Guideline for Creating Disconnection Points and Establishing a Not Electrically Connected Area

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1 Guideline for Creating Disconnection Points and Establishing a Not Document Number: Authorised by: Issue Date: 29 June 2012 Previous Document: 12 February 2010 Principal Authors: J Dohmen Powerlink D Brown Ergon R Gordon Energex. Page 1 of June 2012

2 1.0 Introduction This Guideline has been developed by Powerlink, Ergon Energy and Energex to provide an industry Guideline for the creation of HV Disconnection Points and HV Not Electrically Connected Areas. The provision of this Guideline is to support safe systems of work for activities in a High Voltage electricity network environment. Note: Where practical, preference shall be given to using the Queensland Electricity Entity Procedures for Safe Access to High Voltage Electrical Apparatus (SAHVEA) and Electricity Entity approved procedures 2.0 Scope The requirements of this Guideline apply to all persons intending to establish or are establishing a Not for the purposes of conducting work on or Near previously commissioned Electricity Entity HV Electrical Apparatus. This Guideline shall not be applied to any structures with multiple circuits unless all sources of supply are Disconnected from the network by Disconnection Points and deemed Not Electrically Connected (e.g.: twin circuit HV towers or poles or a combination of circuits on a pole). A Not Notice (the Notice) shall be issued whenever work is being performed in a Not. Only one Notice shall be on issue for any delineated Work Area within a Not. 3.0 Purpose To provide guidelines for the creation and control of an area suitably disconnected from all possible sources of High Voltage supply or energisation. To provide a guideline for establishing a Not for High Voltage Electrical Apparatus by the creation of Disconnection Points and other Control Measures. To ensure that: A safe working environment is achieved when working on or Near High Voltage Electrical Apparatus within a Not, High Voltage Electrical Apparatus within a Not is in an electrically safe condition through the creation of Disconnection Points and the application of earthing. The Queensland Electricity Entity Procedures for Safe Access to High Voltage Electrical Apparatus or Approved High Voltage Live work methods or Approved LV procedures are used to establish a Not. Establishing a Not is conducted in a safe and coordinated manner. Any sources of supply capable of causing inadvertent High Voltage energisation are Disconnected. Switching Coordinators are aware of the status of the High Voltage network. Page 2 of June 2012

3 Data and Records pertaining to Electrical Apparatus are available before a Not is created. All persons and mobile plant and equipment are clear before High Voltage Electrical Apparatus is handed over for re-energisation. The Issue of the Notice has been recorded as a switching operation on an associated Switching Sheet. The return of the Notice is recorded in accordance with Electricity Entity Procedures. 4.0 Defining a Not 4.1 Substations For substation High Voltage Electrical Apparatus, any Not shall be delineated in accordance with the Queensland Electrical Supply Industry Substation Barrier Chart, by the use of the following: A barrier of white tape or white flag bunting with NOT ELECTRICALLY CONNECTED black text erected at a height of approximately 1.3 metres from ground level with a single appropriately sized opening; or A combination of steel mesh panels with a white tape or white flag bunting with NOT ELECTRICALLY CONNECTED black lettering and erected at a height of approximately 1.3 metres from ground level with a single entry point. The barrier shall not be erected within the relevant Exclusion Zone to the Live side of the Disconnection Point. A white sign bearing the words NOT ELECTRICALLY CONNECTED in black text shall be placed at the entrance point to the Work Area. 4.2 Overhead and Underground HV Lines For Overhead and Underground HV Electrical Apparatus, any Not Electrically Connected Area established shall be delineated by: A white sign bearing the words NOT ELECTRICALLY CONNECTED in black text placed at each Disconnection Point on the Not side; or A barrier of white tape or white flag bunting with NOT ELECTRICALLY CONNECTED black text attached around the tower/pole at a height of approximately 1.3 metres from ground level at each Disconnection Point on the Not side; or A combination of both of the above methods Note: Barriers and signs used to delineate the Not shall not be removed or altered without the consent of the Entity Representative and the On Site Supervisor, with all amendments recorded on the Not Notice. Page 3 of June 2012

