SUBJECT HEADING: Switching Programmes ISSUE: 18

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1 SUBJECT: Switchgear/Switching PROCEDURE: S04 SUBJECT HEADING: Switching Programmes ISSUE: 18 DATE: Apr INTRODUCTION 1.1 A written programme of switching operations shall be prepared. This programme shall be endorsed by a Senior Authorised Person and shall be checked and agreed by another Senior Authorised Person. Copies of the programme shall be in the possession of the Authorised Person(s) carrying out the switching and the Control Engineer prior to the switching being carried out. (Switching by National Grid staff shall be control directed). 1.2 A written switching programme is not required for; routine switching; control directed switching (National Grid staff shall normally be control directed); fault restoration; National Grid controlled switching; emergency switching; telecontrol trip timing requests which do not require on site switching; R/C function testing carried out by Control which does not require on site switching; disabling, altering, resetting protection eg auto-reclose when there is no associated plant switching. 2. SWITCHING DEFINITIONS 2.1 Routine Routine switching shall only be undertaken if approved by System Operations. 2.2 Planned Switching carried out using a switching programme prepared and submitted to DSMC at least two working days before operations are to commence. Shorter timescales shall be allowed for emergencies or by prior arrangement with the Control Engineer involved. 2.3 Control Directed Switching authorised by the Control Engineer without the operational engineer being in possession of a switching programme. 2.4 Fault Restoration Control directed switching post fault to restore system supplies/security together with isolation, earthing and on occasions fault location of the faulty section *. NOTE * It is normally practicable to write a switching programme for the subsequent fault repair and re-commissioning together with the restoration to system normal. 2.5 Emergency Switching necessary to make dead a section of the system where life or plant are at risk. Such switching shall be reported to the Control Engineer as soon as practicable after the operation. S04.docx Issue 18 14/04/17 SJS CP606/610 Page 1 of 8

2 3. GENERAL 3.1 A switching programme(s) for a planned outage shall be submitted by only one party. The party responsible for the preparation and submission of a switching programme(s) shall be the party responsible for initiating the work. 3.2 Where planned work is to be initiated by more than one party, the responsibility for the preparation and submission of the switching programme shall be agreed between them. 3.3 All planned LV switching shall be the subject of a switching programme. If it is associated with an HV switching programme then the two programmes shall be cross referenced. 3.4 Switching programme operations shall normally be carried out in strict sequence unless a change in sequence is authorised by the Control Engineer. The Control Engineer may in appropriate cases instruct operations to be carried out simultaneously, by different operators, where such operations do not interact with other operations on the programme. 3.5 Switching programme requirements shall comply with those of the Distribution Safety Rules. 3.6 Where operations are to be carried out at a substation, all switching programmes shall include both the name and the number of the substation entered under the heading Location. 3.7 Once the LV or HV switching programme has been completed, it shall be signed off and field copies sent to System Management, DSMC, Linley House within 10 working days of programme completion. DSMC shall file all completed switching programmes and retain them for inspection for 2 years from the programme date. 4. SWITCHING PROGRAMME NUMBERS All switching programme numbers are issued by System Management at DSMC to the following procedure. 4.1 Staff requiring planned outages on the HV system shall obtain a combined outage/switching programme number from System Management. 4.2 At the start of requesting the outage the requesting engineer shall provide a start and end date, brief circuit/work information, a supply restoration time and an approximate start time. 4.3 Emergency supply interruptions and faults are not subject to this procedure although switching programme numbers for fault repairs shall be issued by DSMC. 5. PRELIMINARY ACTIONS The following are some of the factors which shall be taken into account as necessary, when preparing a switching programme. 5.1 Load flow and system security eg: Check circuit loads and ratings For 132kV outages the following may need to be considered: S04.docx Issue 18 14/04/17 SJS CP606/610 Page 2 of 8

3 (a) (b) (c) Circuits from supergrid substations with split 132kV busbar running arrangements, or Circuits which form part of multi circuit 132kV supplies to a 132kV substation, or A section of supergrid substation 132kV busbar Confirm with System Management, the required supergrid 132kV busbar running arrangements necessary to provide maximum security during the proposed outage. 5.2 System paralleling considerations - phase angle; tap change control arrangements. Refer to CP608 Section 9 for paralleling fault level control actions. 5.3 Fault level in relation to switchgear rating. 5.4 Protection settings - sensitive earth fault protection. 5.5 Parallel operation of private generation. 5.6 Availability and rating of LV backfeed. 5.7 Warning to consumers of temporary disconnection. 5.8 Type of switchgear involved Operational limitations Test bushings Earthing gear Actuators fitted? 5.9 Method of phasing out Number of control zones involved Number of operating engineers required - use of telecontrol switching Geographical location of switching points Automation Schemes or Remote Control of switchgear. The operating procedures for Switchgear Actuators are to be found in CP Private HV systems: Inform customer of proposed switching when security of supply is compromised Verify operational state of customers private switchgear, ie incomers and bus section closed. 6. HV SWITCHING PROGRAMMES 6.1 HV switching programmes shall be prepared using CRMS system, or the computerised paper equivalent, or paper forms ENW/657 and ENW/658. S04.docx Issue 18 14/04/17 SJS CP606/610 Page 3 of 8

