/ UK Power Networks / DSR 01 002
v4.0

HV System Operations

Owner
Name / Peter Vujanic
Title / Head of Health and Safety
Signature
Date / 01 May 2016
Authoriser
Name / Dudley Sparks
Title / Operational Safety Manager
Signature
Date / 01 May 2016

This document forms part of the UK Power Networks Integrated Management System and compliance with its requirements is mandatory. Departure from these requirements may only be taken with the written approval of the above authoriser.

Revision Record
Version number / 4.0 / What has changed?
The following sections are new or have been modified: 8.2, 8.5, 8.6, 8.10, 8.13.1, 8.13.2, 8.13.5, 8.13.9, 8.22 & 9.1.
Why has it changed?
Incorporating legacy procedures
Date published / 01/05/2016
Next review date / 01/05/2019
Prepared by / N Saunders and R Hembling
Version number / 3.0 / What has changed?
The following sections are new or have been modified: 8.5, 8.6, 8.12, 8.15, 8.19 & 8.20.
Why has it changed?
Incorporating legacy procedures
Date published / 17/3/2014
Next review date / 17/3/2017
Prepared by / N Saunders
Version number / 2.0 / What has changed?
No changes
Why has it changed?
Date published / 21/10/2013
Next review date / 09/04/2014
Prepared by / N Saunders
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Contents

1.0Introduction and Purpose

2.0Scope

3.0Objective

4.0References

5.0Definitions

6.0Responsibilities

7.0Records

8.0Process Detail

9.0Appendices

1.0Introduction and Purpose

This procedure sets out fundamental rules and guidance for switching and operations on all High Voltage networks up to and including 132kV that are owned or operated by UK Power Networks.

2.0Scope

This procedure is supplementary to the Distribution Safety Rules, and does not authorise any departure from them, except where specifically stated. It should be read in conjunction with those rules.

This procedure details how to obtain permission to operate the HV network, and responsibilities and safety instructions for those who do operate the HV network.

It includes

  • Pre-planning switching operations
  • Use of switching schedules
  • Basic Rules for switching operations
  • Communications between Control and Field staff
  • Switching Across Operational Boundaries
  • Isolation & Earthing
  • Application of Circuit Main Earths
  • Changing HV fuses submerged in oil
  • Special switching procedures in accordance with DSR rule 1.6
  • Switchgear Interlocks
  • Use of Insulated Rods in the Vicinity of Overhead Lines

3.0Objective

To supplement the UK Power Networks Distribution Safety Rules and provide a process for UK Power Networks with regard to switching operations.

4.0References

DSRs / Distribution Safety Rules
DSR 01 009 / Operation of SF6 Switchgear
DSR 01 013 / Safety Documents
DSR 01 015 / Identification of Points of Work
HSS 01 105 / Putting People to Work
HSS 40 023 / Energisation of Networks Following Faults and Emergencies
HSS 40 048 / Investigation and Management of AVC Failures
HSS 40 047 / Use of Portable Earths
HSS 40 042 / HV Switching – Remote Operating Devices
NOP 50 001 / Pre and Post Outage Checks for EHV Networks
(Grid & Primary Substations)
GOP 13 / Generic Task Risk Assessment HV & EHV Underground Switching
GOP 17 / Generic Task Risk Assessment HV & EHV Overhead Switching

5.0Definitions

Confidence Switching / Opening and closing of a circuit breaker by electrical means either on site or remotely and, where possible, recording of circuit breaker operating times via a remote terminal unit
Distribution System / The complete electrical system for which UK Power Networks has responsibility in one or more of the following areas: Control, Operations, Maintenance and/or construction
DSRs / Distribution Safety Rules
Field Control / Where control of an agreed section of network is passed by the Control Centre to a Senior Authorised Person, who is authorised to take Field Control on site.
LV Switching / Low voltage operations carried out on the network operating at or below 1000V.
PrimaryHV Network / That part of the HV network supplying primary substations
Primary Substation / A substation forming part of the HV network where the transformer output is above 1kV, and is not a secondary substation
RTU / Remote Terminal Unit. A generic name for the device used to remotely control plant at a substation. It is located at the substation and contains a modem and control unit.
Secondary HV Network / That part of the HV network supplying secondary substations
Secondary Substation / A substation forming part of the HV network where the transformer output is at or below 1kV, or the input voltage is 11kV or less.
Sequence Of Operations / Two or more switching items carried out in succession without reference back to the appropriate Control Engineer between operations.
Substation / Any premises or that part of any premises, in which electrical energy is transformed, converted or controlled.
Switching Party / Two or more appropriately authorised persons, at separate locations, acting under the direction of the Person in Charge, who jointly execute an approved Sequence of Operations within a switching schedule.
Switching Schedule / A check list and record of operations required to safely carry out a specified operational objective. It is also the Control Engineer's notice of the proposals for a sequence of switching

