MIN 654 • Module 30 • Marine Engineering Oral Preparation

Shore-Power Connection

High-detail interactive infographic for high-voltage shore connection, compatibility reports, risk assessment, switching plan control, cable connection, PMS transfer, monitoring, return to ship power and examiner-style fault response.

Built for examiner questions, not just revision.

This Module 30 version uses the same TST infographic shell and card structure as the electric-propulsion example, but the content is rebuilt around shore-power connection, compatibility and safe operational control.

System routeShore supply to ship loads FrameworkSOLAS, MEPC, IACS/Class CompatibilityReport before accepting supply Risk controlsRA/PTW, switching plan, people ConnectionCables, plugs, interlocks TransferPMS, monitoring and return

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Quick oral memory route

Compatibility

Voltage, frequency, phase sequence, synchronising, earthing, fault level, protection, load limit, power quality and cables.

Work pack

Risk assessment, permits, switching plan, communications, authorised people and contingency plan.

Connection

Prove safe condition, inspect plugs, support cables, confirm pilot/control paths and E-stop/enable.

Transfer

PMS synchronises, transfers load, monitors shore supply and returns to ship generation by plan.

Section 1

Representative shore-power route

Shore gridUtility / port supply

Transformer / converterVoltage or frequency matching where fitted

Shore switchboardBreaker, protection and ground switching

HV cables + pilotPower plugs plus control / interlock path

Ship SC panelIncoming breaker, earthing and protection

PMSSynchronising and load transfer

Main switchboardShip distribution

Ship loadsHotel and essential services within shore limit

Oral line

“I would describe both the power path and the safety path: shore board to HV cables, ship shore-connection panel, PMS/synchronising and main switchboard, with permits, interlocks, E-stop, communication and approved procedures controlling the operation.”

Section 2

SOLAS / MEPC / IACS / Class framework

Technical interface

Use IEC/IEEE 80005 as the general ship/shore connection framework, then apply vessel drawings, maker manuals, class/flag, SMS, port authority and shore-provider procedures.

Environmental context

MEPC/MARPOL context supports emission reduction while alongside; it explains why cold ironing is used, not the electrical switching sequence.

SOLAS / ship safety

The electrical installation, emergency source, protection and essential services must remain safe. Do not invent universal settings; use approved vessel data.

IACS / Class

Class and IACS-member rules/surveys control approved ratings, shore-connection equipment, earthing, protection, testing and notation requirements.

Section 3

Compatibility report before accepting supply

Voltage

Nominal and permitted tolerance must match; low voltage increases current for the same power.

Frequency

50/60 Hz must match or approved conversion must be provided.

↻

Phase sequence

Wrong sequence can reverse motors and must be blocked.

∠

Synchronising

Voltage, frequency and phase angle must be within synch-check limits.

⏚

Earthing / bonding

Neutral and earth philosophy must be compatible to avoid touch voltage and protection failure.

Icc

Fault level

Short-circuit level and protection coordination must suit ship equipment.

Load limit

Shore kW/kVA compared with expected load; PMS shore limit set.

THD

Power quality

Harmonics and voltage quality must be acceptable.

🔌

Cables / connectors

Rated, clean, dry, undamaged, correctly latched and supported.

P = √3 × V × I × PF

For the same power, lower voltage means higher current. Outside approved tolerance, do not accept the shore supply.

Section 4

Risk assessment, switching plan and work pack

Electrical hazards

Shock and arc flash.
Wrong phase or out-of-sync closing.
Earth fault, backfeed or stored charge.
Protection bypass or blind reset.

Mechanical hazards

Heavy HV cables and plugs.
Bending radius and cable tension.
Tide, swell and mooring movement.
Damaged pins or wet connectors.

Operational hazards

Blackout or partial blackout.
Loss of propulsion/thruster readiness.
SIMOPS, cargo, bunkering or passenger movement.
Poor ship/shore communication.

Oral line

“I would not start cable handling until the RA, permits, switching plan, competent personnel, shore-provider communication, port approval, load limit, PMS settings and contingency plan were in place.”

Section 5

Safe connection sequence and cable control

Confirm berth-specific procedure, responsibilities and communication.
Complete RA/PTW, SIMOPS review and switching plan.
Confirm ship alongside condition, weather, tide, moorings and emergency readiness.
Confirm shore/ship compatibility report and PMS load limit.
Prepare boards: breakers open/racked as required and earth/ground status correct.
Prove safe condition before handling plugs; use approved HV test equipment and PPE.
Inspect plugs for moisture, salt, cracks, bent pins, covers, interlocks and latches.
Connect power, earth/neutral and control/pilot plugs only in the prescribed order.
Support cables, maintain bend radius, monitor tension and control access.
Prove E-stop / enable / plug-position / ground-check circuits before energisation.

Section 6

PMS transfer, monitoring and return to ship power

Transfer to shore

Keep one DG online and stable for controlled transfer.
Confirm no blocking alarms or failed interlocks.
Shore ready and synch-check satisfied.
PMS closes shore breaker, shares load and transfers load to shore.
DG unloads/stops only as per approved procedure.

Return and disconnection

Notify shore, bridge and ECR.
Start/prepare ship generation and synchronise.
Transfer load back to ship power.
Open shore breaker and isolate.
Prove dead and earth/ground before cable disconnection.
Close records, defects and handover status.

Never bypass: synch-check, undervoltage, underfrequency, earth fault, breaker interlocks or E-stop circuits to force closure. Failed PMS closure means investigate the precondition.

Section 7

Protection, interlocks and monitoring

27

Undervoltage.

46

Negative phase sequence.

51 / 51N

Overcurrent and earth fault.

59N / 86 / 51BF

Residual overvoltage, lockout and breaker failure.

Watchkeeping

Monitor voltage, frequency, current, load, PF/kVAr, power quality, cable tension and connector temperature.

Trip response

Recover ship generation, inform bridge and shore, inspect only when safe and do not reconnect blindly.

Cable alarm

Stop work/transfer as required, adjust cable management or moorings and continue only when safe.

Section 8

Examiner model answers

Talk me through the connection.

Start with compatibility, RA/PTW, competent persons and communications. Then prove the connection safe, inspect and connect cables, prove interlocks, transfer with PMS, monitor, return to ship power and close records.

What is in the compatibility report?

Voltage, frequency, phase sequence, phase angle, earthing, short-circuit level, protection, load limit, power quality, E-stop/enable and cable condition.

Could you accept low shore voltage?

No, not outside approved limits. For the same power, lower voltage means higher current and can overheat cables/connectors and trip protection.

What if shore power trips?

Recover ship power, inform bridge and shore, check PMS/protection alarms, inspect only when safe, record the event and repeat compatibility/safety checks before reconnection.