reading / British practice / Vol D - 1990 (ocr) ELECTRICAL SYSTEM & EQUIPMENT

monitoring, 70-83

needs, 2-4

operational requirements, 35 performance, 29-35

calculations, 39

performance analysis

future developments, 189-191

reliability, 36 evaluation. 87

reliability analyas control, 96 failure, criteria. 96

security, 2 standby plant

reliability, 36

station

load flow analysis, computer reliability analysis, 138 Electrochlorination plant

cooling water

electrical services, 830-834 power distribution, 834,839 production control panel, 833

Electrodes — see Earth electrodes Electrolytic cells

hydrogen production, 824-827 Electromagnetic interference

relays, 945 Electronic equipment

battery chargers, 768 mechanical plant. 805

Electronic governors diesel generators. 789

Electrostatic precipitators, 851-855 electrical supplies, 853

high voltage chamber enclosures, 855 high voltage control cubicles, 854

Emergency alarm signals siren systems, 722 Emergency control centre

nuclear power stations, 732 Emergency drives

DC systems, 766 Emergency generation, 9 Emergency lighting

DC systems, 766

Emergency operational lighting, 596 Emergency pushbuttons

generators protection, 902

Emergency stop

diesel generators, 792 Emergency stop pushbuttons

pumped-storage plant, 911 Emergency supply equipment, 748-798 Emergency telephone systems

