Standards

Marine Electrical Standard

Requiremnent

Lesson overview

• Shore based connection requirement for equipment for shipboard equipment

• Electrical system and dynamic marine environment- vibration and voltage fluctuation

• SOLAS minimum requirements for electrical machinery installation

• Electrical equipments installation on board ship - From indicator bulb/lamp up to main propulsion

Objectives

• To know general requirements for electrical

machinery on board ship

• To understand general requirements for

provision of electrical power and lighting for

normal & emergency operation

• Must meet minimum standards specified by various national & international organizations

• For British registered vessel, to comply:– Regulations for the Electrical and Electronic Equipment of

Ships - Institution of Electrical Engineers (IEE)

– British Standards Institute (BSI) - combined with Recommendations for Electrical and Electronic Equipment of Offshore Installations

• The Merchant Shipping Rules - MCA

• SOLAS – IMO Convention

• British Standards (BS)

• International Electrotechnical Commission (IEC)

Introduction

Introduction • General requirements - refer to SOLAS requirements

• Chapter II-1 - outlines requirements for Ship construction sub-division and stability, machinery and electrical installations

• 5 Parts:– Part A General

– Part B Sub-division and stability

– Part C Machinery installations

– Part D Electrical installations

– Part E Additional requirements for periodically unattended machinery spaces

• Part D: – Regulation 40

• General

– Regulation 41 • Main source of electrical power and lighting systems

– Regulation 42 • Emergency source of electrical power in passenger ships

– Regulation 42-1• Supplementary emergency lighting for Ro-Ro passenger ships

– Regulation 43 • Emergency source of electrical power in cargo ships

– Regulation 44 • Starting arrangements for emergency generator sets

– Regulation 45 • Precautions against shock, fire and other hazards of electrical origin

• Standards specified met when ship is designed,

built, approved and classified

• Ship owner & operating staff to maintain

vessel and its electrical installation to Class

requirements throughout ship's lifetime

• Periodical survey - to check installation is

maintained to Class Rules

Items subject to survey• Generators and Governors

• Circuit Breakers

• Switchboards and Fittings

• Cables

• Insulation Resistance

• Motors and Starters

• Emergency Power Equipments

• Parts of Steering Gear

• Navigation Light Indicators

• UMS vessels

• Tankers

• For UMS - survey of associated alarms, controls and

fire detection is required

• For tankers/gas carriers & others transporting

flammable cargo - additional survey for electrical

equipment in hazardous areas

• Carried out during each docking survey & annual

survey - Means - electrical equipment in hazardous

area is surveyed every year

Generators & Governors

• Clean

• Respond correctly to controls & load changes

• Stable operation when running in parallel

• Windings - free of dust, oil and moisture

• Visual check - deterioration, abrasion or cracking of insulation around winding end coils on stator

• Insulation test to carry out while machine still hot after running on load

• Minimum 1.5 MΩ for new equipment

• Surveyor - > 1kΩ/volt min value for 440V genset

• HV equipment – min IR level (kV + 1) MΩ

• e.g. for 6.6 kV motor, the acceptable min IR would be 7.6 MΩ


• Appropriate action taken before carried out megger test

• Contact surface of commutator or slip-rings

• Contact surfaces – smooth & concentric without signs of pitting or deep grooves

• Carbon brushes - adequate length, correct spring pressure and properly contoured onto its commutator or slip-ring

• Important to remove excess carbon dust in brush gear & around rotor coils

• To run tests, on load, confirm of proper governor & AVR operation

• Correct indication – V, f, A, kW, power factor

• Governor response to sudden load changes - within declared specification

• Stability of load sharing during parallel operation - clearly demonstrated


Circuit breaker

• Visual examination - main, arcing and auxiliary contacts for wear, misalignment and overheating

• Similar inspection - fixed and moving isolator contacts at rear of circuit-breaker

• Arc chutes - clean, free of arc debris and correctly aligned

• Internal wiring - good condition & end connections tight

• Mechanical linkages - checked for wear or stress

• Tests

– close and trip operations while in isolated position

– racking mechanism - free moving & fixed main terminals must shuttered off when breaker is withdrawn

• Emergency hand charging (if fitted) - correct operation of mechanical indicators (open, closed or isolated)

• UV release mechanism & OCR settings for level and time delay - clearly set

• Basically, OCR trip generator breaker - set for 130% of FLC with 3s delay

• In addition, to suit generator thermal capacity & coordinated with overall protection scheme for power system

