BC HYDRO REAL TIME OPERATIONS OPERATING ORDER 1T-18

Transcription

1 BC HYDRO REAL TIME OPERATIONS OPERATING ORDER 1T-18 LIVE LINE PERMITS, ASSURANCE OF NO RECLOSE PERMITS AND CAUTION TAGS Supersedes OO 1T-18 issued 13 October 2010 Review Year: 2019 Original signed by: APPROVED BY: Paul Choudhury General Manager Real Time Operations Denotes Revision Distribution: In addition to SOO distribution list add LOO(D) Distribution-LM, LOO(D) Distribution NI, LOO(D) Distribution SI, and LOO(D) Distribution - VI

2 Page 2 of GENERAL The purpose of this operating order is to outline procedures relating to the use of Live Line and Assurance of No Reclose Permits and caution tags. 2.0 LIVE LINE PERMITS 2.1 Live Line Permits (LLPs) will only be used for live line work. When dealing with the BC Hydro Control Centre, this can be referred to as a LLP or Live Line Permit. By definition, live line work includes: a) Work with insulated tools contacting energized conductors, but where all parts of the worker s body, including uninsulated tools, are outside the Normal Limits of Approach (SPR Table 401.1, Column 2). b) Work similar to (a) where the workers and uninsulated tools come up to the Absolute Limits of Approach (SPR Table 401.1, Column 1) for brief, planned operations. c) Work where approved live line tools and equipment shall be used to remove any trees (or portions thereof) which are within normal limits of approach to energized or deenergized high voltage lines (SPR rule (c)). d) High pressure water jet cleaning of insulators which support energized conductors. e) Bare hand work where workers are bonded to the conductor. See OO 1T-30 for specific requirements related to Barehand work. f) Whenever there is contact, or possibility of contact, between vegetation growth and an energized high voltage line (SPR rule (b)). g) Cable manhole inspection. h) Rubber glove work. 2.2 LLPs will not normally be required for application or removal of hot taps (SPR 415.1(a)). 2.3 Before issuing an LLP, arrangements must be made to prevent re-energizing of the circuit or apparatus unless the circuit is de-energized. (NOTE: There is no requirement to block auto reclosing if feeder/line is de-energized) Where facilities exist, Live Line protection mode on substation feeder circuit breakers will also be placed in the ON position to enable low set instantaneous, fast trip protection. When in the Live Line protection mode, both the 1200 A phase and 1200 A ground instantaneous elements of the protection are enabled. With the Live Line protection mode enabled, any auto-reclosing associated with feeder protection will be disabled. 2.4 If a circuit or apparatus on which a LLP is in effect is tripped by its own protective relaying, it will not be re-energized until the permit holder has been contacted.

3 Page 3 of Section 2.5 does not apply to Barehand work. See OO 1T-30. When a LLP is in effect and a circuit or apparatus is de-energized by other than its own protective relaying, it is not necessary to contact the permit holder before re-energizing the circuit (SPR 423.5). For example, a) If a transmission line servicing a substation trips out or is deliberately de-energized by the operator while there are one or more LLPs issued on the substation feeders, the transmission line may be re-energized without reference to the permit holder(s). b) When there is a system disturbance with widespread under-frequency load shedding, the circuits may be re-energized without reference to the Live Line Permit holders. c) If a Transmission line crew is working on a de-energized transmission circuit with a live line permit (LLP) in effect, the permit holder must be contacted before re-energizing the circuit. 2.6 LLPs should not be withheld or withdrawn because of routine switching on the power system. The tools and procedures used in Live Line work have been designed to provide safe working conditions including allowances for switching surges and surges occurring as a result of fault conditions. 2.7 When an LLP is in effect on a distribution feeder, the feeder will not be paralleled with any other feeder without first notifying the permit holder (see SPR 423.6). Most transmission lines have protective relaying which is designed to allow normal parallel line operation; any exceptions will be stated in local operating orders. When paralleling lines by closing line disconnects, the no-reclose restrictions must apply to both lines if an LLP is in effect on either line. 2.8 Portions of trees encroaching on the Absolute Limits of Approach for transmission lines (60 kv and above) must be removed with the circuit de-energized and personal protective grounds applied. The exception to this is when the work is carried out from an insulated aerial device using live line tools. (SPR 405.2(d)). 3.0 ASSURANCE OF NO RECLOSE PERMITS When dealing with the BC Hydro Control Centre, this can be referred to as an ANR, ANRP or Assurance of No Reclose. 3.1 Assurance of No Reclose (ANR) Permits are issued for tree trimming in the proximity of an energized line or apparatus (where the worker is between the general limits of approach defined in OH&S Part Table 19-1 and the closer limits defined in OH&S Part Table 19-3). 3.2 Where an Assurance of No Reclose Permit is in place, procedures 2.3, 2.4, 2.5, 2.6, and 2.8 apply with Assurance of No Reclose substituted in place of LLP. 3.3 Assurance of No Reclose Permits may be applied for station civil work and blasting, work on tower footings, removing tops of trees inside limits of approach with a shotgun, danger tree removal with a Feller Buncher, etc.