4 5.0 Establishing a Not A Not can be established provided Disconnection Point/s and Control Measures are established in accordance with this Guideline. An application for work or Live work shall be submitted to the relevant Outage Coordinator in accordance with Electricity Entity requirements for all work to establish a Not Electrically Connected Area on the previously commissioned network. The following shall be recorded on the Notice: a) Description of the HV Electrical Apparatus Not Electrically Connected b) Disconnection Points including any sources of supply which may cause inadvertent HV energisation c) Earthing applied prior to the issue of the Notice d) Barrier and signage details e) Work details and location f) Nearby Live HV/LV g) Additional Earthing applied and removed to limit the rise in potential difference at the Work Area h) Issue, Receipt and Return details (date, Issuer name and signature, Receiver name & signature) i) Workgroup sign on, sign off j) Abnormalities. In addition to the above: a) Any known sources of stored energies and other identified hazards in the Not shall be recorded on the Notice b) A site plan or other appropriate diagram/drawing may be required to identify the Work Area and Disconnection Points to parties associated with the Not. 6.0 Establishing a Disconnection Point High Voltage Electrical Apparatus can be considered to be Not Electrically Connected provided Disconnection Point/s and Control Measures in accordance with this Guideline are established. Where a non-flashover distance is to be utilised in the establishment of a Disconnection Point, it must be assessed and Approved by an appropriately qualified and authorised electrical engineer on a case by case basis. Any such approval shall be documented. NOTE: WHERE A DISCONNECTION POINT IS ESTABLISHED BY MAINTAINING NON- FLASHOVER DISTANCES, IT MAY NOT MAINTAIN OR PROVIDE THE RELEVANT EXCLUSION ZONE CLEARANCES! Page 4 of June 2012

5 To establish a Disconnection Point: a) A section of Conductor shall be removed in accordance with the relevant Electricity Entity s Approved procedure and may include the removal of VT connections as possible energisation points b) Removal of one end of the Conductor is acceptable, in accordance with Approved Electricity Entity procedures, if Approved by an appropriately qualified and authorised electrical engineer. c) Queensland Electricity Entity Procedures for Safe Access to High Voltage Electrical Apparatus [SAHVEA] or Approved HV Live Work methods shall be used. 7.0 Earthing The Electricity Entity shall ensure the Not Electrically Connected HV Electrical Apparatus has initial earthing applied prior to the issue of a Not Notice. The On Site Supervisor shall ensure that while work is in progress, earthing is maintained to suit the progress of work and to limit the rise in potential difference at the Work Area. Only appropriately trained and qualified persons shall apply and remove earths. All Earths placed and removed shall be recorded on the Not Notice. 8.0 Working 8.1 Prior to any work being performed or undertaken in a Not, the Notice shall be issued. When work is being performed within a defined Not, care must be taken to ensure that all personnel are aware of the relevant Exclusion Zone that is required to be maintained by them at all times. Personnel or Mobile Plant are not permitted to pass through barriers used to delineate the Not without the consent of the On Site Supervisor after a valid risk assessment has been performed and all Control Measures identified are in place. All known sources of supply and sources of stored energy in the area shall be identified to the work group during induction processes into the Not. Eg: AC and DC control supplies, Insulating Gas Pressure, Spring Charge. Appropriate Control Measures shall be applied to address these hazards. Page 5 of June 2012

