A REPORT TO THE BOARD OF COMMISSIONERS OF PUBLIC UTILITIES. Electrical. Mechanical. Civil. Protection & Control. Transmission & Distribution

Transcription

1 A REPORT TO THE BOARD OF COMMISSIONERS OF PUBLIC UTILITIES Electrical Q^sss^ - Mechanical Civil SIONATURI Zo \r or o', Protection & Control Transmission & Distribution Telecontrol System Planning ARC FLASH REMEDIATION PROGRAM April newfoundland labrador V, hydro a nakor energy company

2 Table of Contents INTRODUCTION PROJECT DESCRIPTION EXISTING SYSTEM. Age of Equipment or System. Major Work and/or Upgrades. Anticipated Useful life. Maintenance History.5 Outage Statistics.6 Industry Experience.7 Maintenance or Support Arrangements.8 Vendor Recommendations.9 Availability of Replacement Parts. Safety Performance. Environmental Performance. Operating Regime JUSTIFICATION. Net Present Value. Levelized Cost of Energy. Cost Benefit Analysis. Legislative or Regulatory Requirements.5 Historical Information.6 Forecast Customer Growth.7 Energy Efficiency Benefits.8 Losses during Construction.9 Status Quo. Alternatives 5 CONCLUSION 5. Budget Estimate 5. Project Schedule APPENDIX A Al Newfoundland and Labrador Hydro

3 INTRODUCTION An electrical arc is the result of air being stressed beyond its insulating ability, ionizing, and allowing current to flow. An extreme example of an electrical arc is lightning. A less extreme example is the spark from an automotive spark plug. When an arc occurs in an industrial electrical system, the resultant energy release can be catastrophic. This release of energy, called an arc flash, contains intense thermal energy that produces devastating sound and pressure waves, blinding light, intense ultraviolet rays and gaseous toxins. The main danger from an arc flash incident is the radiant heat energy which is capable of causing severe burns and the ignition of clothing. An arc flash explosion can heat the air to a maximum temperature of approximately 9,5 degrees Celsius which is roughly four times the surface temperature of the sun. Arc flashes are caused by accidental contact with energized equipment, electrical equipment malfunction and insulation failure, build up of conductive dust, corrosion, and/or improperly designed or utilized equipment. Arc flashes are rare and dangerous events that do not normally occur at voltages less than 6 Volts. Heat energy is usually expressed in calories per square centimeter (cal/cm ). An exposure of one cal/cm is approximately equal to being exposed to the hottest part of a cigarette lighter for one second. The amount of heat energy from an arc flash which could reach a worker is dependant upon the amount of available arc energy, the distance of the worker from the arc, and the time duration of the incident. The most serious arc burn injuries usually result when clothing is ignited during an arc flash incident. Workers who are exposed to potential arc flash situations are required to wear appropriate personal protective equipment (PPE) to ensure that they are properly protected. The appropriate clothing is determined by the Hazard Risk Category (HRC) which is defined in standards Newfoundland and Labrador Hydro Page

4 by the National Fire Protection Association (NFPA 7E) and the Canadian Standards Association (CSA Z6-8). For equipment with HRC =, workers are required to wear flame resistant shirt and pants or coveralls with a minimum arc rating of cal/cm. For equipment with HRC =, workers are required to wear flame resistant shirt and pants or coveralls with a minimum arc rating of 8 cal/cm. Hydro workers required to work on energized and exposed equipment with these arc flash levels are provided with coveralls which are suitable for category and situations. Category PPE is suitable for extended use. An example of category PPE is shown in Figure. Figure - Category PPE Newfoundland and Labrador Hydro Page

5 For equipment with HRC =, workers are required to wear an arc flash suit and hood with a minimum arc rating of 5 cal/cm. For equipment with HRC =, workers are required to wear an arc flash suit and hood with a minimum arc rating of cal/cm. These suits are available, but prolonged use is discouraged due to worker discomfort. Hydro workers required to work on energized and exposed equipment with arc flash levels greater than 5 cal/cm are provided with arc rated suits which are suitable for category and situations. An example of category PPE is shown in Figure. Figure - Category PPE Work on exposed and energized equipment with HRC > is not recommended. Labels are used to inform the workers of the details of the arc flash dangers for a particular piece of equipment. An example of a label is shown in Figure. Newfoundland and Labrador Hydro Page

