Nautel NX100, Руководство по предварительной установке

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NX100 Pre-installation Manual Electrical requirements
Issue 3.2 2017-03-31 Page 5-3
Recommended configuration.
Use a 4-wire Wye (star) configuration, with the three phases
balanced to ground.
Ac power switch
Install an external ac power disconnect between the ac power source and the transmitter’s
transformer. (Nautel can provide a suitable ac power disconnect, if required.) For safety, place the ac
disconnect close to the transmitter and label it
TRANSMITTER EMERGENCY ON/OFF SWITCH
.
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. In addition, pass all the
conductors and ground, as a group, through a ferrite toroid. Install a ferrite toroid (Nautel Part #
LX63, located in the ancillary kit) on the ac feed between the transmitter and the bi-directional surge
protector.)
A surge protector panel containing suitably rated varistors is available from Nautel. 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 Nautel’s
Recommendations for Transmitter Site Preparation Manual.
CAUTION:
Do NOT use open delta three-phase ac power sources that use two identical
transformers. These systems are susceptible to third harmonic distortion
and line transients, and may cause peak voltages to exceed the line
voltage. This can cause increased power supply noise or even component
failure (for example, rectifier failure).