4 6.2 Switching programmes can be printed and faxed to DSMC. The computerised paper equivalent can be digitally signed by endorser, ed to the approver, who will digitally sign the programme and then convert it to a pdf document and it to the DSMC Switching Programme inbox (DSMCSWPR@enwl.co.uk), to the endorser and all other operators Where practicable and necessary switching programmes shall be prepared to completely cover all stages of an outage ie: System rearrangement Safety switching to isolate and earth the section to be released for work. This includes switching between Electricity North West control boundaries Issue and cancellation of safety documents Switching to re-energise the outage section Switching to restore the system to normal. 6.4 Where, however, the duration of an outage is excessive or where due to practical consideration the progress of the outage is uncertain, separate switching programmes can be prepared to cover: Initial three stages in Final two stages in When the operation is to be carried out at a substation, both the name and the number of the substation shall be entered under the heading Location on the switching programme. 6.6 At the start of a planned outage, the first operation shall be to confirm planned supply interruption control sheet TMS number..approved and customers carded. 6.7 Each operation on a switching programme shall be separately itemised. Visual confirmation items such as checking the operational state of switchgear and EFIs shall be written as an operation on the switching programme, this requirement does not apply to routine planned substation inspections that are carried out as part of a pre-planned maintenance regime. The list below shows examples of approved switching programme text Open or Close CB Isolate CB Select CB earth position Open or Close isolator Open or Close earth switch Prove feeder spouts dead Withdraw or replace VT Apply or remove portable earth Render inoperative or restore tripping S04.docx Issue 18 14/04/17 SJS CP606/610 Page 4 of 8

5 LV paralleling Issue or cancellation of safety documents Remove/replace trip links Confirm open from earth Confirm oil switch open Confirm circuit breaker tripped Confirm EFI operated 6.8 The words "Apply Safety Lock and Post Caution Notice" or SL & CN shall be added to the above items where applicable. 6.9 Under a Sanction for Test (SFT) 7.2 of the safety rules permits the removal and replacement of CMEs as necessary However, it is recognised that when testing a circuit including switchgear at an intermediate substation or substations, that some switching is necessary during the testing: a) To ensure the whole system, within the specified points of isolation, is tested, and b). To change the state of some switches to enable a full test to be carried out eg opening of a transformer switchfuse or circuit breaker This limited switching may be carried out under the SFT, providing that no switching is done outside the circuit limits stated in the SFT. The circuit under test and hence under the SFT shall be the minimum consistent with the work being carried out It is important to remember that following the cancellation of the SFT, confirmation items detailing the state of all switches involved in the testing shall be listed before any further switching or work is carried out on the programme Testing, under a SFT, shall be carried out at the switchgear from where it is proposed to re-energise the circuit, except where it is impracticable (eg no available test bushings or test access) Where testing involves the primary conductors, the SFT shall include the following additional details under Brief description of testing to be carried out : a) The test bushing serial number (where test bushings are used) b) Integral test bushings (were test bushings are part of the switchgear) c) Direct connection (where testing is performed with direct connection to busbars or exposed conductors) 6.10 LV operations shall be written on a separately numbered LV programme sheet. Reference can then be made in the HV programme to the completion of a group of LV items. Alternatively, when the number of LV operations is small, they can be included on the HV programme. S04.docx Issue 18 14/04/17 SJS CP606/610 Page 5 of 8

