Term
Abbreviation
Explanation
Pulse width
modulation
PWM
Terminals with an output that uses variable pulse widths, and behaves as an analogue
output.
PNP
A type of transistor.
Rack
An aluminium box with a rack system that houses the hardware modules. Each
controller consists of a rack and a number of hardware modules.
Rapid spanning tree
protocol
RSTP
A protocol used to compute the topology of a local area network.
Reactive power
Q
The 3-phase reactive power, measured in kvar.
Resistance
measurement input
RMI
Variable resistance device, used for some of the input terminals on genset controllers.
Root mean squared
RMS
Refers to the mean magnitude of a sinusoidal wave. For example, RMS V refers to the
mean AC voltage.
Running
A genset is regarded as running if the engine is started and there is running detection. A
running engine does not necessarily have to be synchronised with the busbar.
SD card
External memory
Section
Part of the busbar that is isolated from the rest of the busbar because bus tie breaker(s)
are open. Busbar sections can run independently of each other, and do not have to be
synchronised.
SEMI mode
A controller operating mode. Operator commands (for example, close breaker) start pre-
programmed sequences in the controller. Apart from trips, the controller does not
automatically open or close breakers or start or stop equipment.
Shaft generator
SG
A generator installed on the ship's main shaft that produces electricity.
Shaft generator
breaker
SGB
The breaker between the shaft generator and the main busbar/switchboard. A SHAFT
generator controller can control a shaft generator breaker.
SHAFT generator
controller
Controls and protects the power supply from the shaft generator.
Shelve
A temporary state that an alarm can be assigned to by an operator. Shelved alarms are
inactive alarms, but only for a selected period by the operator. When the period of time
expires, the alarm is automatically unshelved by the system restoring the alarm to the
previous alarm state. Alarm conditions are checked again.
Shielded foiled twisted
pair
SFTP
SFTP cables are used to minimise electromagnetic interference.
Shore connection
SC
The ship is supplied with electricity from land while in harbour through the shore
connection.
Shore connection
breaker
SCB
The breaker between the shore connection and the main busbar/switchboard. A SHORE
connection controller can control a shore connection breaker.
SHORE connection
controller
Controls and protects the power supply from the shore connection.
Shutdown
An emergency or fast stop of the genset engine. No cooldown time is allowed.
Single-phase
A system where the load is connected between one phase and the neutral. Note:
Single-phase does NOT mean a 3-wire single-phase distribution system, where the
waveforms are offset by a half-cycle (180 degrees) from the neutral wire.
[Source]
The source side of the breaker. For GENSET, EMERGENCY genset, and SHAFT
generator controllers, this is the generator. For a SHORE connection controller, this is
the shore connection. For a BUS TIE breaker controller, this is Busbar A.
Supervision
A PICUS function to monitor the operation of the entire system, and to send commands
to any of the controllers.
DESIGNER'S HANDBOOK 4189340911K UK
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