6.0Responsibilities

In addition to the requirements of DSR 9.5, the Control Engineer is responsible for

  1. Directing and approving running arrangements of the Distribution System for load flow and short circuit level control and in accordance, where appropriate, with agreements with other interested parties.
  2. Deciding, in discussion with other interested parties, whether system conditions will allow pre-arranged or additional outages of apparatus or circuits to take place.
  3. Making system arrangements for the release of High Voltage Apparatus.
  4. Pre-checking, when necessary, the contents of switching schedules.
  5. Approving switching schedules.
  6. Consenting to the implementation of a switching schedule and the operations contained in it.
  7. Carrying out HV Switching operations by remote control.
  8. Maintaining continuity and security of supplies on the Distribution System together with control of equipment.
  9. Agree system electrical safety before consenting to the issue of a Safety Document.
  10. Allowing the start, and recording the times, of switching operations.
  11. Ensuring that the name of the Person in Charge of a Switching Party is stated on the switching schedule
  12. Ensuring maps and other displays are dressed where necessary with the appropriate indicators at the correct time.
  13. Ensuring that the engineer who takes over the next shift is fully briefed with the operating conditions of the system coming under their control.

All staff operating on the distribution system are responsible for;

  1. Working in accordance with the Distribution Safety Rules, this procedure, and any additional procedures, bulletins, restrictions, special operating conditions and instructions issued by or on behalf of the director of Safety, Strategy and Support Services.
  2. Ensuring that they have the correct level of authorisation for any operations they are carrying out on the Distribution System including issuing safety documents. Note that authorisation gained in UK Power Networks is regional and therefore may not apply to more than one region.
  3. Providing appropriate supervision for field operators under training.
  4. Ensuring that they possess a network diagram for any network that they are operating on, if available.
  5. Carrying out an operation or sequence of operations to the instructions of the Control Engineer or when used, the direction of the Person in Charge of the Switching Party.
  6. Ensuring that persons receiving safety documents are competent to do so.
  7. Carrying out safety procedures as required by UK Power Networks.
  8. Ensuring the security of operational keys.

The Senior Authorised Person or Authorised Person in charge of work is responsible for ensuring a safe zone of work has been provided to avoid danger from the electrical network.

7.0Records

The HV diagram in the Control Centre shall be dressed to reflect the current configuration of the distribution network and with any other relevant details (e.g. faulty apparatus, safety documents). This shall include reference to any part of the network that has been transferred to Field Control (see section 8.8 below)

The recording of switching operations is detailed in section 8.9 below.

Switching Schedules and related safety documents shall be retained for 12 months, and be available for scrutiny.

Records shall be maintained of the authorisation level of all people who have access to or operate on the Distribution Network.

8.0Process Detail

8.1General Rules for Switching

In addition to the requirements of DSR section 3.5, the following rules shall apply when switching

  1. The Control Engineer’s consent shall be obtained immediately before commencing a single operation, or a Sequence of Operations.

An exception to this rule is where emergency switching has to take place: an authorised person may carry out or instruct switching to be undertaken, that has not been pre-approved by a Control Engineer, where he believes that such action is necessary to remove a danger to life. Such actions shall be limited to the removal of the dangerous condition from the distribution system, and must be reported to the Control Engineer as soon as possible.

  1. If you make an error whilst switching, on no account attempt to rectify the error by another operation. The Control Engineer shall be contacted before any further switching takes place.

8.2General Guidance for Switching

  1. Fully understand and obey the Distribution Safety Rules. They are drawn up for your protection and the protection of those working with you.
  2. Use the switching hierarchy listed in DSR rule 3.5.7.

