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 189 of 240
10.8.7 Dual redundant power supply
Dual redundant AC-DC power supply unit
Part number: 45-690-0080-001
The dual redundant power supply unit is a single unit that provides the DC output requirements of the
Radar Distribution Unit.
The PSU assembly consists of two AC-DC power units and a separate PCB that provides the power
sharing diodes for the dual redundancy output. The Radar Distribution Unit is capable of running on
just one of these power supplies (see AC power loss regarding transceiver power in previous section).
As noted below, the power supply must not be operated (switched ON) on a test bench or when
electrically and mechanically disconnected from the RDU.
WARNING: High earth leakage current devices are fitted to the dual power supply. Do
not operate the power unit disconnected from the Radar Distribution Unit Chassis and
disconnected to the MISM backplane.
WARNING: Prior to commencing any maintenance procedure, users must familiarise
themselves with the health & safety warnings noted in the planned maintenance and
health and safety sections of the system handbooks.
AC supplies: Prior to carrying out any maintenance, the system must be fully isolated
and disconnected from all single and 3-phase AC supplies. See system isolation in the
planned maintenance section of the system handbook.
UPS (Uninterruptable Power Supply): Where connected, ensure that UPS supplies to
the RDU are fully isolated prior to carrying out any maintenance task on the system.
Input: 100 to 240VAC 50/60Hz full range input
Power source: PL2: GT\af DH r<s on the base of the RDU and MCB1 supply AC power to
PSU A and to the transceiver enclosure via SK5.
PL3: GT\af DH r=s on the base of the RDU and MCB2 supply AC power to
PSU B and to the transceiver enclosure via SK6 (dual systems only).
Outputs: +24.1VDC +/- 0.6V
+15VDC +/- 0.7V
-15VDC +/-0.7V
+5VDC (4.5 to 5.9VDC)
Signals: Power good and fan fail signals
Fans: The power supply is fitted with two fans that report their status to the RDU
(Good/ Fail).
In the event of a fan failure, the power unit continues to function. Failed fans
must be replaced at the earliest safe opportunity.
Spares: The power supply is a line replacement unit and contains no field serviceable
or user adjustable parts.
Repair: The unit must not be dismantled in the field as specialist equipment is
required for testing the electrical safety barriers. Circuit diagrams are not
available for the unit.