Draft Kenya Standard for Balloting Not to be Cited as Kenya Standard

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1 KENYA STANDARD KS :2010 ICS Electrical power transmission and distribution High-voltage operating regulations Part 5: Standard procedure and terminology for the issuing of operating instructions BALLOT DRAFT, MAY 2010 KEBS 2010 First Edition 2010

2 KS :2010 TECHNICAL COMMITTEE REPRESENTATION The following organizations were represented on the Technical Committee: Nairobi City Council, City Engineer s Department. Jomo Kenyatta University of Agriculture and Technology Kenya Polytechnic Kenya Power & Lighting Company Fluid & Power Systems Ltd Ministry of Public Works and Housing Ministry of Energy Kenafric Industries Ltd Power Technics Ltd Rural Electrification Authority The Energy Regulatory Commission Consumer Information Network Kenya Association of Manufacturers Institute of Engineers of Kenya Kenya Electricity Generating Company Ltd ABB LTD Switchgear & Controls Ltd Power Controls Ltd Communications Communication of Kenya Instrument Ltd Kenya Pipeline Company Ltd Telkom Kenya Ltd Meteorological Department Kenya Bureau of Standards Secretariat REVISION OF KENYA STANDARDS In order to keep abreast of progress in industry, Kenya standards shall be regularly reviewed. Suggestions for improvement to published standards, addressed to the Managing Director, Kenya Bureau of Standards, are welcome. Kenya Bureau of Standards, 2010 Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 12 of 2001 of the Laws of Kenya, copyright subsists in all Kenya Standards and except as provided under Section 26 of this Act, no Kenya Standard produced by Kenya Bureau of Standards may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from the Managing Director. ii KEBS 2010 All rights reserved

3 KENYA STANDARD KS :2010 ICS Electrical power transmission and distribution High-voltage operating regulations Part 5: Standard procedure and terminology for the issuing of operating instructions KENYA BUREAU OF STANDARDS (KEBS) Head Office: P.O. Box 54974, Nairobi-00200, Tel.: ( ) , , , Mobile: /8, /2; Fax: ( ) Web: KEBS Coast Region P.O. Box 99376, Mombasa Tel: ( ) , /40 Fax: ( ) KEBS Lake Region P.O. Box 2949, Kisumu Tel: ( ) 23549,22396 Fax: ( ) KEBS North Rift Region P.O. Box 2138, Nakuru Tel: ( ) , KEBS 2010 All rights reserved iii

4 KS :2010 F O R E W O R D This Kenya standard was prepared by the Switchgear and Distribution Equipment in accordance with the procedures of the Bureau and is in compliance with Annex 3 of the WTO/TB Agreement. This part of KS 1859 has been prepared to establish and promote uniform requirements for the issuing of operating instructions for application in the Electricity Distribution Industry. In the development of this standard, the South African Standard, NRS 040-5:2007, Rationalized User Specification High voltage regulations Part 5: Standard procedure and terminology for the issuing of operating instructions, was extensively consulted. Assistance derived from this source is hereby acknowledged. Normative and informative annexes A 'normative' annex is an integral part of a standard, whereas an 'informative' annex is only for information and guidance. Summary of development This Kenya Standard, having been prepared by the Switchgear and Distribution Equipment Technical Committee was first approved by the National Standards Council in June 2010 Amendments issued since publication Amd. No. Date Text affected iv KEBS 2010 All rights reserved

5 Contents KS : Scope Normative references Terms, definitions and abbreviated terms Terms and definitions Abbreviations Requirements Operating process Personal introduction Site and plant identification Scope of work verification System contingency planning Intercontrol arrangements Issue of operating instructions Confirmation of operating instructions Commencement of actual operating Reporting of completed operating Handing over and handing back of apparatus in substations Handing over and handing back of power lines or sections of power lines Control functions National/transmission control or interdistributor control Operating instruction forms Requirements before operating instructions can be issued Operating sequence Dressing control panels Manual VT selection Under-frequency load-shedding equipment Motorized isolators Transformer tap position control Specific operating sequence Returning an interconnected power system (IPS) line to service after maintenance Taking a transformer panel out of service for maintenance Safety test and earth Returning a transformer panel to service after maintenance Taking an interconnected power system transformer panel out of service Taking a bus coupler breaker or bus section breaker out of service Returning a bus coupler breaker or bus section breaker back to service Requirements for handing over and handing back apparatus Control functions after hand over KEBS 2010 All rights reserved v

