Page 553 - Offshore Electrical Engineering Manual

540 Index

Tension leg mooring system, 341 Triplen harmonics, 274
Tension leg platforms, 456 Tripping
in oil and gas installations, 341 batteries, 279
as wind turbine structure, 341 devices, 354
Tension leg system, 341 Truth table, 393–394, 403f
Tensioning, 341 Turbine temperature limits, 51–52
Termination and interconnection diagrams, Turbochargers, 56
194, 195f Turret, 336
Test equipment, 347 Two-pole machines, 103, 123
Test sheets, 347 Typical commissioning test sheets
THD. See Total harmonic distortion (THD) busbar testing, 465f
%THD. See Percentage Total Harmonic Distortion circuit breaker testing, 467f
(%THD) contactor starter testing, 469f
Thermal overloads, 32–33 electric motor testing, 468f
devices, 34 transformer testing, 466f
protection, 33
Thermal relays, electrical tests on, 369–371 U
primary injection tests, 370–371 UF. See Utilisation factors (UF)
Three-phase fault current, 234–235 UF(S). See Utilisation factor for surface (UF(S))
Thyristors, 111, 118f, 119 UHF (FM) radio repeater system, 177
Time multiplier (TM), 365 UK continental shelf (UKCS), 413
Top drive, 457 UK Maritime and Coastguard Agency, 343
Total harmonic distortion (THD), 274 UK Offshore Safety Case Legislation, 338
Totally enclosed fan cooled (TEFC), 105 UKCS. See UK continental shelf (UKCS)
Totally enclosed motor propelled survival craft ‘Umbilical’, 137
(TEMPSC), 113, 179 Unbalanced load(ing), 209
Touchdown/Positioning (TD/PM), 161 protection, 33
Transformer(s), 82 trip, 217
construction, 173–174, 174f Unbalanced short circuit analysis for multiple and
coolers, 343 single phase systems, 245
faults and protection devices, 211–212 Undercompounding, 84
core and interturn faults, 211–212 Underexcitation limit, 39
differential protection, 212–213 Uniformly low electrical resistivity, 140
Earth faults, 211 Uninterruptible power supply (UPS), 111–112,
magnetising inrush, 212 274, 343
oil and gas-operated devices, 213 batteries, 178
overcurrent protection, 212 Unistrut, 285
parallel transformers and intertripping, Unrestricted earth fault protection, 222–223
213–214 Unsealed batteries, 283
phase-to-phase faults, 211 UPS. See Uninterruptible power supply (UPS)
restricted earth fault protection, 212 Utilisation factor for surface (UF(S)), 151
regulation, 176 Utilisation factors (UF), 153, 154t
testing, 466f for interiors, 151–153
Transient performance tests, 349 Utility services and production switchboards, 77
Transient reactance, 37
Transient simulations, 241 V
Transits, 96–97, 97f Vacuum circuit breakers, 73–75, 356
Transmission cables, 343 Vacuum contactors, 109
Transport, 409 Vacuum interrupter, 73–75, 74f
Transporting primary injection test, 370 Valve remote control, 330–332
Tray installation, 285–286 Vapours, 303, 305
Trip supervision relay, 210 Variability of demand, 55
‘Trip-free’ mechanisms, 72 Variable speed motors, ratings for, 32