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Extended Operational and Trade Vocabulary

Marine Electrical Systems and Shore Power glossary (page 2)

The marine-electrical vocabulary: the ABB Azipod podded-propulsor range (D, ICE, M, XO) and the Dynafin concept, high-voltage distribution, shore connection for cold ironing, and the power-management and propulsion-drive terms. Grounds each term in the electrical system or the propulsion product it belongs to.

319 defined terms.

Showing 69 on this page (page 2 of 2).

S

Short Circuit Calculation
Engineering analysis to IEC 61363-1 determining prospective fault currents on a marine bus.
Siemens 3WL
Air circuit breaker family from Siemens used on marine LV main switchboards.
Siemens 8DA10
Single-busbar gas-insulated medium-voltage switchgear from Siemens used on cruise ships and offshore vessels.
Siemens BlueDrive PlusC
Diesel-electric and hybrid propulsion package from Siemens Energy Marine.
Siemens NXAir
Air-insulated medium-voltage metal-clad switchgear from Siemens used on marine MV systems.
Siemens Simotics HV
High-voltage induction motor range from Siemens used in marine propulsion and large auxiliaries.
Sinusoidal Filter
Output filter on a variable frequency drive that smooths the PWM waveform to a near-sinewave.
Slip Ring
Rotating conductor that transfers current to or from a rotor winding through stationary brushes.
Solid State Soft Starter
Thyristor-based starter that ramps voltage to limit inrush current on marine motors.
Spinning reserve
Power system reserve; included for grid context.
Star Delta Starter
Reduced-voltage starter that connects motor windings in star for start, then transitions to delta.
Steerprop SP
Steerable mechanical and electric azimuth thruster from Steerprop of Rauma, Finland.
Stockholm Norvik Port Shore Power
Shore power installation at the newer Stockholm port for ro-ro and container ships.
Sub-distribution Board
Smaller distribution panel fed from a main distribution board to serve a defined area or system.
Surge Arrester
Metal oxide varistor device protecting marine equipment from voltage transients.
Switchboard
Assembly of busbars, breakers, instruments, and protection relays distributing electrical power.
Synchronizing Lamps
Three lamp arrangement used as a backup synchronization indicator on older switchboards.
Synchronous Condenser
Synchronous machine running unloaded to provide reactive power, occasionally used at large ports.
Synchronous Generator
Three-phase AC generator whose rotor rotates in synchronism with the stator field, standard for shipboard generation.
Synchroscope
Instrument indicating the phase difference between an incoming generator and the bus for manual synchronization.

T

Tap Changer
Mechanism on a transformer that selects different turns ratios to adjust output voltage.
TEFC Motor
Totally enclosed fan-cooled induction motor common in marine pump and fan applications.
THD
Total harmonic distortion, expressed as a percentage of the fundamental voltage or current.
Thermal Imaging Survey
Use of IR camera to detect hotspots on machinery or insulation.
Thermal Overload Relay
Bimetallic device protecting marine motors from sustained overcurrent.
Three Phase Four Wire System
Distribution arrangement with a distributed neutral, used in low-voltage marine lighting subsystems.
Three Phase Three Wire System
Standard ungrounded marine main bus arrangement requiring an insulation monitoring device.
Trace Heating
Resistive heating cables used to keep pipes and panels above the freezing point in marine installations.
Transformer Rectifier
Combined transformer and rectifier unit supplying DC to thrusters, drives, or shore conversion equipment.
Trip Curve
Time-current characteristic defining when a breaker or fuse will operate.
Turbocharger Cut-Out
Variable-geometry or sequential turbocharging feature affecting genset performance at low electrical load.
Two Stroke Diesel Generator
Rare configuration where a low-speed two-stroke crosshead engine drives a generator, found on certain LNG carriers.

U

Undervoltage Relay
Protection relay that trips a generator or load when bus voltage falls below a set point.
UnEarthed System
IT marine power system without an intentional connection between the neutral and the hull.
UPS
Uninterruptible power supply providing battery-backed power to navigation, communication, and automation systems.

V

Vacuum Circuit Breaker
Medium-voltage breaker in which contacts interrupt current within an evacuated bottle, standard on marine MV systems.
Variable Frequency Drive
Power electronic drive controlling motor speed by varying voltage and frequency.
Variable Speed Diesel
Genset arrangement where the engine speed varies with load to optimize fuel consumption, requiring power electronic conversion.
Vector Group
Transformer winding configuration designation such as Dyn11 used on marine transformers.
Voith Linear Jet
Voith axial pump propulsor with stator vanes and a rim, used on workboats and OPVs.
Voith Schneider Propeller
cycloidal propeller used on Voith Water Tractors.
Voltage Dip
Short reduction in bus voltage caused by motor starting or fault clearance.
Voltage Imbalance
Inequality between the three phase voltages, limited by class rules to typically 2 to 3 percent.
Voltage regulator
AVR maintaining generator terminal voltage at set point.

W

Wartsila 20
Compact medium speed engine used for auxiliary power on smaller ships.
Wartsila 26
Medium speed engine used on offshore vessels.
Wartsila 31
Medium-speed four-stroke engine family.
Wartsila 32
320 mm bore medium speed engine widely used for propulsion and power.
Wartsila 34DF
340 mm bore Wartsila dual-fuel four-stroke engine widely used on LNG carriers and gas-fueled merchant ships.
Wartsila 46F
Four-stroke medium-speed engine.
Wartsila Hybrid Energy Solution
Pre-engineered hybrid package integrating engines, energy storage, and PMS from Wartsila.
Wartsila Hybrid Shaft Generator
Shaft generator with full converter allowing variable speed operation and PTI and PTO modes.
Wartsila NACOS Platinum
Integrated bridge, automation, and power management product line from Wartsila SAM Electronics.
Wartsila WSP
Wartsila steerable thruster with permanent magnet motor for offshore vessels.
Wartsila WST
Wartsila steerable thruster product line for harbor and dynamic positioning service.
Watertight Door Power Supply
Dedicated UPS-backed circuit feeding hydraulic and electric watertight doors per SOLAS Regulation II-1/13.
Winding Temperature Detector
PT100 or thermocouple sensor embedded in a stator winding to monitor thermal condition.
Woodward 2301A
Analog load sharing and speed control unit historically used on marine genset paralleling.
Woodward easYgen
Genset management and PMS controller family from Woodward used widely on commercial vessels.

X

Xenon Stroboscope
Instrument used to time and balance rotating electrical machinery during commissioning.
XLPE Cable
Cross-linked polyethylene insulated cable used in marine medium-voltage power circuits.

Y

Y Connection
Star winding configuration providing access to a neutral conductor.
Yanmar 6EY
Six-cylinder medium-speed Yanmar marine engine used as main and auxiliary on commercial vessels.
Yanmar 8EY
Eight-cylinder medium-speed Yanmar marine engine in the EY26 and EY33 ranges.

Z

Zenith Voltage
Peak instantaneous value of an AC waveform, used in insulation withstand calculations.
Zero Emission Mode
Operating condition in which the ship is propelled and serviced entirely from batteries or shore power with all combustion engines stopped.
Zero Sequence Current Transformer
Window-type CT enclosing all three phase conductors to detect residual ground fault current.
Zinc Anode
Sacrificial anode for cathodic protection.
Zone Selective Interlocking
Protection scheme on marine LV switchboards in which downstream breakers signal upstream devices to delay tripping.