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7 KENYA STANDARD KS :2010 Electrical power transmission and distribution High-voltage operating regulations Part 5: Standard procedure and terminology for the issuing of operating instructions 1 Scope This part of KS 1859 defines a procedure and terminology for control and field staff interaction when operating medium-voltage and high-voltage apparatus. NOTE This part of KS 1859 is an extension of legislation. Read this part of KS 1859 in conjunction with legislation. 2 Normative references The following referenced documents are indispensable for the application of this Kenya Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. KS , High-voltage operating regulations Part 3: Model regulations Recommended model regulations relating to power systems for operating, access control and supervision of systems that exceed 1000 V, for the transmission and distribution of electricity. 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions For the purposes of this part of KS 1859, the terms, definitions and abbreviations in KS and the following apply. authorized person person who has, in writing, been delegated defined authority and responsibility in terms of the relevant HV operating regulations bus coupler apparatus used for connecting two sets of busbar bus section breaker apparatus used for connecting two sections of the same busbar controller employee or official on duty at a control centre, who is responsible for the general operation of the power system or of a section thereof security linking contingency configuration of the network where isolation for maintenance could compromise network stability (i.e. redundancy or firm supply requirements) voltage regulator device used for automatic voltage control at a pre-set voltage 3.2 Abbreviations AVR HMI automatic voltage regulator human machine interface KEBS 2010 All rights reserved 1

8 KS :2010 HV IPS MV PTO PTS VT high voltage interconnected power system medium voltage permission to operate permission to sectionalize voltage transformer 4 Requirements 4.1 Operating process The following block diagram depicts the process and communication between control and field staff as discussed in this part of KS Personal introduction At every occasion that contact is established between a control officer and an authorized person in the field, the control officer and the authorized person will introduce one to the other by stating their full names If called for by either party, the identification will be confirmed with additional information like unique or identification numbers. 4.3 Site and plant identification Before operating instructions are being issued or received, the plant description and location will be stated in the following manner: a) the location of the plant will include the name of the line, feeder or substation as it appears on the equipment's nameplate and operating diagram nametag. The line name may be abbreviated; and b) the equipment to be operated will be identified by the standard symbol on the operating diagram and the equipment nameplate on the structure. 2 KEBS 2010 All rights reserved

9 4.4 Scope of work verification KS :2010 Before commencing with the work, the authorized person shall define the proposed scope of work to the control officer. This shall include the operating approach and placement of earths. The scope of work shall correspond with the plant outage documentation submitted to the control centre. 4.5 System contingency planning After the request for a specific outage, the control officer shall verify that a pre-arranged booking has been made. The booking shall specify all risks and hazards associated with the outage. The controller shall then assess the status of the substation and the power system to ascertain whether security linking is necessary. Security linking shall take precedence over any other operation. 4.6 Intercontrol arrangements If, for example, an interdistributor or IPS line is requested for isolation, the controller shall first confirm with the other control centre and then with National Control to verify the viability of the outage and obtain permission for the plant isolation. 4.7 Issue of operating instructions After the necessary discussions and request for permission have been completed, the actual operating instructions shall follow. In electronic operating, only the operating instructions agreed upon and included in the operating schedule will be given. The detailed instructions are discussed under "Requirements to make MV and HV apparatus safe to work on" in KS The authorized person will refer to the controller as "control" while the controller will address the authorized person by his first name and surname. The dialogue will be as follows: Controller: "<First name and surname of authorized person>, at <name of substation>, <nominal voltage, name of the panel >: open (or close) <name of the apparatus>", followed by all consecutive instructions, as necessary. 4.8 Confirmation of operating instructions After the authorized person has received his instructions, he will repeat the instructions to the controller and the controller can verify whether the operator has the instructions correctly. An instruction time is then given. In electronic operating, only the operating instructions agreed upon will be given. The dialogue will be as follows: Controller "<First name and surname of authorized person>, at <name of substation>, <nominal voltage, name of the panel>: I shall <open/close> <name of the apparatus>," followed by all consecutive instructions, 4.9 Commencement of actual operating The authorized person carries out the instructions in the sequence they were given to him or her, in accordance with the network operating regulations in KS A completion time is recorded on the operating instruction form Reporting of completed operating On completion of the operation, the authorized person shall report back to the controller that the operating has been performed. A reported time is issued Handing over and handing back of apparatus in substations Handing over After all isolation and earthing have been completed, the controller shall hand over the apparatus to the authorized person. Handover is an instruction and the operation shall be written out in full by the authorized person on an operating instruction form together with the time of handing over (handing back). KEBS 2010 All rights reserved 3