construction sites, 742 Emergency trip control

mechanical plant electrical services. 804

Enclosures

electric motors, 630-631 expansion joints

isolated phase busbars, 306 insulation

generator main connections, 304 isolated phase busbars, 304

access platforms, 313 equipment, 304 structural steelwork, 314

mechanical plant

electrical services, safety, 803 painting

isolated phase busbars, 309 switchgear, 358

low voltage, 401 wall seals

isolated phase busbars, 305 Encounter rate

power systems

reliability, quantitative evaluation. 90 Environment

mechanical plant electrical services, 804

switchgear. 332

uninterruptable power supply systems, 60 Essential operational lighting, 596

Essential systems

electrical auxiliaries systems, 9 Ethyl vinyl acetate

cables

fire perforrnance. 526 Ethylene propylene rubber

cables, 437 fires, 523

insulation cables, 443

Ethylene vinyl acetate copolymer insulation

cables, 443 Evaluation techniques

power systems

computer reliability analysis, 105,109 Excitation

failure

generators, 902 generator-motors

incorrect, protection, 912 generators

loss, protection, 898 Excitation busbars

generator connections, 302 Excitation control

diesel generators, 791 Excitation equipment

diesel generators. 791 pumped-storage plant protection, 911

Excitation transformers pumped-storage plant

protection, 912 Exciters

diesel generators, 791 testing, 794

Exhaust manifolds

diesel generators, 789 Exhaust pipework

diesel generators, 789 Exhaust pressure high

turbines protection, 881

Exhaust steam temperatures high

protection, 886 Exhauster fans

AC commutator motors, 626 Explosiongs

terminal boxes

3,3kV motors. 390

Facsimile services construction sites, 744

Failure criteria

power systems, reliability analysis, 96 Failure events

GRASP

presentation of results, 112 power systems

computer reliability analysis, 108 definition, 96

second order

power systems, computer reliability analysis. 105, 107

third order

power systems, computer reliability analysis, 107, LOS Failure rate

batteries, 760 Flood control system

lifts, 820 Flooding

cabling

nuclear power stations, 430 Floodlights

cranes. 817

FIOON

battery rooms. 757 Flue gases

desulphunsanon retrofitting, 9 switchgear. 38

Fluorescent tubes lighting, 600

Flux fractions lighting, 590

Flywheels

diesel generators, 782 Foams

pipework

fire fighting, 862 Foil windings

transformers, 270 Foot insulators

isolated phase busbars. 305 Forced outages

power systems

computer reliability analysis, 103 types

power systems, 98 Formel NF

auxiliary transformers insulation, 267

Forward power relays turbines

protection, 883 Fossil-fired power stations

auxiliaries systems, 10 cabling

segregation, 429 Foundations

diesel generators, 783 Freezer air driers

alarm

generator transformers, 904 Frequency

generator main connections. 304 maintenance, 948

Frequency errors synchronising, 954

Frequency modulation telecommunications, 680

Frictionless bearings electric motors, 635

Frost

gas production plant protection, 822 water treatment plant

electrical services, 842 Fuel injection

diesel generators, 782 Fuel oil

heating, 857 pipework

diesel generators, 788 storage tanks

heating, electrical, 857 lightning protection, 583

Fuel oil plant

electrical services, 855-858 Fuel oil pumps

diesel generators protection, 793

electrical services, 857 Fuel oil systems

diesel generators, 787

Fumes cables

fires, 523 Fuse elements

definition, 411 Fuse switches

definition. 334 Fuseboards

lighting heating, 599

Fusegear

low voltage, 391-409 design, 393

Fuselink contacts definition, 411

Fuselinks main circuit

switchgear, 390 required performances, 412 switchgear

low voltage, 408 Fuses, 409-413

415 V

characteristics, 931 choice, 938

co-ordination with switchgear, 389 definition, 410

high breaking capacity, 930 switchgear

low voltage. 405

Gas circulators nuclear reactors

electric motors, 641,643,644 voltage profile, 156, l57

Gas detection

hydrogen production plant, 826 Gas discharge lamps

lighting, 592 Gas production plant

electrical services, 820-830 Gas storage plant

electrical services, 820-830 Gas turbines

chimneys

lightning, protection systems, 581 mechanical trips, 925 .

on-site generation, 9 protection, 924 synchronising facilities, 958 unit transformers

II kV, earth terminals, 565 Gas-turbine generating set

Avon

electrical auxiliaries systems, 35 Olympus

electrical auxiliaries systems, 35 Gas-turbine generators

11kV

synchronising, 962

synchronising supplies, 979 electrical auxiliaries systems. 35 stators

plant bonding, 565 synchronising, 973

Gas-turbine inverters

uninterruptable power supply systems, 55

Gases — see Carbon dioxide: Flammable gases; Methane; Nitrogen; Noxious gases; Oxygen: Propane; Toxic gases

Gatehouse controllers emergency alarm signals, 724

Gauss-Seidel method network equation solution

reliability analysis, 126 Generator busbar system earthing

transformers, 272

Generator earthing transformers, 271 Generator motors

incorrect excitation levels protection, 912

stationary field windings heating, protection, 912

Generator neutral earthing transformers design, 271

Generator transformers, 5-6, 219. 200 availability. 253

compound layouts, 240 connections, 310 currents, 253

design, 253-260

economics of operation, 259 heights, 254

high set instantaneous overcurrents protection, 903

HV bushings protection, 905

HV inverse time overcurrents protection, 903

i mpedance, 253 impulse strengths, 253 internal faults

protection, 904 neutral earthing, 565 noise, 253

overload capabilities, 253 performance, 255 protection, 902-905 pumped-storage plant

protection, 906 reliability, 253,255 single-phase, 254

interchangeable, 254 tap-changers, 253,254

protection, 892 transport, 251,253 voltages, 253

Generator voltage transformers design, 279

Generators (see also Main generators; Synchronous generators) asynchronous running

