Nautel VS300, Руководство по предварительной установке, Страница: 30 / 62

VS300 Pre-installation Manual Electrical requirements
Page 5-2 Issue 2.0 2010-12-01
Table 5.1: VS300 Input power requirements
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 (part # NAX188).
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.
Mode of
operation
Input
power
(VA)
Ac supply
(vac)
Maximum line
current (A)
(low line)
Maximum
inrush current
per line (A)
FM (analog)
Worst-case eff. =
58%
569 1-Ph, 180 - 264 3.2 12.7
1-Ph, 90 - 132 6.2 24.7
Maximum line current values are based on maximum RF output power, minimum ac voltage (180 or 90 V ac, as
applicable) and worst-case efficiency.
The maximum inrush current value (per line) is present for half an ac cycle (between 8 and 10 ms). It is typically four
times the maximum line current and is provided to aid in planning for upstream protection.
Observe local electrical codes when determining wire size and circuit breakers.
Nautel recommends that you base your wire sizes and breaker ratings on the maximum line current for analog mode
plus a nominal 25%.