10 KS : Controller The dialogue shall be as follows: "<First name and surname of authorized person>, at <name of substation>, <nominal voltage, name of the apparatus> has been opened, isolated and earthed at all points of supply, You may commence with the specified work. On completion, remove all tools, equipment and workers and report back to me" Acceptance from the authorized person The dialogue shall be as follows: "<First name and surname of authorized person>, at <name of substation>, <nominal voltage and name of the apparatus> has been opened, isolated and earthed at all points of supply. I may commence with the specified work. On completion remove all tools, equipment and workers and report back to you", 4.12 Handing over and handing back of power lines or sections of power lines Handing over After all isolation and earthing have been completed, the controller shall hand over the apparatus to the authorized person. Handover is an instruction and shall be written out in full by the authorized person on an operating instruction form together with the time of hand over (hand back) Controller The dialogue shall be as follows: "<First name and surname of authorized person>, at <nominal voltage of and name of line>, from <abbreviated pole number> to <abbreviated pole number> the line has been opened and isolated from all points of supply, with a control earth at the point of isolation. You may test and apply working earths, commence with the specified work. On completion, remove all tools and equipment, workers and working earths from the line and hand back the line to me" As acceptance from the authorized person The dialogue shall be as follows: "<First name and surname of authorized person>, at <nominal voltage of and name of line>, from <abbreviated pole number> to <abbreviated pole number> the line has been opened and isolated from all points of supply, with a control earth at the point of isolation. I may test and apply working earths, commence with the specified work. On completion, I shall remove all tools and equipment, workers and working earths from the line and hand back the line to you" Control functions Control shall update the operating diagram according to the changed status of the network apparatus and lines, and record the authorized person's name against the relevant apparatus that has been handed over. Also record a reference number, if applicable National/transmission control or interdistributor control On completion of the necessary operating, an intercontrol handover will take place, thereafter apparatus will be handed out to the relevant authorized persons Operating instruction forms Operating instruction forms shall be in accordance with the examples given in KS Requirements before operating instructions can be issued When an outage is requested by field staff, the scope of work, operating sequence and number of earths required shall be discussed in detail before any instructions are issued. This is necessary to eliminate any misunderstanding or confusion. 4 KEBS 2010 All rights reserved

11 Operating instructions shall be issued and conversed in English Operating sequence Instructions shall be issued in the following sequence: a) switching; b) linking; c) safety testing; and d) earthing. KS : Where technology allows, control and equipment are not installed in separate rooms, switching shall be performed in the following order: a) supervisory facility; b) umbilical cord devices; and c) operating switches on the equipment panel Dressing control panels Auto-reclosing functions Auto-reclose schemes differ from one protection scheme to the next. The breaker's auto-reclose function shall be made inoperable as given in the site-specific procedure Telecontrol and supervisory functions Supervisory schemes differ from substation to substation and each substation requires different treatment. At some stations the supervisory shall be switched OFF before any operating is performed, whilst at others it shall be switched OFF depending on whether operating has been completed or whether operating is conducted remotely, manually or HMI. The requirements shall be stated in the local operating procedure Manual VT selection Where VT selection on busbars are not automated, the VT selection shall be performed manually when a busbar is taken out of service The racking in and out of truck type voltage transformers shall only be carried out under dead conditions. The particular requirements shall be stated in the local operating procedure Under-frequency load-shedding equipment Where a substation is equipped with an under-frequency facility, the selector switch shall be selected to the busbar that remains in service if the other busbar is taken out of service for maintenance purposes Motorized isolators All motorized isolators that are used as isolation points shall be made inoperable by disabling the supply to the motors Transformer tap position control When taking a transformer out of service and when returning it to service, the authorized person shall ensure that the substation auxiliaries and A VR controls are correctly selected as given in the sitespecific procedure. KEBS 2010 All rights reserved 5