protection, 898 auxiliary

electrical protection, 923 protection, 922-925

capacitance, 304 data

load flow analysis, power systems, computer reliability analysis. 145

stability analysis, power systems, 180 disconnecting

switchgear, 340 earth bond networks, 565 earthing, 320

excitation

loss, protection, 898 excitation busbars, 302 fault contributions

main connections, 304 fault currents

power systems, computer reliability analysis, 166 line ends, 300

main connections, 39,287-324 capacitance, 304 evolution, 288

future trends, 323

operating temperature, future trends, 323 motoring

protection, 902 neutral ends, 300 off-load

voltage profile, 156 output

main connections, 304 power system instability, 176

protection, 886-902 representation

fault currents, computer reliability analysis, (62 rotor angles

power systems. performance analysis, 178 runaway

pumped-storage plant, protection. 911 single fed

system stability analysis, 184 stator windings

toss of water flow, protection, 901 stators

negative phase sequence, 898 neutral earthing, 320

synchronising, 949,952 sub-synchronously. 953 switch disconnectors, 341

tee-off connections transformers, 300

voltage

circuit-breakers, synchronising, 961 switchgear, 340-352

voltage circuit-breakers, 895 protection, 905

voltage profile, 157

voltage switchgear, 319-320 earthing, 302

windings, 299 G1DEAN, 67 Gland bonding

control and instrumentation cabling, 569

power cabling, 570 Gland plates

cabling switchgear, 402

Glare direct

lighting, 591 disability

lighting, 591

discomfort lighting, 591

indirect lighting, 591

lighting. 590

Governors (see also Electronic governors; Mechanical governors) composite steam/hydro

models, stability analysis, 182 stability analysis, power systems, 180

data

load flow analysis, power systems, computer reliability analysis, 145

stability analysis, 183 diesel generators, 789

performance tests, 797 testing, 796

electric

loss, protection, 886 frequency stabilisation, 948 power systems

performance analysis, 179 pumped-storage plant

protection, 913

rate

synchronising, definition, 952 set point

definition, 951 speed droop

definition, 951 stability analysis

power systems, 180 system stability analysis, 184

GRASP 1

power systems

computer reliability analysis, presentation of results, Ill reliability evaluation, 91

GRASP 2

power systems

reliability evaluation, 91 Greases

electric motors bearings, 636

Grid netitsorks

fault contribution

generator main connections. 304 Grid Sy Stems

operation criteria, 3 power station interface

computer reliability analysis. 147 voltages

electrical systems. economics, 37 Grit pumps

controls. 851

Guaranteed instrument supplies systems, 48,54 Guard relays

synchronising, 957,966 Guide vanes

pumped-storage plant protection, 913

Halon 1301

Ore fighting, 862 Harmonic analysis

power systems

performance analysis, 189 Harmonic distortion

transformers, 269 Harmonic suppressors

auxiliary transformers, 275 Harmonies

electric motors

fault currents, power systems, computer reliability analysis, 151

Hartlepool switchgear, 341

air, 345

Hazard warning lights, 598 Headgates

pumped-storage plant protection, 914

Heat exchangers forced air cooling

isolated phase busbar, 298 maintenance

transformers, 237 Heaters see also Air heaters

compressors, 859 Heating

cables, 588-601 control gear, 861

electrical services, 861-862 supplementary

cables, 598-599 Heysham 1

switchgear, 341 air, 345

Heysham 2 cabling, 428 design

electrical auxiliaries systems, 16 power system, 432

switchgear, 341

uninterruptable power supply systems, 55 High set instantaneous overcumnts

generator transformers protection, 903

unit transformers protection, 903

Humidifiers

electrical services, 862 Hydrastep system

water level protection. 874

Hydraulic control fluids

contamination

overspeed trip. protection. 883 turbines

protection, 880 Hydro power stations

cabling segregation. 429

electrical auxiliaries systems, 22 Hydrochloric acid

polyvinyl chloride burning. 523

Hydrogen

battery rooms, 757 compressors

control. 827 high temperature

protection, 901-902 production

electrolytic cell process, 824-827 methanol chemical reaction, 827-829

uses, 821

water cooling flow stator, 902

Hydrogen bromide cables

fire performance, 530 Hydrogen chloride

cables

fire performance, 530 polyvinyl chloride

cables, fires, 545 Hydrogen plant

electrical services, 805 lighting, 597

Hysteresis loss transformers

silicon content, 198

Illumination (see also Lighting) levels, 593

Impedance

earth electrodes measurement, 572

generator transformers, 253 unit transformers. 262 variation

transformers, 219 Impulse strength

generator transformers, 253 Impulse testing

transformer windings, 212 Impulse tests

transformers. 249 Indicating instruments

switchgear, 373 Induction motors

current decays

power systems, computer reliability analysis, 150 data

load flow analysis, power systems, computer reliability analysis, 145

stability analysis, 183 power systems

computer reliability analysis, 160 pulse-width-modulated converters. 628 representation

power systems, computer reliability analysis, 164 run-up

load flow results, 190

power systems, stability analysis. 189

slip

system stability analysis, 185 speed

system stability, 183 start-up

load flow results, 190 system stability analysis, 184

variable-speed slipring boiler feed pumps, 640

Inductors fault levels

poy.er svstems, computer reliability analysis. 151 uninterruptable poser supply systems, 62