• Only proper current injection test – prove manufacturer's I/t characteristics & settings (specialist task)

• CB time delay mechanisms with oil dash pots – to filled to correct level with clean oil of maker recommended type

Circuit breaker

Switchboard & fittings


http://www.ship-technology.com/contractors/electrical/abb2/

• Section / distribution board – clean

• Includes all internal / external panel surfaces, instrument faces and control switches

• Thorough cleaning inside main swbd carried out only when the board is completely dead

• Bus-bar & aux connections checked for tightness during major internal clean up

• Overheating signs at connection - loose joint

• Direct heat testing (IR thermal camera) - useful technique for locating hot-spots

• Bus-bar supports - examined for surface tracking & damage to insulation material

• All internal wiring securely fixed

• Cable entries at bottom of switchboard sealed with non-flammable material –prevent dirt & act as fire stop

• Earth bar securely bonded to both board frame (ship's hull)


• One secondary terminal of each CT) and instruments and relays metal cases should wired to main earth bar

• Hinged panel doors bonded with earth strap to swbd frame

• Feeder isolator & fuse holder contacts - checked for mechanical wear / damage due overheating / arcing at contacts

• Lightly smear moving contacts with contact lubricant –recommended

• Operational tests - synchronising controls & generator protection relays (reverse power & preferential tripping)

• Typical reverse power trip settings – 5~15% of generator power rating, with 0.5~2.5 sec for diesel drive

• 2~5% and 5 s - turbo-generator settings

• E.g - cargo winches & cranes may feed power back into supply network, under light load, such feedback may cause generator to trip on reverse power if time delay set too short


Cable

• Close visual examination beside megger test

• Inspection - external damage of cable's outer sheath and wire or basket weave armouring (if fitted)

• Adequately supported along horizontal / vertical runs by suitable clips / ties

• If running along open deck with expansion loops - examined for abrasion and wear

• For cables pass though bulkheads - correctly glanded or through stopper boxes, prevent fire passage between compartments

• Common insulations onboard - EPR (ethylene propylene rubber) or butyl rubber, sheathed with PCP (polychloroprene) or CSP (chlorosulphonated polyethelene)

• EPR/butyl subjected to oil vapour - to tape / sleeve cable ends

• Flexible cables to light fittings, power tools, etc. - inspected for mechanical damage, repeated dragged and chafed

• Copper strap / flexible earthing braid/wire - bond equipment steel frame to ship's hull

Cable

Insulation resistance

• Surveyor - results of recent insulation tests on

all 440V & 220 V

• List indicate test date's, weather conditions

(hot, humid, etc) & comments (e.g. machine

hot or cold)

• For generators & main motors - IR trend,

history of past results

Required to test on selected motors

• Visual examination - frame & terminal for damaged or missing parts

• General neglect suspected if motor covered with dirt, oil or rust

• TEFV induction motors - require less attention as windings well protected

• Drip proof, weatherproof & deck water tight – thoroughly inspected

• May need to open - check ingress of oil / water, insulation damage & internal corrosion

• Commutator / slip-ring - checked for rotary contacts and brush gear

• Cargo cranes and winches are not strictly part of a survey as they are not considered essential to the safety of the ship.


• Running test – vibration, noise, worn out bearings & ampere compared to rating plate

• Remote stop/start buttons, regulating resistors etc. - check for burned & misaligned contacts

• General condition of starter equipment - loose connections, worn pigtails on moving contacts, badly carbonised arc chutes & overheating on coils, transformers & resistors

• Dust / weather proof features - in place & serviceable

• Functional checks – starts from local, remote and emergency, signal lamp status

• OCR trip settings compared with motor FLC rating

• Fuse size & type for starter - checked against maker's drawings & motor rating


Electrical power & associated equipment

• Sequence & operation of emergency generator - manually & automatically

• Emergency switchboard - voltage, current and frequency checked when powered by emergency generator

• Functioning of emergency lighting, fire pump & other emergency equipment

• Interlocking arrangements between main & emergency switchboard

• Auto-start relays (voltage / frequency operated) examined and tested

• Emergency battery installation & charging rectifier

• Battery – dry, well ventilated, top parts clean, terminal & connections free from corrosion & greased, proper electrolyte level & correct SG value