12 KS : In the case of voltage regulators, the authorized person shall ensure that the tap changer is in the neutral or mid tap position and manual position before bypassing Specific operating sequence Taking a line breaker out of service for maintenance purposes (alive back) The procedure in to shall be followed when a line breaker is taken out of service for maintenance purposes Switch off supervisory (if relevant) Switch off auto-reclose (where applicable) Open breaker (specify voltage) Check breaker to be open (specify voltage) Open line isolator (specify voltage) Open busbar isolator (specify voltage) Safety test: the following shall be done during a safety test: a) earth busbar side of the breaker (specify voltage); b) earth the line side of the breaker (specify voltage); c) specify the number of earths; and d) obtain a handover from control Returning a line breaker to service after maintenance (alive back) The procedure in to shall be followed when a line breaker is returned to service after maintenance Hand back to control clear of workmen and equipment Remove earths at the busbar and line sides of the breaker (specify voltage), and specify the number of earths Check breaker to be open (specify voltage) Close busbar isolator (specify voltage) Close line isolator (specify voltage) Close breaker (specify voltage) Check line to be on load Switch to auto-reclose (where applicable) Switch to supervisory Verify with control centre that all alarms are clear Taking a line and breaker out of service for maintenance (dead back) The procedure in to shall be followed when a line and breaker are taken out of service for maintenance. NOTE Operating instructions are issued in separate steps because two or more authorized persons are involved. Control centres will co-ordinate operating in conjunction with each other Verify with control centre that all alarms are clear. 6 KEBS 2010 All rights reserved

13 Switch off supervisory (where applicable) Switch off auto-reclose (where applicable) Open breaker (specify voltage). (Supervisory shall be switched on for remote switching.) Check breaker to be open (specify voltage) Open line isolator (specify voltage) Open busbar isolator (specify voltage). NOTE the line. KS :2010 The busbar isolator can be left in the closed position if work is to be done on the line only. Earthing is then necessary only for Control centres to confirm the status of plant with one another Control centres to agree on numbers and positions of required earths Do a safety test: test apparatus for "dead" on all phases Earth busbar side of breaker if the busbar isolator is open (specify voltage) Earth line side of breaker if the busbar isolator is open (specify voltage) Earth on the line (specify voltage) Specify number of earths Control centres to hand over the line with one another as given in KS Control centres to hand over the line to various authorized persons to apply and remove working earth as given in KS Returning a line and breaker to service after maintenance (dead back) The procedure in to shall be followed when a line and breaker are returned to service after maintenance Authorized persons to hand back to control centre Control centres to hand back to each other and co-ordinate removal of earths Remove earths from a) busbar side of breaker, if applied (specify voltage), b) line side of breaker, if applied (specify voltage), c) the line (specify voltage), and specify number of earths removed Control centres to confirm removal of earths from one another and agree on linking Check breaker to be open (specify voltage) Close busbar isolator (specify voltage) Close line isolator (specify voltage) Control centres confirm status and agree on closing and switching of auto-reclose and supervisory Close breaker (specify voltage) Confirm loading Switch on auto-recloser (where applicable) KEBS 2010 All rights reserved 7