Inspection

li ghting, 599 Installation

cable systems, 601 cables, 453.512-522

contract management information. 604 troughs. 517

power cables single-core, 455

site

generator main connections, 314 transformers, 251-253

Instrument transformers design, 278-286

Insulation ageing

oxygen, 227 transformers, testing. 250

auxiliary transformers, 263 cables, 437

II kV, 438 cast-resin

auxiliary transformers, 265 dryness

transformers. monitoring, 245 electric motors

life, 802

thermal overload relays, protection, 928 windings, 634-635

windings, type tests, 634 tire barriers

cables. 547

generator voltage transformers, 280 graded

transformer windings, construction, 210 paper

cables, 437 shrinkage

transformers, 218 switchgear, 354

3.3kV, 180

low voltage. 402 transformer windings construction, 210

transformers, 196.198 manufacture checks, 244

power frequency overvoltage tests, 247 Insulators

electrostatic precipitators high voltage, 855

generator main connections testing. 314

isolated phase busbars, 304-306 Enterconnecuons

electrical aux,iliaries systems. 8 Interconnectors

fault levels

station electrical systems, computer reliability analysis, 1 67, 168

transformers, 72 Interference

electrostatic precipitators. 855 half IF, 717

multicore cables

control and instrumentation, 480 multipair cables

control and instrumentation, 477 radio systems. 715-717

Interference theory

cables

control and instrumentation, 476 Interlock types

definition, 72 Interlocking, 70-83

electrical systems maintenance, 75

generator main connections maintenance, 323

mechanical plant electrical services, 804

operational

electrical systems. 71 Interlocking equipment

cable network systems, 485 Interlocking schemes

application

electrical systems. 72 general. 72

Interlocks (see also Electrical interlocks; Maintenance interlocking; Mechanical interlocks; Travel interlocks)

cranes, 813-816 diesel generators, 792 electrical

mechanical plant. electrical services, 804 mechanical

mechanical plant, electrical services, 804 sequence operational

electrical systems, 74 switchgear

DC systems, 765 turbines

protection, 883 Intermodulation products

radio systems, 715 Inverse time overcurrent

generator transformers protection, 903

unit transformers protection, 903

Inverse time relays characteristics, 931 current grading, 935 time grading, 935,936 transient overreach, 936

