RE-ENERGIZATION - BC Hydro - Transmission

BC HYDROREAL TIME OPERATIONSOPERATING ORDER 1T-29ARECLOSING (RE-ENERGIZATION) POLICYSupersedes 1T-29A issued 14 June 2012Effective Date: 26 February 2014Review Year: 2018APPROVED BY:Original Signed by:Paul ChoudhuryGeneral Manager,Real Time OperationsDenotes Revision

OO 1T-29AEffective: 26 February 2014Page 2 of 81.0 GENERALThis Operating Order (OO) specifies the reclosing policy following an automatic tripout for: Transmission lines, Generators, Transformers and reactors, Synchronous condensers, Substation busses including SF6 busses.Privately owned transmission circuits and generating equipment operated by BCH must also complywith these rules and references in Operating Orders.Related Operating Orders1D-51 Distribution Substation Feeder Reclosing Policy, and1D-03 Field Reclosers, and1T-29B Distribution Substation Main Feeder bus Reclosing Policy (35 kV and Below).2.0 EXTRAORDINARY CONDITIONSUnder extraordinary conditions the System Control Manager (SCM) shall authorize; Reclosing on Level 1-4 transmission equipment and lines. Reclosing on Level 4 and 5 distribution equipment and lines.Extraordinary Conditions are those where; Energization is required for restoration of essential services, Re energization will reduce impact of potentially lengthy customer outages, Unusual local conditions warrant such an exception.3.0 RESPONSIBILITESOperators at the BC Hydro Control Centre must follow the policies set out in the following sectionsControl Centre Operators must discuss with the SCM on shift before instructing the Field Operationsstaff to reset lockout relays. If necessary, the Control Centre should consult BCH Field Operationsmanagers. The ultimate decision making responsibility rests with the SCM. The SCM must useprudent judgment when approving exceptions to the policies of this order.4.0 TRANSFORMERS and REACTORSDo not re-energize until a full assessment and visual inspection by qualified personnel has takenplace.For transformer fault when customers are de-energized, one reclose is permitted after: Visual inspection confirms that the gas relay does not have any gas in it and Visual inspection of the transformer and all other equipment in the protection zone both show nofaults and analysis of relay targets indicate that transformer is o.k. i.e. no 87 or gas relay trip andtrip caused by 51 relay. If the cause of trip out is not clear then the manager responsible for maintaining the equipmentshould be contacted for adviceSimilarly, when customers are de-energized, one reclose is permitted when one of the followingoccurs: The fault was external to the transformer and has been cleared.

OO 1T-29AEffective: 26 February 2014Page 3 of 8The protection has misoperated.The trip was inadvertently initiated by staff working in the substation or on the protection scheme.Where transformers are equipped with automatic ground switches and motor operated disconnects,the manual reclose must be delayed long enough for this equipment to completely open which may beindicated by status indication or just an alarm.For reactors one reclose is permitted if the reactor circuit breaker has tripped with an associated linetrip as part of the line protection operation. Station alarms must be assessed and if it is clear thereactor protection has not operated the reactor can be re-energized. It is expected that a faultedreactor connected to a line would have opened the reactor disconnect or the associated lockout relaywill hold a trip on the reactor circuit breakers.After an earthquake if only a gas relay has operated and there is no other visible damage to thetransformer or reactor, then it is allowed to return the transformer or reactor to service without anyother test.4.1 "The following is required for feeders emanating from substations that are supplied bya transformer protected by high voltage (HV) fuses:”4.1.1 The transformer and the substation equipment will be visually inspected beforereplacing HV fuses.4.1.2 Feeders will be re-energized without a prior patrol provided all the following criteriaare met:* the source transformer is wound delta-wye* only one fuse is blown on the transformer* all three phases of the feeder recloser or breaker are found closed.Under this condition, all three phase are energized but two phases are at half voltage.The fault has cleared.4.1.3 Feeders must be patrolled and/or sectionalized prior to re-energizing after replacingthe source transformer HV fuses when any of these conditions occur:* the source transformer is not wound delta-wye* more than one HV fuse is found blown* the feeder breaker/recloser is found to have at least one phase open.In this circumstance, at least one phase of the feeder is de-energized and apatrol/sectionalizing is required to verify the fault has been cleared.5.0 GENERATORS, LEAD SHAFTS, AND SYNCHRONOUS CONDENSERSDo not re-energize until the cause of the tripout has been investigated and the unit or lead shaftdeclared ready for service by the manager responsible for that equipment or his/her delegate.After a generation shedding operation this does not apply.6.0 TRANSMISSION LINES6.1 Transmission Lines with Automatic Ground SwitchesWhere lines are equipped with automatic ground switches and motor-operated disconnects toclear faulted apparatus, the manual reclose must be delayed long enough for this equipmentto completely open which may be indicated by status indication or just an alarm.6.2 Transmission Lines Terminating in SF6 BusIf there is an SF6 bus fault detected at the line end, the SF6 bus lockout relay will blockclosing at the faulted bus and will send a transfer trip to the other end of the line. If the bus