6 Flash Hazard Category Flash Hazard Boundary X feet (X.X meters) Hazard Appropriate PPE Required USE CATEGORY PPE Calculated Arc Rating (caucm) X.X ARC FLASH PPE X Flame Resistant Clothing, Min Arc Rating of B cal/cm' Arc Rated Coveralls or Arc Rated Pants & Long-Sleeved Shirt Arc Rated Face Shield with Balaclava or Suit Hood X % Natural Fiber Undergarments PROTECTIVE EQUIPMENT X Hard Hat X Safety Glasses or Safety Goggles X Hearing Protection (Ear Canal Inserts) X Voltage Rated Coves with Leather Protectors X Leather Safety Shoes Equipment ID: XXXXXXXXXXXX Date: Figure - Warning Label During work on energized equipment, unprotected personnel must remain a safe distance from the equipment. This distance, defined as the Protection Boundary, is the distance at which a person would be exposed to no more than. cal/cm of thermal energy during an arc flash incident. In 8, Hydro initiated a study to calculate arc flash levels for various types of industrial electrical equipment for sites throughout the Hydro systems. This study determined the maximum thermal effects from an arcing fault so that the appropriate PPE could be identified for workers exposed to these potential arc flash situations. PPE is recognized as the last line of defense against arc flash injuries. Although PPE cannot prevent all injuries, it will lessen the impact of an arc flash. The arc flash study indicated that the maximum arc flash levels for a significant amount of Hydro's industrial electrical equipment are unacceptably high. Appendix A provides a list of sites showing the arc flash levels. By decreasing these arc flash levels, the risk of injury and/or property damage can be reduced. Newfoundland and Labrador Hydro Page

7 The requirement for determining arc flash risks was legislated in the United States in via the National Fire Protection Association (NFPA) 7E standard. In Canada, the 6 edition of the Canadian Electrical Code stated that an arc flash assessment must be performed, with reference to NFPA 7E and Institute of Electrical and Electronic Engineers (IEEE) Standard 58. The 6 edition of the Canadian Electrical Code, Section -6 - Shock and Flash Protection states that electrical equipment shall be field marked to warn persons of potential electric shock and arc flash hazards. This project will enable Hydro to comply with the Canadian Electrical code. Hydro will apply the appropriate technology and engineering controls to reduce or eliminate the arc flash levels of the existing equipment to a maximum level of HRC. Newfoundland and Labrador Hydro Page 5

8 PROJECT DESCRIPTION This project is required to perform the necessary upgrades to reduce the arc flash levels on Hydro's electrical equipment. Immediate remedial action is required in order to ensure the safety of workers exposed to arc flash situations. The upgrades will, whenever possible, reduce the arc flash levels of equipment to more acceptable levels of HRC or lower to comply with the Canadian Standards Association Z6-8 Standard. This program includes the remediation of the arc flash levels at the following sites: Hydraulic Sites: Bay d'espoir Powerhouse and, Cat Arm, Granite Canal, Roddickton, Upper Salmon, and the Victoria control structure. Gas Turbine Plants: Hardwoods, Stephenville and Happy Valley. Frequency Converter Stations: Corner Brook and Grand Falls. Although the rotating frequency converter at Grand Falls is decommissioned, the converter station building has electrical equipment in service for protection and control of the Grand Falls Terminal Station. Diesel Plants: Black Tickle, Cartwright, Charlottetown, Francois, Grey River, Happy Valley, Hopedale, L'Anse-au- Loup, Little Bay Islands, Makkovik, Mary's Harbour, McCallum, Natuashish, Port Hope Simpson, Postville, Rigolet, St. Anthony, St. Brendan's, St. Lewis, and William's Harbour. The remediation measures that will be implemented are dependent on individual site conditions. The remediation measures include: Newfoundland and Labrador Hydro Page 6

9 Changes to the existing relay settings to provide faster fault clearing times which will reduce the arc flash levels; Installation of special arc flash relays, which are devices designed to detect the presence of an arc flash and clear the fault instantaneously; Installation of multiple setting relays, which have dual protection settings (one for normal operation and one to be switched on when a worker is working on live or exposed equipment); Installation of current limiting fuses, which clear the fault instantaneously; and Installation of remote operators for circuit breakers, which allow the worker to operate the breaker from outside the arc flash boundary. The actual remediation measure or tactic to be implemented for each location has not yet been determined. Individual tactics or a combination of tactics may be employed at each location. Newfoundland and Labrador Hydro Page 7

10 EXISTING SYSTEM Equipment at Hydro's plants and facilities consists of conventional switchgear, motor control centers, disconnect switches, bus distribution splitters, distribution panels, and miscellaneous circuit breakers and isolating switches. The HRCs on Hydro's equipment range from to greater than and the Protection Boundary limits range from zero feet to as much as feet. Appendix A contains a table of all locations to be addressed in this project and lists the Arc Flash HRC and Protection Boundary for each piece of equipment at the various sites.. Age of Equipment or System The age of the equipment varies from about three years to years.. Major Work and/or Upgrades There have been no major work and/or upgrades on the equipment since its installation.. Anticipated Useful life The anticipated useful service life of electrical equipment is approximately years.. Maintenance History The maintenance history of the existing systems has no impact on this project..5 Outage Statistics There are no outage statistics relative to this project. Newfoundland and Labrador Hydro Page 8