Inverter output voltage tolerance uninterruptable power supply systems, 62

Ion-exchange resins water treatment

electrical services, 836 Ionisation chamber detectors

fires, 865 Iron

transformers, 196 Isolated phase busbars, 287

air-insulated

delta connections, 301 cooling

forced, 297-299 design, 294-297 electrically-continuous

short-circuit, 289 forced air cooling. 298

forces, 289-294 liquid cooling, 298 oil cooling

transfmer cooling, 298 operation, 289-294

system description, 299-303 voltage rise

fault conditions. 294 water cooling, 298

Isolation lighting, 599

power systems

computer reliability analysis, 100 Isolators

coupling equipment

antennas. 702 definition, 334 -

Isotropic radiator

radio signals propagation, 683

I-brackets

cable support systems, 504 Jamming

cable pulling, 520 Joints

conductors

isolated phase busbars, 311-312 earth bars

earthing. switchgear, 367 expansion

conductors, isolated phase busbars, 306 enclosures, isolated phase busbars, 306

resistance

temperature measurement, isolated phase busbars, 313 lumpering

cable network systems. 482-494

Key exchange boxes electrical systems

maintenance interlocking, 81 Knee point EMF

current transformers, 285

Labelling

switchboard circuits, 373 Ladder racks

cable support systems, 499,501,503,517 cleating, 513

Lead acid cells see also Batteries gas recombination

power supplies, telecommunications, 657 Lead resistance

synchronising, 978 Leakage reactance

generator transformers, 253 transformers, 197

Lifts

audible alarms, 820 brakes, 819

car control facilities, 819 car emergency hatches. 820 car lighting, 819

cars, 819 drive systems

electrical, 818

hydraulic, control systems, 819 earthing, 820

electrical services, 819-820 fireman's control systems, 820 landing equipment, 819 maintenance facilities, 819 motor rooms

equipment, 818 motors

protection, 819 power distribution, 818 power supply, 818 requirements. 818 shafts

flooding, 820 lighting, 820

types, 818 Light obscuration smoke tests

cables, fire performance, 527

Lighting (see also Access lighting; Aircraft obstruction lighting; Emergency lighting; Emergency operational lighting; Essential operational lighting; Floodlights; Illumination; Luminaires)

appraisal, 595 battery rooms, 757 cables, 588-601

design, 588-596 economics, 591 emergency, 596-597 general, 589

lamps, 621 lift cars, 819 lift shafts. 820 local, 589 localised, 589

objectives, 588 special areas, 597-598

Lightning

fuel oil storage protection, 858

gas production plant protection, 821

impulse voltage testing

generator main connections. 314 magnitudes. 575

protection, 556.574-587 antennas, 705 cables, 550

fuel oil storage tanks, 583 protection earth electrodes

resistance, 587 protection systems

design, 581 inspection, 587 records, 587 sideflashing, 584 testing, 587

return stroke, 575 risks, 575 transformer windings

testing, 212 transformers

impulse tests, 249

Lights

paging systems, 666 Limit switches

cranes, 813-816 Limited energy sources power systems

reliability evaluation, 92 time limit

power systems, reliability evaluation, 93 Limited fire hazards

cables, 523

Limited voltage recharging batteries, 761

Line currents

generator connections, 304 Line data entry

computer reliability analysis power systems, 160

Linear differential equations solution, 135

Linear heat detecting cables, 442 Linear motors

future trends, 646 Littlebrook D

cabling, 428

electrical auxiliaries system, 10 guaranteed instrument supplies system

station, 53 unit, 48

Load disconnection automatic

power systems, performance analysis, 179 Load flow analysis

complex variables, 124 data requirements

power systems, computer reliability analysis, 144 power systems, 117-148

computer reliability analysis, 174,175

. program construction, 120 station electrical systems

computer reliability analysis, 138

Load flow calculations power systems

computer reliability analysis, 174, 175 Load flows

convergence accuracy

power systems, computer reliability analysis, 1 47 data

power systems, stability analysis, 180 number of iterations in solution algorithm

