User's Manual

SBS-900 Shore Based Radar Systems
Chapter 10: Corrective maintenance
KH-1602-2 issue 1: Standard SBS900 Systems Operator & Maintenance Handbook
Page 122 of 240
10.2 Standard systems overview
10.2.1 Power connections
AC/ DC
power:
RDU: Two sources of UPS supported single phase AC and a separate
three phase supply are connected to the RDU.
Internal breakers and contactors control the AC voltages to the rest
of the system.
An internal power supply generates all the DC rails required by the
RDU.
Transceiver
Enclosure
Single or dual (system dependent) sources of AC power are
connected from the RDU and are internally protected and switched
by the use of breakers.
Internal power supplies generate all the DC rails required by the
transceiver enclosure.
A separate DC rail is provided to power the ACP/ ARP encoder in the
antenna sub-system.
Antenna sub-
system
The antenna motor is driven by the three phase output of the RDU
(see below).
A DC rail from the transceiver Enclosure is used to power the ACP/
ARP encoder.
Three phase measurement: The three phase output of the inverter is a pulse width modulated
(PWM) sine wave which cannot be accurately measured using a
standard DVM (Digital voltmeter).
If measured the 440VAC output will actually measure approximately
220VAC +/-10% depending on the multimeter being used.
10.2.2 Over current protection devices
Kelvin Hughes gearboxes: There are no fuses or breakers located within the gearbox for the AC
supplies to the Kelvin Hughes gearbox.
The safety mechanisms within the Radar Distribution unit and
transceivers which include the Man Aloft Switch and Antenna
Rotation keyswitch should be used to isolate the system.
See section 9.3 page 87 onwards for full details.