6 6.11 If the HV system is to be amended or extended, then diagrams showing the existing and proposed arrangements, including intermediate stages if appropriate, shall be attached to the switching programme. Action shall also be taken to update operational diagrams Where the HV system is to be amended in such a way that existing circuit labelling is affected (e.g. new ground mounted substation, PMT or ABS) then the switchgear labels at remote ends will require replacing in line with CP615. Installation of labels on the new switchgear and replacement of labels on remote end switchgear shall be recorded as separate operations on the switching programme. In addition the wording of the labels shall be recorded on the System Amendment Diagram at both new and existing switchgear locations The degree of Authorisation of the Senior Authorised Persons responsible for the endorsement and approval of a switching programme shall be appropriate to the content of the switching programme Where provision exists to extend the entries on a switching programme, the range of numbers checked shall be entered against the endorsement and approval signatures When a programme is prepared to cover the first three stages mentioned in 6.2 above then: Separate switching programme sheets shall be used to contain a) Safety switching together with the initial safety document issue, and b) System re-arrangement switching If following either the issue of initial safety documentation or system arrangement switching the sequence of work is uncertain, blank sheets shall be appended to record any programme entries subsequently agreed. The blank sheet(s) shall be numbered in sequence and its (their) existence recorded in the statement of sheet numbers on the 'Programme of Switching Operations' front sheet Where provision is made to include additional items in the run of a programme, a significant gap shall be left in the numbering sequence to allow for subsequent item insertion If following the cancellation of the initial safety document(s) an unforeseen change in the work requirement is identified, when agreed, outstanding switching programme entries shall be cancelled and a new switching programme prepared. The new programme shall be cross referenced to the old programme When advantage is taken of the relaxation permitted in , the following conventions shall apply: Switching programme entries for both the issue and cancellation of additional safety documents shall be agreed and entered onto the programme at the time of request. NOTE: Switching programmes shall cater for the cancellation of all safety documents associated with points of isolation and earthing before such points are changed Additional programme entries shall be recorded on both the Control Engineer s 'Master' copy and the requesting Senior Authorised Persons and if appropriate Operational Engineer s copies. The entry numbers shall be the next available numbers, in sequence, on the Control Engineer s 'Master' copy. S04.docx Issue 18 14/04/17 SJS CP606/610 Page 6 of 8

7 6.17 When approved, the programme shall be adhered to unless circumstances change, in which case, if time permits, a revised programme shall be prepared. In all other cases, it is permissible to change the programme by alteration of individual items provided that two SAPs one of who shall be the Control Engineer (or Field Control Engineer if the changes are within the Field Control boundaries), agree the changes and initial the alterations on their copies of the programme. Consideration shall be given to suspending a switching programme where there are too many alterations as this could cause difficulty reading, misunderstanding and sequencing issues. It is important before the changes are agreed that a discussion takes place between the Control Engineer (or Field Control Engineer) and field engineers as to the reason for the changes and that all parties understand any changes. The field engineers shall write down the alterations and repeat them in full to the sender to ensure that the amendment has been accurately received. They shall ensure that all other copies of the programme are amended This procedure also applies if an error is found on a programme A copy of the initial switching programme or any continuation programme shall be available at DSMC at least two working days before the operations are to commence. Shorter timescales shall be allowed in emergency situations or where there is prior agreement with the Control Engineer involved Where switching programmes are used to control switching in more than one control boundary, operations under the control of each Control Engineer(s) shall be clearly indicated Confirmation of the operational state of HV customers private switchgear shall be written as items on the switching programme, ie incomers closed, bus section closed At 33kV and 132kV exposed conductor sites, following a sequence of application or removal of portable earths, confirmation items shall be added to the HV switching programme to confirm that portable earthing rod heads have been locked in an approved metal box. (See Procedure S41) 7. LV SWITCHING PROGRAMMES 7.1 LV switching programmes shall be prepared by a person who is authorised for LV switching, 7.2 When the operation is to be carried out at a substation both the name and the number of the substation shall be entered under the heading Location on the switching programme. 7.3 An LV switching programme register shall be maintained by System Management at DSMC. All LV switching programmes shall be entered in this register and given a unique number, which shall be sequential within the calendar year. 7.4 If the LV switching programme is associated with an HV switching programme, then the two programmes shall be cross-referenced. Alternatively, when the number of LV operations is small, they can form part of the HV programme. 8. DOCUMENTS REFERENCED Distribution Safety Rules CP608 - System Control CP630 - Operating Procedures for Switchgear Actuators S04.docx Issue 18 14/04/17 SJS CP606/610 Page 7 of 8

8 CP606 - Operations Manual Procedure S41 CP615-Substaion, Circuit and Plant Identification. 9. KEYWORDS Control; LV; Operation; Outage; Safety Rules. S04.docx Issue 18 14/04/17 SJS CP606/610 Page 8 of 8

SYNCHRONISING AND VOLTAGE SELECTION

SYNCHRONISING AND VOLTAGE SELECTION This document is for Relevant Electrical Standards document only. Disclaimer NGG and NGET or their agents, servants or contractors do not accept any liability for any