power systems. computer reliability analysis. 147 power network, 120

Load losses transformers, 200

Loading resistors

generator main connections testing, 315

generator neural earthing transformers, 272 Locking

circuit-breakers, 373 electrostatic precipitators, 855

Loss of boiler water protection, 871 Loss of electric load protection, 873

Loss of feedwater protection, 876

Loss of feedwater flow protection, 871

Loss of generation power systems

reliability, quantitative evaluation, 90 Loss of grid supplies

electrical systems, 33 load flow analysis

computer reliability analysis, 140 Loss of lubricating oil pressure

turbines protection, 880

Loss of pumping power pumped-storage plant

protection, 911 Loss of revenue

power systems

reliability, quantitative evaluation, 90 Loss of steam demand

protection, 879 Loudspeakers

nuclear power stations, 729 Low drum levels

boilers

protection, 871 protection, 873

Lubricating oil low pressure

auxiliary generators. protection, 923 priming

diesel generators, 782 priming system

diesel generators, 792 temperature low

auxiliary generators, protection, 923 turbines

cabling. 430 water jacket heaters

diesel generators, 794 Lubricating oil systems

DC motors, 628 Lubrication

diesel generators, 780 Lugs

soldered

power cable conductors, terminations, 533 Luminaires

classification, 590 lighting, 621 types, 589

utilisation factors, 591 Luminous area

lighting, 590

M87 control system operational description, 706

Machine controllers stability analysis

power systems. 180 Magnetising inrush current

auxiliary transformers, 269 Magnox nuclear power stations

electrical auxiliaries system, 12 Main connections busbar system

functions, 287 Main distribution frame

private automatic exchanges, 662 Main earth networks

construction, 562 Main generators

electrical systems, 4-5 Main inlet valves

pumped-storage plant protection, 914

Main steam valve spindles overspeed trip

protection, 883

Main telecommunications moms, 652 equipment, 653

power supplies, 653 Main transformers

battery chargers, 770 Main water treatment plant

electrical services, 836 Maintenance

electrical systems, 44-45 operational, 44

generator main connections earthing, 321-323

interlocking

electrical systems. 75 lighting, 599

rate

power systems, reliability evaluation, 93 safety

electrical systems, 44 time

power systems, reliability evaluation, 93 uninterruptable power supply systems, 62

Maintenance and commissioning telephone jack systems, 653, 722

pumped-storage power stations, 741 Maintenance interlocking

electrostatic precipitators, 855 Maintenance socket outlets

cranes, 817 Maintenance transition rate

power systems

computer reliability analysis, 103 Manual synchronising, 955,956

burdens, 978

steam turbine-generators

generator voltage circuit-breakers, 982 Manual trip levers

turbines protection, 882

Markov state-space models power systems

computer reliability analysis, 101 Matching transformers

protection, 890

Matrix tripping systems, 915 Mean time between failures

power systems

reliability, quantitative evaluation. 90 Mean time to repair

power systems .