6 8.2 Preparation Prior to providing clearance to issue the Notice, the Switching Co-ordinator shall confirm the Disconnection Points have been created. 8.3 Issue The Notice shall be issued in person and on site by the Entity Representative to the On Site Supervisor. The clearance to issue shall be recorded as an operation on a Switching Sheet. Prior to issuing the Notice to the On Site Supervisor, the Entity Representative shall make themselves aware of all the Control Measures and conditions of the Notice The Entity Representative issuing the Notice shall: o Positively identify the HV Electrical Apparatus recorded on the Notice. Positively identify the Disconnection Points, including any sources of supply which may cause inadvertent HV energisation. Positively identify that initial earthing has been applied and recorded in Section 4 of the Notice. Confirm that a qualified and authorised electrical engineer has assessed and Approved the Disconnection Point/s where non-flashover distance is used or only one end of the conductor has been removed. Any approval documentation shall be made available to the On Site Supervisor. If required, provide additional earthing and record in Section 4 of the Notice. Ensure barriers and signage are erected in accordance with this Guideline. Identify any known sources of stored energies and other hazards. Identify nearby Live HV/LV. Ensure all relevant sections of the Notice have been completed. Brief the On Site Supervisor of the details and conditions of the Notice. Issue the Notice by signing and dating in the appropriate location. Confirm that the On Site Supervisor understands the details and conditions of the Notice. Request the On Site Supervisor to confirm and accept the conditions of the Notice by signing and dating in the appropriate field Transfer of Not Notice Where the On Site Supervisor changes and the person in receipt of the Notice has to transfer the Notice to another On Site Supervisor, this shall be noted on the Notice in the relevant section. The person transferring the Notice shall ensure the new On Site Supervisor is made aware and understands the extent and conditions relating to the Notice. Page 6 of June 2012

7 8.4 Receipt Prior to receiving the Not Notice, the On Site Supervisor shall: Confirm the conditions of the Not Notice are suitable for the work to be performed. Confirm the location of all Disconnection Points as per Section 2 of Notice. Confirm that the initial earthing is in place as per Section 4 of Notice. Confirm barriers and signage erected is adequate. Understand any known hazards or known sources of remaining stored energy as advised by the Entity Representative. Confirm nearby Live HV/LV. Acknowledge the conditions of the Not Notice have been explained and are suitable for the work to be performed by signing on the Not Notice Prior to Work commencing, the On Site Supervisor shall: Brief the work party on the conditions of the Notice. Ensure adequate earthing to limit the rise in potential difference at the Work Area is applied, maintained and recorded in Section 4 of the Notice. Ensure all members of the work party acknowledge the conditions of the Notice by signing on. Indicate any supplementary page(s) for worker Sign On/Off on the related Notice. Attach any related supplementary page(s) for worker Sign On/Off to the Notice. Retain the Notice in a secure but accessible location On Site. 8.5 Return The Notice shall be returned when work is completed or the HV Electrical Apparatus has been completely removed or demolished or the HV Electrical Apparatus is being readied for testing or commissioning. The Notice shall be returned in person by the On Site Supervisor to the Entity Representative. Page 7 of June 2012

8 8.5.1 Prior to returning the Not Notice the On Site Supervisor shall: Advise the work party that the Notice is to be returned, and that work is to cease and the HV Electrical Apparatus is to be treated as being Live. Ensure all work party members acknowledge that work is to cease and that the HV Electrical Apparatus is to be treated as Live by signing off the Notice and any associated supplementary page(s) for worker Sign On/Off. Ensure all mobile plant and equipment is clear. Ensure the current state of all Earths applied at the Work Area are recorded in Section 4 Earth Schedule of the Notice. Confirm that any barriers and signage erected by the On Site Supervisor have been removed. Record any abnormalities. Return the Notice by signing off The Entity Representative accepting the returned Not Electrically Connected Area Notice shall: Confirm the Notice and all associated supplementary documents are returned by the On Site Supervisor. Confirm all members of work party have signed off the Notice. Confirm all mobile plant and equipment is clear. Confirm any abnormalities and advise the Switching Coordinator if applicable. Confirm the current status of Earthing applied at the Work Area is recorded in Section 4 Earth Schedule of the Notice. Acknowledge the return of the Notice by signing in the appropriate field. Process the returned Notice as per Electricity Entity procedures. 9. References Queensland Electricity Entity Procedures for Safe Access to High Voltage Electrical Apparatus ENA NENS National Guidelines for Safe Access to Electrical and Mechanical Apparatus Electricity Entity Safety Rules and Procedures Electrical Safety Act 2002 Electrical Safety Regulation 2002 Page 8 of June 2012

