Maintenance Handbook

SBS-800 Series Operator & Planned Maintenance Handbook
Chapter 4: Switch ON, OFF & Emergency Stop
KH-1601-2 Issue 6
Page 31 of 80
4.5 System Isolation
In addition to the normal health and safety requirements, the system must be made safe prior to
carrying out any maintenance task by fully isolating and locking OFF all AC power including any UPS
supported supplies to the system and where connected the Anti-Condensation Heater (ACH) supply
as shown below:
RDU
Antenna
rotation
keyswitch
Place the Antenna Rotation keyswitch on the front of
the Radar Distribution Unit into the OFF position.
The key should be removed and retained until the
maintenance task being undertaken has been
completed.
Man aloft
switch
(MAS)
As an additional safety precaution, the Man Aloft
Switch can be placed into the OFF position.
This acts as a backup safety measure to removing the
Antenna Rotation keyswitch.
RDU
AC power
Within the Radar Distribution Unit, ensure all
breakers are in the OFF position.
Note: When switched OFF, the LED’s on each
breaker remain illuminated indicating that AC
supplies are still connected to the RDU.
External AC
Supplies
The external AC supplies to the system consist of:
 2 x System supplies: Two UPS supported single phase AC supplies to the
Radar Distribution Unit.
 1 x Motor Supply: A single AC antenna motor supply to the Radar Distribution
Unit. Depending on the system, this may be a single or three phase supply.
 1 x ACH supply: A single phase AC supply from a dedicated breaker
supplying the anti-condensation heaters located within the transceiver/gearbox
assembly.
Isolate and disconnect ALL AC supplies to the Radar Distribution Unit and
Transceiver/Gearbox Assembly including all UPS supported supplies.
Physically remove all breaker sockets or lock the breakers into the OFF position.
Ensure that suitable signs are in place indicating that the system is isolated.
WARNING
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.
WHEN CONFIGURED AS DETAILED ABOVE, THE SYSTEM IS ISOLATED FROM ALL SOURCES
OF AC SUPPLY