Note: Operation via a relay is not recommended due to the possibility of intertripping, unless it is part of relay testing

  1. Do not trust your memory; consult your written instruction immediately before carrying out any operation.
  2. Understand the equipment that you are required to operate. Always ask if in doubt and do not experiment with live switchgear.
  3. Always check that you are at the right location. If the substation name label is missing or illegible, it may be possible to identify the substation by checking all switchgear labels.
  4. Make a visual inspection of all the switchgear before carrying out any switching operations (including the integrity of the substation earthing). If the switchgear shows any signs of distress, notify the Control Engineer immediately and arrange for a detailed examination to be made.
  5. Check the position of any switch that you are about to operate. Is it in the position (closed, open or earthed) you expect from your instructions? If not, find out why.
  6. Check the title of any circuit and the function of the operating handle twice before operating. If in doubt, ask.
  7. Wherever reasonably practicable, use a Remote Operating Device for oil filled switchgear (refer to HSS 40 042HV Switching Remote Operating Devices)
  8. Before operating a switch that is fitted with a Reverse Operation Delay Handle, ensure that the handle is working properly. Do not attempt to operate the switch without the correct handle.
  9. During any switching operations, only those persons necessary for conducting the operations should be within the vicinity of the switchgear.
  10. When switching, only remove the padlock(s) necessary to allow the current operation. Immediately lock it again when that operation is complete.
  11. Operate switches without hesitation; you may be closing onto a short circuit. If a circuit breaker trips immediately on closing, establish the reason before attempting to reclose.
  12. Immediately after completing an operation, look at the switch position indicator to check that you have in fact performed the operation intended in accordance with your instructions. Any mal-operation shall be reported to the Control Engineer immediately.
  13. Never run within a substation or enclosure whilst switching. Pause and think before you act. All actions should be deliberate, never impulsive.
  14. All relay flag indicators that have operated must be correctly recorded before re-setting.
  15. When leaving a substation unattended, make sure it is securely locked.

8.3Use of SwitchingSchedules for planned Switching

  • Where a series of pre-planned operations are to be carried out then a switching schedule shall be prepared and shall be approved by a Control Engineer. In exceptional circumstances the Control Engineer may agree that planned work can proceed by direct instruction if it is operationally advantageous to do so.

Where fault repairs such as switchgear replacement can be pre-planned, a switching schedule should be prepared in the normal way.

Due to the relative simplicity of the operation, a pre-approved switching schedule will not be required for the “confidence” switching of circuit breakers or switches which are carried out by Control Engineers remotely, using telecontrol.

  • All outages affecting the Primary network shall be subject to appropriate planning and approval by Outage Planning - see section 8.5 below. The switching schedule submitted from the field should normally be limited to the items required to achieve the final isolation, application of circuit main earths and the issue of safety documents, but can be complete for simple outages such as transformer feeders.

Other switching operations, to configure the Primary network for the outage, shall be carried out to the instructions of the Control Engineer, referring to any advice from Outage Planning and the known state of the Primary network.

The schedule will be approved by a Control Engineer and then be available to the originator as an authorised switching log.

If conditions have changed on the day then the switching will become unscheduled and under the discretion of the Control Engineer.

  • For work on the Secondary network the switching schedule should normally include all items required for the planned switching, including configuration of the network and restoration to normal running conditions.
  • The person preparing the switching schedule shall take due regard of system security issues. As far as reasonably practicable the nature of the outage, and the timing, shall aim to minimise the risk to customer supplies.
  • Unusual or high risk outages on the secondary network shall be discussed with the Control Centre before the switching schedule is submitted. Where appropriate, an emergency restoration plan shall be agreed. See section 8.5 below.
  • If HV isolation is necessary for work to be carried out on LV apparatus (e.g. on transformer LV connections) then a HV switching schedule shall be prepared and submitted.
  • Items shall be included on an HV switching schedule to confirm LV isolation, if applicable.
  • A switching schedule shall be submitted by a person authorised to carry out the operations listed in the schedule.

An exception can be made for persons under training to become Authorised Persons. In such cases, the switching schedule shall be counter-signed by a person authorised to carry out the operations listed in the schedule, or in the case of Power On, annotated as checked by the name of the suitably Authorised mentor.