9 10. Definitions for the purposes of this Guideline Approved Authorised Person Conductor Control Measures Disconnected Disconnection Point Earthed Earths Electrical Apparatus ( Part in QLD Electricity Safety Legislation) Electricity Entity Entity Representative Having appropriate organisation endorsement in writing for a specific function. A person with the technical knowledge and sufficient experience who has been Approved, or has the delegated authority to act on behalf of the organisation, to perform the duty concerned. A wire, cable or form of metal designed for carrying electric current. Policies, standards, procedures or actions to eliminate, avoid or minimise risks. Means that the parts are not connected to an electrical source. Disconnection may be achieved by de-energising, isolating, separating or breaking connections, or through all of these methods. A part that is Disconnected may still require discharging to remove all electric and other energy. An adequate break created by the removal or absence of Conductors and deemed no longer a source of inadvertent energisation. The break shall:- 1. not be able to be re-established by normal switching operations, and 2. maintain Exclusion Zone appropriate to the voltage or maintain electrical non-flashover distance appropriate to the voltage as defined by the Electricity Entity, and 3. be created in accordance with an Approved procedure to establish a Disconnection Point. Electrically connected to the general mass of earth by a Conductor to ensure and maintain the effective dissipation of electrical energy. Approved earthing devices applied for the earthing and shortcircuiting of Electrical Apparatus. Any electrical equipment, including Overhead Lines and underground Cables, the Conductors of which are Live or can be made Live. As prescribed in the Queensland Electricity Safety Act. An Authorised Person who has been Approved or has the delegated authority to act on behalf of the organisation to perform the duty concerned. Page 9 of June 2012

10 10. Definitions [continued] Exclusion Zone Live Mobile Plant (Operating Plant) Near Not Electrically Connected Not Electrically Connected Area Notice (Notice) Not Electrically Connected Area [NECA] On Site Supervisor Queensland Electricity Entity Procedures for Safe Access to High Voltage Electrical Apparatus. Outage Coordinator Switching Coordinator Work Area The Exclusion Zone, for a person for Electrical Apparatus, or for the Mobile Plant or a vehicle for Electrical Apparatus, means the distance from the Electrical Apparatus stated for the person, Mobile Plant or vehicle in the Electrical Safety Regulation 2002 Part 4 Section 61. Energised or subject to hazardous induced or capacitive voltages. Cranes, elevating work platforms, tip trucks or similar plant, any equipment fitted with a jib or boom and any device capable of raising or lowering a load. A situation where there is a reasonable possibility of a person, either directly or through any conducting medium, coming within the relevant Exclusion Zones. Electrical Apparatus Disconnected from all sources of supply by the removal or absence of Conductors, appropriate to the voltage and insulating medium and, not able to be energised by switching and identified in accordance with an Approved procedure. A document that forms part of a safe system of work and provides authorisation for work to be performed within a Not Electrically Connected Area. A defined area where documented authorisation has been issued to allow work to be performed on or Near Not Electrically Connected HV Electrical Apparatus. A person in control of the Work Area and responsible for electrical safety at the Work Area in situations where work is required on or Near Not Electrically Connected HV Electrical Apparatus. The Industry procedures for providing a safe system of work for all persons accessing the Entity s high voltage network and apparatus. An Authorised Person who negotiates and determines access / test requirements with an Applicant, and arranges for the production and issue of Switching Sheets and related Permits and Notices. An Authorised Person who co-ordinates switching, performs switching by remote control and approves the issue of Permits and Notices. The area where work may be carried out under a Not Electrically Connected Area Notice. Page 10 of June 2012

UNCONTROLLED COPY. Queensland Electricity Entity Standard for Safe Access to High Voltage Electrical Apparatus. August 2015

UNCONTROLLED COPY. Queensland Electricity Entity Standard for Safe Access to High Voltage Electrical Apparatus. August 2015 Queensland Electricity Entity Standard for Safe Access to High Voltage Electrical Apparatus August 2015 August 2015 Queensland Electricity Entity Standard for Safe Access to HV Electrical Apparatus I This