reliability, quantitative evaluation, 90 Mechanical governors

diesel generators, 789 me chanicai interlocks

switchgear

low voltage. 404 Mechanical plant

electrical services, 799-867 control circuits, 803 trip circuits, 803

Mechanical trips

auxiliary generators, 923

Melamine insulation

transformers, 270 Mercury Communications Ltd

telecommunications future trends, 744

Meta!clad switchgear movable earth, 328 work using, 329

Metallic screens cables, 451

Meter rooms lighting, 592

Methane production plant

electrical services, 829-830 uses, 821

Methane, bromotrifluorofire fighting, 862

Methanol

hydrogen production, 827-829 Method of symmetrical components

power systems

computer reliability analysis, 162 Microwave links

telecommunications future trends, 744

fvfidel 7131

auxiliary transformers insulation, 267

Milling plant

electric motors, 640 Mineral oil

transformers, 196 Minimal cut set

power systems

computer reliability analysis, 96 Minimal cuts

GRASP 1

presentation of results, 111 Minimal paths

GRASP 1

presentation of results, 111 power systems

computer reliability analysis, 96

computer reliability analysis, deduction, 96 Minimum cut sets

power systems

computer reliability analysis, deduction, 96 Moisture

transformers

insulation ageing, 227 Monitoring

battery chargers, 769 electrical systems, 71

Monitoring systems nuclear power stations

cabling, 430 Motor circuits

415 V, 474 protection, 927

3.3 kV, 474 protection, 927

IIkV, 473 protection, 927

main protection, 620 Motor-generator set schemes, 46 Motoring

generators, 952

protection, 902 Motorised rollers

cable pulling. 521 Motorola-Stomo CAF2200 system

operational description, 708

National cable networks

British Telecommunications plc telecommunication circuits. 658

National grid systems communication links, 650

Negative phase sequence generators

protection, 898 Network branches

power systems

fault currents, computer reliability analysis, 165 Network cable systems

commissioning. 490 plant-mounted devices, 490 testing. 490

Network connections fault conditions

power systems. computer reliability analysis, 163 Network diagrams

data entry

power systems, computer reliability analysis, 141 drawing

power systems, computer reliability analysis. 141 Network equations

solution

reliability analysis, 126

Neutral earthing transfouners. 271-276

Neutral eanhing equipment isolated phase busbars, 314

Neutral earthing resistors. 555 3.3kV cables, 439

11 kV cables, 438 Newton-Raph son method

network equation solution reliability analysis. 127

Nitrogen storage plant

electrical services, 830 uses, 821

Nodal analysis load flow

power network, 121 Nodal failure events

GRASP 1

presentation of results, I ll

Noise enclosures

isolated phase busbars. 305 generator transformers, 253 local-to-plant

mechanical plant, electrical services, 805 mechanical plant

electrical services, 805 suppression

radiotelephones, 714 Non-linear differential equations

stability analysis power systems, 179

Noxious gases cables

fires, 442 Nuclear alarrns

power feeds cables, 494

Nuclear emergencies radio services. 734

Nuclear incidents

emergency telecommunications, 732 Nuclear plant

electrical systems

operational requirements, 35 loss of grid supplies. 34

Nuclear power stations battery chargers

safety, 769 cabling

segregation. -130 cranes

DC motors, 807 electrical services. 817

electrical auxiliaries systems. 7 electOcai systems. 4

desien, busbar indices, 113 emergency lighting, 596 essential systems, 9

fire barriers cables, 542

lighting, 588

loss of grid supplies, 33 mechanical plant

electrical services, 805 on-site generation, 9 standby earth faults

protection. 903 telecommunication requirements, 652 telecommunications, 726-734 tripping schemes, 915

Nuclear reactors AGR

electric motors, 641-642 emergency supply equipment, 749 PWR

electric motors, 642-645 Number systems

power systems

computer reliability analysis, 94 Numbering

electrical systems quality assurance, 45

Numerical indices power systems

reliability, quantitative evaluation, 90

Oil coolers

diesel generators, 780 Oil flow washers

transformer windings, 215 Oil-fired boiler units

electric motors, 640-641 Oil-fired power stations

electrical systems

maximum load, voltage profile, 154 minimum load, voltage profile, 154

station electrical systems analysis diagram, 152

Oils (see also Fuel oil; Lubricating oil; Mineral oil) circulation

transformer windings, heat production, 215 preservation

transformers, 227 transformer cooling

isolated phase busbar, 298 transformers

dryness, 227

Olympus gas-turbine generating set AGRs• 36

Avon, 35 On-line computing

interactive

electrical systems, analysis. 86 Operating air plant

switchgear, 353 Operating frequency

antennas, 685 Operating time

fuses

definition, 412

Operational telephone systems. 651 Operations support centres

nuclear power stations, 734 Optical smoke detectors. 865 Orifice plates

water cooling transformers, 235

Outage time annual

GRASP 1, presentation of results. Ill power systems

reliability, quantitative evaluation. 90 Outages

forced

station plant, electrical auxiliaries systems, 34 planned

station plant, electrical auxiliaries systems, 34 station plan(

electrical auxiliaries systems, 34 Output frequency

uninterruptable power supply systems, 63 Output voltage

adjustment

uninterruptable power supply systems, 62 Output voltage waveform distortion

uninterruptable power supply systems. 64 Over frequency

protection

pumped-storage plant. 910 Overfluxing

generator transformers protection, 904

Overload capability

generator transformers. 253 unintemmtable power supply systems, 64

Overload currents cables, 462

Override synchronising, 952 Oversheaths

cables

mechanical performance. 445 Overspeed

auxiliary generators protection, 923

pumped-storage plant protection, 910, 913

Overspeed trips

diesel generators, 789 turbines

protection, 883 Overvoltage protection

battery chargers. 769 Overvoitages

generators protection. 888

pumped-storage plant protection, 911

Oxygen

insulation ageing transformers, 227

Oxygen index tests fire performance

cables, 526

PABX — see Private automatic branch exchanges Paging systems, 666-668

inductive loops, 666 lights, 666 sounders, 666

uses, 668 Painting

conductors

isolated phase busbars, 309 enclosures

isolated phase busbars, 309

Paints

flame retardant