OO 1T-29AEffective: 26 February 2014Page 4 of 8lockout relay has operated at the SF6 end, then do not re-energize the line even with the SF6line disconnect switch open until the cause of the tripout is investigated by qualified personnel.6.3 Overhead Transmission LinesOne manual reclose should generally be attempted promptly, even after unsuccessful autoreclosing.This means two recloses will normally be attempted if the line has automaticreclosing capability.The exception being when the fire hazard is rated high to extreme and in the absence of alightning storm, only one reclose maximum (either automatic or manual) should be attempted.This is to avoid a risk of starting a forest fire.After this, do not re-energize again until the cause of the tripout is investigated or the circuit issectionalized or a patrol is completed.After an unsuccessful manual reclose attempt, restoring power to the majority of thecustomers should be attempted by sectionalizing the faulted part of the circuit. SEL relayinformation should be used to help sectionalize a faulted section. If the Control Center hascontrol over motor operated disconnect switches or breakers, then they should be openedand one reclose attempted after sectionalizing. If the reclose is unsuccessful, then a reclosecan be attempted from the other side of the line.When a manual reclose is initiated promptly either following the initial trip or an unsuccessfulautomatic reclose, it is not necessary to unload the circuit prior to energizing the circuit inorder to restore the customers as quickly as possible.6.4 Transmission Lines Comprising Overhead and Underground CableWhere a transmission circuit is comprised of both underground cable and overhead sectionsand the cable is fluid-filled:Do not re-energize the circuit until the cause of the tripout has been determined.In the case of tripout is known or occur during unusual weather disturbances, such aslightning or windstorm, which may have faulted the overhead section, one manual reclosemay be attempted, if it is judged safe to do so (see section 6.6). If the cause of trip out isnot clear then the manager responsible for maintaining the equipment should becontacted for advice.Apply the normal reclosing policy listed in section 6.3, if the fluid-filled cable length is lessthan 50% of the line length.Where a transmission circuit is comprised of both underground cable and overhead sectionsand the cable is non fluid-filled, one reclosing should be attempted.All Transmission cables are fluid-filled, except those listed below:LIST OF NON FLUID-FILLED CABLES* 1L18 is High Pressure Gas-FilledNewell 69 kV Circuits60L6060L6760L3660L35Chilliwack Circuits60L9360L94Morgan Creek60L73Como Lake60L01

OO 1T-29AEffective: 26 February 2014Page 7 of 8Appendix AList of Transmission Lines NOT Permitted to RecloseAOR Circuit Station RemarksGrid 3Grid 32L202L31CSQ-MPTCSQ-MUR100% cable100% cableGrid 3 2L32 CSQ-HPN >50% oil filled cableGrid 3 2L33 CSQ-HPN 100% cableGrid 3Grid 32L442L45SPG-MPTCSN-SPG100% cable100% cableGrid 3 2L53 MAN-MUR 100% cableGrid 3 2L55 MAN-CSN 100% cableGrid 3 2L64 SPG-KI2 >50% oil filled cableGrid 3 60L50 MUR-DGR 100% cableGrid 3 60L51 MUR-DGR 100% cableGrid 3 60L52 MUR-DGR 100% cableGrid 3 60L53 MUR-DGR 100% cableGrid 2 2L143 HSY-ESQ 100% oil filled cableGrid 2 2L145 PIK -ESQ 58% oil filled cable. Reclose only when there is a customeroutage and no oil pressure alarms at BNT & ESQGrid 2Grid 22L1462L29HSY-GOWSAY-PSY100% oil filled cableNo reclose without TMGP Generator System AuthoritypermissionNCCGrid 1 60L342 CRD-PGP 100% oil filled cableGrid 1 60L343 CRD-PGP 50% oil filled cableGrid 1 60L345 CRD-HSK 50% cableGrid 1 60L346 CRD-ICP 100% oil filled cableGrid 1 60L347 CRD-ICP 100% oil filled cable

OO 1T-29AEffective: 26 February 2014Page 8 of 8Appendix BList of Transmission Lines Permitted to Reclose Only OnceRegion Circuit Station RemarksLower Mainland 60L1 BND-COK Distribution UnderbuildLower Mainland 60L2 COK-SFL Distribution UnderbuildLower Mainland 60L3 COK-MRG-HNY Distribution UnderbuildLower Mainland 60L5 LB1-SHL Distribution UnderbuildLower Mainland 60L7 MLN-BAL-PKL-WNK-RUS Distribution UnderbuildLower Mainland 60L8 MLN-BAL-PKL-RUS Distribution UnderbuildLower Mainland 60L10 KEN-WAH-HOP-SZM-BBR Distribution UnderbuildLower Mainland 60L11 IOC-SFU-BND Distribution UnderbuildLower Mainland 60L15 SFL-RUS Distribution UnderbuildLower Mainland 60L17 BND-COK Distribution UnderbuildLower Mainland 60L18 COK-CQM-HNY Distribution UnderbuildLower Mainland 60L23 SFL-HNY Distribution UnderbuildLower Mainland 60L26 BND-COK Distribution UnderbuildLower Mainland 60L54 BND-SFU-PCP Distribution UnderbuildLower Mainland 60L93 ALZ-CHK-KEN-WHP-WAH Distribution UnderbuildLower Mainland 60L94 ALZ-CHK Distribution UnderbuildVancouver Island 60L128 PVO-LCW Distribution UnderbuildVancouver Island 60L83 KTG-SNY Distribution UnderbuildNorthern Region 60L341 GLN-FSR-FSS Distribution UnderbuildNorthern Region 60L358 BVY-IPR Distribution UnderbuildNorthern Region 60L339 BLW Distribution UnderbuildNorthern Region 60L337 WSN Distribution UnderbuildSouthern Interior 60L210 MON-NDR-NAK Distribution Underbuild