• Safety notices & PPE available adjacent to batteries & proper ventilation

• Battery charging equipment - checks for dirt, overheating, loose connections & correct functioning of indicators, instruments and alarms

Steering gear parts

• 3 important parts:– Power unit

– Steering control

– Indications and alarms

• Power unit - duplicate motors & starters supplied from main swbd

• SOLAS requirements - one motors to be supplied from emergency swbd

• Motors, starters & c/o supply switch units to be inspected

• Rudder control (hydraulic telemotor or electric controller), supplies, changeover facilities for steering wheel and auto pilot must tested & well functional

• Rudder swung from 32° port to 32° stbd in 28 sec with loaded condition

• SG status indications operate correctly - steering flat, MCR & on bridge

• Bridge indication should compared with direct mechanical indicator on rudder stock in steering flat

• Motor over current alarms – test by simulating over current relay

• SG motor does not have OCR protection – fuses only

• Hydraulic low level alarms - correct initiation by level sensors

Steering gear parts

Navigation light indicators

• Indicator operates correctly & shall gives appropriate alarms

• Simulation – by pulling the fuse

• Power supply must duplicated & c/o facilities checked

• Visual inspection on cable to the lights

• Actual light fittings for navigation - part of Safety Equipment Survey

Navigation light indicators

UMS operation• Apart from basic survey, additional survey required to include

alarms, fire detection, controls and fail-safe features

• Alarms associated with ME, AE, lubrication & cooling - tested for correct operation

• Testing of circuits for sensors – manually by switch or simulate to alarm condition - prove function correctly

• Sensor calibration & alarm annunciators – specialist

• Initiation and action of automatic shut down features to be tested

• Essential drives for lubrication, cooling & fuel are duplicated - on duty/standby basis, automatically start up standby unit if duty pump pressure loss

• Automatic start-up (under voltage & under-frequency relay) of emergency generator demonstrated, run up to speed & supply voltage to emergency swbd

• Stby generator starts automatically if loss of duty generator & supplying voltage within 45 sec

• Followed by automatic restarting of essential auxiliaries - lubrication, cooling, fuel & steering

• Bilge level alarms with automatic bilge pumping must proven

• Main & stby power supplies to overall alarm monitoring system - inspected & tested

• Stby power arrangement - backup battery & its trickle-charger to inspect

• Tests made on UMS alarm system to verify:– alarms displayed on main console relayed to group alarm panel on bridge

– duty engr call system - duty engineer cabin, duty mess and lounges

– Allowance of 2-3 minutes to respond to machinery alarm, otherwise dead man alarm sounded

• Complete inspection / test of fire detection system

• All smoke, heat & flame sensors - function correctly, giving audible & visual alarms

• Hand operated fire alarm switches (break glass) - examined & to be tested

• ME controls functional & tested from bridge, local & emergency position

• Operational features of ME control & indication - demonstrated during full engine test

• All equipment & connections associated with engine control - examined for wear & tear, insulation level, cleanliness, loose connections and overheating

UMS operation

Tanker • Electrical equipment - surveyed every 4 yrs & during docking

• Hazardous area electrical equipment - surveyed every year

• Common hazardous area electrical equipment - flameproof enclosure type (Exd) - light fittings, motors, starters, push-buttons and alarm bells

• Inspected for surface cleanliness, corrosion & secure mountings

• Light fittings – cement, bonds the lamp glass to its frame - inspected for cracks or indentations

• All bolts in place, evenly torqued-up and of correct type

• Edges of ‘Exd’ flamepath flanged joints - not painted over / impeded

• Must be adjudged weatherproof with correct (approved) gaskets or O rings in place

• Fittings may opened up - check condition of flamepath surfaces for corrosion, pitting or scratches

• Ex Certification & equipment rating label must not painted over

• No alterations allow on Exd equipment without permission from Certification Authority - lamp size & its rating

Exd Flamepaths

• Pump rooms - pressurized light fittings (Exp)

• To confirm - fittings are purged & pressurized before light is switched on

• Lights automatically switched off if air pressure drops

• Instrumentation & communication equipment - must intrinsically safe (Exi)

• Most Exi - zener barriers connected in line with IS circuits & fitted in safe area, outside hazardous area

• Test zener barriers – uneasy task, accepted if equipment function correctly when circuit fault arise

• Visual inspection during installation

• Barriers have secure connections & bolted to earth strap, bonded to ship's hull

Exi Barrier Circuit

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