4 Page 4 of CAUTION TAGS 4.1 Caution Tags may be used as information tags to highlight unusual conditions which affect the normal operation of equipment. 4.2 Caution Tags will not be applied to a device that is used to support work where, should the device be operated, an unsafe condition could result. 4.3 All Caution Tags placed in the SCADA must be supported with a corresponding CROW reference (UC or event) or operating orders, except for Caution Tags applied as part of a SPG on transformers, voltage regulators and shunt reactors which shall be listed on the SPG form. 4.4 The PIC may tag Level 1 to 4 devices with Caution Tags on the mimic. 4.5 The PIC may agree to placement of Caution Tags on Level 1 to 4 devices in the field only when equipment is defective. 4.6 The PIC may direct the field worker to place Caution Tags on state switch of transformers, voltage regulators, shunt reactors, control switch of auto change over scheme, tap changer control etc. 4.7 Some of the Caution Tag examples are disconnect is stiff to open, motor is burnt out or disconnect trip coil is burnt out, locked in closed position, SS automatic transfer does not work (require manual transfer), etc. 4.8 If the PIC has any concerns as to how the work is planned then the matter must be referred to an RTO System Control Manager (SCM) for clarification and resolution. 5.0 COMMUNICATIONS WITH CONTROL CENTRE AND REQUEST TO DE-ENERGIZE: 5.1 Persons holding Live Line Permits or Assurance of No Reclose Permits must be in radio/ telephone contact with the BC Hydro Control Centre at all times. If continuous communication is not possible to maintain, a third reliable person will be required, through whom information can be relayed. 5.2 If the holder of a Live Line Permit or an Assurance of No Reclose Permit causes a tripout, the holder must immediately advise the BC Hydro Control Centre. The circuit should be reenergized if it is safe to do so. The dispatcher should inform the Field Manager so he/she can investigate the incident.

5 Page 5 of Request by Live Line Permit holder to de-energize equipment There may be a requirement for crews to request the PIC to switch out the electrical lines and/or apparatus during Live Line work. If the PIC receives such a request, the PIC will consider it to be urgent and will complete the switching as quickly as possible. The PIC will de-energize the line or apparatus as promptly as possible. The electric system will be adjusted after the line or apparatus is de-energized. If generation shedding or Remedial Action Schemes need to be disarmed, and this can be done quickly, it should be done. Delays in de-energizing the line should not be considered if the request is urgent and is for personnel safety. For all Level I and II transmission lines and / or apparatus, any System Operator (GC,TC,Grid) receiving the request to de-energize will de-energize the line as soon as possible and inform the Transmission Coordinator as soon as practical after the line is deenergized. 6.0 PROCEDURES FOR OBTAINING LIVE LINE PERMITS and ASSURANCE OF NO RECLOSE PERMITS Requests for Live Line Permits and/or Assurance of No Reclose Permits should be pre-scheduled with the BC Hydro Control Centre as follows: 6.1 For Transmission circuits All requests must be entered via the CROW as per outage scheduling OO 1T For Distribution Circuits Please refer to OO 1D Emergency Work Requests for emergency work (motor vehicle accident, wires down, etc.) will be accepted anytime by the BC Hydro Control Centre. 7.0 TAGGING 7.1 "Reclose Off" tags shall be applied to the reclose control in the field (only if the BC Hydro Control Centre does not have supervisory control) and to the PIC s mimic display when reclosing has been turned off (SPR 614.7). 7.2 Tagging of the PIC s mimic display for Assurance of No Reclose Permits will be done using ASSURANCE OF NO RECLOSE PERMIT tags. The tags will be placed as stated in SPR and PSSP 1T-12F (3.1). 7.3 Tagging of the PIC s mimic display for Live Line Permits will be done using LIVE LINE PERMIT tags. The tags will be placed as stated in SPR

6 Page 6 of REVISION HISTORY (This order is also posted on BC Hydro s External website) Revised By Revision Date Summary of Revision DSG 5 November 2007 Added 5.3 request to de-energize equipment during LLP work. AMS 29 April 2010 Updated to remove SCC and ACC terminology DSG/Eric Valois 21 June 2010 BCH/BCTC integration. Caution tag information moved from 1T-13 to 1T-18 DSG 13 September 2010 Revised caution tag section. Protection outage requests will be submitted using no permit required rather than caution tag. DSG 13 October 2010 Updated Section 2.3. DSG 15 October 2010 Updated Section 2.1. MPP,AS,BH, DSM 08 April 2015 Language has been added in Section to instruct operators to enable Live Line protection where available.