  • The Control Engineer at the relevant voltage level is responsible for approving all switching schedules.
  • A switching schedule shall only be used if it has been approved by a Control Engineer.
  • A switching schedule shall only be used once it has been ascertained by the Control Engineer and all members of the switching party, that all paper copies are the same version as the Control Engineer’s.
  • Approval of a Switching schedule does not signify that the Control Engineer has released the apparatus concerned. Network conditions may have changed since the schedule was approved.
  • No departure or variation from an agreed switching schedule shall be made without the sanction of the Control Engineer. Where changes are agreed, these shall be approved and recorded by the Control Engineer. The Field Operators shall also amend their copies of the switching schedule accordingly.
  • The Authorised Person, or in the case of a Switching Party (see section 8.7 below), the Person in Charge, and the Control Engineer shall record, on their copies of the switching schedule, the date and time that consent for an operation or a sequence of operations was given. The Authorised Person, or in the case of a Switching Party, the Person in charge, will record on his copy the date and time of each completed operation detailed in the switching schedule.

8.4Unplanned Switching

For unplanned (normally fault) switching, the following procedure shall be used.

  • The Control Engineer shall raise an unplanned (also known as On Demand) switching log, which shall be allocated a switching schedule number. This number shall be communicated to all field operators carrying out switching operations on the incident.
  • Every instruction must be written down and read back in full to the sender to ensure that the message has been accurately received. An exception can be made if customers are off supply and the switching operator is communicating with the Control Engineer directly from the switch that he is instructed to operate, and only a single instruction is to be given. In such circumstances the instruction shall be repeated to the Control Engineer who shall remain in contact with the switching operator until confirmation is given that the operation has been completed.

Once customer supplies have been restored, further operations to complete repairs and restore the network to normal running conditions shall be recorded on the unplanned switching log.

  • The Control Engineer shall record the time of instruction and completion of all operations on the log. This shall include the times that Field Control has been granted and returned to the Control Centre for the relevant section of network.
  • Where switching operations cannot be agreed between the Control Engineer and the switching operator, the Network Manager may take the lead (subject to the requirements of Distribution Safety Rule 1.7).

8.5Contingency Planning

  • The responsibility for co-ordinating the contingency plans on the Primary Network lies with the Outage Planning section in consultation with Field and Control Engineers.
  • On the Secondary network the responsibility for providing the plan will be with the originator of the switching schedule.
  • In both cases copies of the contingency plan will be held in readiness at the Control Centre throughout the planned outage.
  • When there is a risk of trip on any circuit, the work is to be agreed with the Control Engineer before starting
  • Pre and post switching checks on EHV networks (Grid and Primary Substations) shall be carried out in accordance with NOP 50 001.
  • Where it is not possible to complete work and restore the network by the end of the working day, and the circuit could be required in an emergency, the Recipient of the Safety Document shall confirm to the Control Centre the state of the network and the status of safety documents. The safety document shall be returned to a recorded place and shall be collected before work recommences. If there is a need to cancel the safety document the procedure detailed in DSR 01 013 shall be followed.

8.6Sequence of Operations

  • Subject to the consent of the Control Engineer a Sequence of Operations may be carried out by a suitably Authorised Person, or by a Switching Party(Note: this is an Approved variation of DSR rule 3.5).
  • A Sequence of Operations shall be carried out strictly in accordance with the agreed instructions. Field operators may not amend or add to the switching instructions. This includes the position of circuit main earths.
  • If it proves impracticable to carry out any item as agreed, then the sequence of operations shall be stopped and the Control Engineer advised. Any further switching operations shall be to the direct instruction of the Control Engineer.
  • As soon as possible after the Senior Authorised or Authorised Person has carried out all of the operations contained in a sequence of operations, they shall notify the Control Engineer of the time of the last operation in that sequence.
  • The person implementing, or the Person in Charge of co-ordinating a switching schedule, shall establish direct communications with the Control Engineer in the following circumstances as a normal requirement. Or, if this is not possible,at a point agreed between the Control Engineer and Field Operator:

a)Immediately prior to the start, and at the end of, a Sequence of Operations.