14 KS : Switch supervisory ON Verify with control centre that all alarms are clear Taking an interconnected power system (IPS) line out of service for maintenance Outage is sanctioned by National Control and operating instructions will be issued in separate steps as indicated in to This normally involves two control centres who will issue the isolation and earthing instructions in conjunction with each other Authorized persons to contact relevant control centres to commence with the requested outage Control centres to contact National Control and individually request permission to take line out. National Control assesses the situation, checks voltage and loading, and switches out the line at both ends (if required) through supervisory and applies a tag to the breakers. National Control hands out the line to each control centre to issue the necessary operating instructions and, on completion, hand back to National Control Control centres contact each other and co-ordinate the switching OFF of the supervisory and autoreclose and proceed with the isolation of line and busbar isolators. Control centres issue instructions to individual authorized persons Control centres notify each other that isolations are complete and co-ordinate application of earths Control centres issue earthing instructions Control centres hand out the line to each other Each control centre can now hand out the line or panel to the various authorized persons Returning an interconnected power system (IPS) line to service after maintenance The procedure in to shall be followed when an IPS line is returned to service after maintenance Authorized persons to hand line or panel back to control Control centres to hand line back to each other and co-ordinate removal of earths Control centres issue instructions to remove earths and return them to the authorized person Control centres contact National Control individually to hand back the line. clear of all earths National Control will sanction busbar selection and switch ON supervisory to control centres Control centre issues instructions to close busbar and line isolators and switching ON of supervisory to authorized persons. Receive confirmation that linking has been completed as instructed Control centres report back to National Control National Control closes breakers at both ends through the network supervisory system and requests auto-reclose to be switched ON. NOTE Authorized person shall remain on site to verify all remote switching Control centres to notify National Control Taking a transformer panel out of service for maintenance The procedure in to shall be followed when a transformer panel is taken out of service for maintenance. If the HV busbar links are connected to an IPS busbar, sanction from National Control shall be obtained before the transformer panel can be isolated Switch off supervisory Open auxiliary supply (where applicable). 8 KEBS 2010 All rights reserved

15 Open tertiary breaker (where applicable) (specify voltage) Open secondary breaker (specify voltage) Open primary breaker (specify voltage) Check breakers to be open (specify voltage) Test transformer to be dead Open primary busbar isolator (specify voltage) Open secondary busbar isolator (specify voltage) Open tertiary or auxiliary transformer isolator (where applicable) (specify voltage) Safety test and earth KS : In the case of work on transformers and breakers, and on the busbar side of the primary and secondary breakers, the primary, secondary and tertiary windings of the transformer shall be as specified in KS (specify voltages) In the case of work on transformers only, earth the primary, secondary and tertiary sides of the transformer (specify voltages) In the case of work on a breaker only, earth the busbar and transformer sides of the breaker (specify voltage) The control centre shall hand over the apparatus Fully isolate the panel and earth only the apparatus to be worked on. The handout shall be for that apparatus only Returning a transformer panel to service after maintenance The procedure in to shall be followed when a transformer panel is returned to service after maintenance The authorized person hands back the panel to the control centre office clear of workmen and equipment and fit for service If the primary busbar links are connected to an IPS busbar, sanction shall be obtained from National Control before the IPS line can be linked up Control centre issues instructions for the removal of earths Check breakers to be open (specify voltage) Close tertiary or auxiliary transformer isolator (where applicable) (specify voltage) Close primary busbar isolator (specify voltage) Close secondary busbar isolator (specify voltage) Close primary breaker (specify voltage) Close secondary breaker (specify voltage) Close tertiary breaker (where applicable) (specify voltage) Close auxiliary supply (where applicable) Switch supervisory ON. KEBS 2010 All rights reserved 9

16 KS : Taking an interconnected power system transformer panel out of service The operating sequence shall be the same as in the case of a demarcated transformer (taking out and returning to service) Taking a bus coupler breaker or bus section breaker out of service NOTE Some stations have automatic overcurrent and earth-fault protection schemes When changing over busbars from one to the other, start from one end of the busbar, proceed down the busbar closing all necessary isolators and thereafter proceed up the parallel busbar opening all necessary isolators When changing over busbars without a bus coupler, the dead busbar shall be proved healthy by means of a line or transformer breaker where possible The method of closing and opening each panel in turn is only used in special circumstances where the possibility of paralleling two zones through isolators exists. This method shall not be used where a bus coupler is not available On the bus coupler breaker, make sure that it is off overcurrent and earth-fault protection (where applicable). Then follow the steps in (a) to (h): a) link over all the relevant panels from one busbar to the other; b) switch OFF supervisory; c) open the bus section breaker (specify voltage); d) check breaker to be open (specify voltage); e) check bus coupler to be floating; f) switch OFF supervisory; g) open bus coupler breaker (specify voltage); and h) check breaker to be open (specify voltage) On the bus coupler, the following shall apply: a) open bus coupler, busbar 1 isolator (specify voltage); and b) open bus coupler, busbar 2 isolator (specify voltage) On the bus section, the following shall apply: open the relevant busbar isolators (specify voltage) Safety test On the bus coupler, the following shall apply: a) apply on earth busbar 1 on the bus coupler side of the breaker; b) apply on earth busbar 2 on the bus coupler side of the breaker; and c) apply earth on the bus section breaker, earth both sides of the bus section breaker On the busbar, the following shall apply: a) apply earth on the busbar; b) specify number of earths applied; and c) control to hand over apparatus to be worked on only. 10 KEBS 2010 All rights reserved

