Nautel offers an ac line surge protection panel, which is
suitable for use with the XR6/XR3 transmitter. (Various versions are available, depending on your ac
configuration and supply voltage.) However, you can use any surge protector with at least a 1,500
Joule per phase rating.
Connect the surge protector’s ground terminal directly to the station reference ground using a 10 cm
(4 in.) wide copper strap. Also connect the surge protector’s ground directly to the ac power supply
ground, the transmitter’s grounding point, and the common ground for the site. Ensure that the
common ground is isolated from any other sources of ground (for example, grounding rods not
connected to the station reference ground), to prevent lightning charges from bypassing the surge
protector and passing through the ground and into the site.
Place the surge protector as close as possible to the ac service entrance, minimizing both the physical
and electrical distance between the service entrance and the surge protector. For detailed information
about surge protection, refer to the
Nautel Site Protection Manual.
Automatic antenna transfer control unit
The automatic antenna transfer control unit is a 19-inch, rack-mountable assembly that is used in
conjunction with two Nautel AM or FM broadcast series transmitters that are to be connected in a
main/standby configuration. The control unit controls the on/off status of the transmitters by
controlling the status of their safety interlock circuits. It also controls the ac voltage applied to relays
or contactors, to determine the routing of the RF output of the on-air transmitter to the antenna. See
“Automatic switching system” on page 10-4 . The control unit allows manual or automatic switching
of the main and standby transmitters. In automatic mode, the forward power levels of both
transmitters are monitored. If the main (on-air) transmitter's RF output falls below a preset threshold
(typically 3 dB), an automatic changeover to the standby transmitter takes place. An interlock override
feature allows the operator to enable the RF output of the standby (off-air) transmitter into a dummy
load for maintenance or troubleshooting.