17 4.30 Returning a bus coupler breaker or bus section breaker back to service NOTE Some stations have automatic overcurrent and earth-fault protection schemes. KS : The procedure in to shall be followed when returning a bus coupler breaker or bus section breaker back to service Hand back apparatus to the control centre Remove all earths On the bus coupler, the following shall apply: a) check the breaker to be open (specify voltage); b) close bus coupler, busbar 1 isolator (specify voltage); c) close bus coupler, bus bar 2 isolator (specify voltage); d) switch on overcurrent and earth-fault protection (where applicable); e) close bus coupler breaker (specify voltage); f) switch off overcurrent and earth-fault protection; g) ensure busbar is alive from voltage indication; and h) switch ON supervisory On the bus section, the following shall apply: a) check the breaker to be open (specify voltage); b) close relevant busbar isolators of the bus section breaker (specify voltage); c) switch on overcurrent and earth-fault protection, where installed; d) close busbar section breaker (specify voltage); e) check breaker to be closed; f) switch off overcurrent and eath-fault protection, where installed; g) switch ON supervisory; and h) link over the required panels Taking a busbar or section of a busbar equipped with a bus coupler or section breaker out of service Switch off supervisory With the bus coupler or the bus section breaker closed and with overcurrent and earth-fault protection switched off, complete steps to Link over the required panels to clear the busbar or section Check that bus coupler or bus section breaker carry no load Open the bus coupler or bus section breakers Open isolators on either side of the breakers Test the relevant busbar or bus section to be dead Apply earths on the busbar or section of busbar according to KS Control centre hands over the busbar to be worked on only. KEBS 2010 All rights reserved 11

18 KS : Returning a bus bar or section of a busbar equipped with a bus coupler or bus section breaker to service Hand back busbar or section of busbar to control centre Remove all earths Specify number of earths Check breakers to be opened Close isolators on either side of the breaker Switch on overcurrent and earth-fault protection, where applicable Close breaker Switch off overcurrent and earth-fault protection Link over required panels Switch on supervisory Check that all alarms are clear Load transfer, isolating or energizing a section of a busbar without a bus coupler or bus section breaker Owing to different technologies and busbar configurations, all operating on unique plant shall be in accordance with local operating procedure Requirements for handing over and handing back apparatus After the apparatus has been earthed in accordance with KS , it shall be handed over to the authorized person. The authorized person shall be responsible for safety testing and for the application and removal of working earths when and where necessary on lines only. The authorized person shall write out the hand over or hand back on an operating instruction form together with the time handed over and time handed back on completion of work. All normal open points that are excluded should, where applicable, be recorded as part of the hand over After a line has been opened, isolated and earthed in accordance with KS between two contral centres, an "intercontral" hand over shall take place. In other words the contral centres shall hand over the line to each other for safety purposes irrespective of whether the contra I centre has work to be done. This is also applicable when working with customers that have recognized control centres Control functions after hand over The intercontrol hand over shall be recorded in both network management centres' operating logs The operating diagrams shall be dressed with the appropriate hand-over labels (i.e., intercontrol or the authorized person's name) The symbols used for dressing the operating diagram shall depend on local requirements. When lines have been handed out between control centres (i.e., intercontral hand over) the lines shall only be handed back when they are ready to be made live and not when work has been completed, i.e., all authorized persons have to hand back first. 12 KEBS 2010 All rights reserved