11 .6 Industry Experience The North American utility industry in general and the utilities in particular use the NFPA 7E and CSA Z6-8 standards for electrical safety as it relates to arc flash hazards. The current industry practice is to take action to perform arc flash studies on all operating equipment. Equipment is labeled to show the arc flash category and arc flash boundary and actions are taken to reduce the hazard levels to create safe worker environments..7 Maintenance or Support Arrangements All maintenance work is performed by Hydro staff..8 Vendor Recommendations There are no vendor recommendations regarding this project..9 Availability of Replacement Parts Spare parts are generally available but delivery times may vary considerably among the different manufacturers.. Safety Performance Arc flash hazards are a concern to workers throughout the Hydro System. An arc flash incident on an electrical system with dangerous arc flash levels could result in injury or death to workers, and damage to equipment. The remedial efforts recommended in this project will help Hydro workers and external contractors avoid these risks. Newfoundland and Labrador Hydro Page 9

12 . Environmental Performance There are no specific environmental issues related to this project.. Operating Regime This project involves electrical equipment which is in continuous service throughout the Hydro System. Newfoundland and Labrador Hydro Page

13 JUSTIFICATION This project is justified on the requirement for Hydro to ensure the safety of workers who are exposed to arc flash hazards during the performance of their duties. In order to conform to the arc flash safety recommendations of the Canadian Standard Association, the Canadian Electrical Code, and the Standards Council of Canada and to ensure the safety of personnel throughout the system who are exposed to arc flash situations, Hydro must undertake an arc flash remediation program. An arc flash incident creates danger to workers and causes damage to electrical equipment. This project will minimize or eliminate the effects of an arc flash incident and reduce its impact on the production of energy should such an arc flash incident occur. The arc flash study completed in 8 identified deficiencies throughout Hydro's System where electrical equipment presented unacceptable arc flash levels for workers. Failure to upgrade these electrical systems creates liability issues for Hydro, especially since specific deficiencies have been identified.. Net Present Value A net present value calculation is not applicable as there is no viable alternative to performing remedial action to reduce arc flash levels in the Hydro systems.. Levelized Cost of Energy As this project does not relate to a specific generation source, levelized cost of energy is not applicable. Newfoundland and Labrador Hydro Page

14 . Cost Benefit Analysis A cost benefit analysis is not applicable as there are no quantifiable benefits.. Legislative or Regulatory Requirements In January, the Standards Council of Canada in conjunction with the Underwriter's Laboratories of Canada released the standard CAN/ULC-S8- "Standard on Electric Utility Workplace Electrical Safety for Generation, Transmission, and Distribution". This standard provides safety performance guidelines for electric utilities, workers, and employers involved in work on or near electric generation, transmission, and distribution systems. These guidelines include recommendations regarding arc flash protection. In particular, section 8.. of this standard states "Arc flash hazards should be eliminated or controlled through engineered solutions". The Canadian Standards Association announced the release of a standard CSA Z6-8 "Workplace Electrical Safety" on February, 9. This standard was designed to help prevent injuries and fatalities arising from the use of electricity on the job by specifying practical requirements for a safer workplace. This standard includes recommendations regarding arc flash similar to the recommendations provided by the NFPA 7E standard of the United States. The requirement for determining arc flash risks was legislated in the United States via the NFPA 7E standard in. Guidance for performing arc flash calculations comes from the Institute of Electrical and Electronic Engineers (IEEE) as presented in IEEE Standard 58- "IEEE Guide for Performing Hazard Calculations". In Canada, the 6 edition of the Canadian Electrical Code states that an arc flash assessment must be performed, with reference to NFPA 7E and IEEE 58. Newfoundland and Labrador Hydro Page

15 The 6 edition of the Canadian Electrical Code, Section -6 - Shock and Flash Protection states: "Electrical equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centres that are installed in other than dwelling units and are likely to require examination, adjustment, servicing, or maintenance while energized shall be field marked to warn persons of potential electric shock and arc flash hazards." The 6 edition of the Canadian Electrical Code Handbook, Appendix B, Notes on Rules, for Section -6 states the following: "NFPA 7E-, Electrical Safety in the Workplace, provides assistance in determining severity of potential exposure, planning safe practices, and selecting personal protective equipment to protect against shock and arc flash hazards." "ANSI Z55.-, Product Safety Signs and Labels, provides guidelines for the design of safety signs and labels for application to products." "IEEE 58-, Guide for Performing Arc-Flash Hazard Calculations, provides assistance in determining the arc flash hazard distance and incident energy that workers may be exposed to from electrical equipment.".5 Historical Information Hydro received approval under Board Order No. P.U. (7) to complete an arc flash study that included a review of nine hydroelectric sites, three gas turbine plants and diesel plants. The results of the studies provide the basis for upgrades identified in this project. The budget for this project was $, and the actual spent was $59,. Newfoundland and Labrador Hydro Page

16 .6 Forecast Customer Growth The forecasted customer load has no effect on this project..7 Energy Efficiency Benefits There are no issues related to energy efficiencies associated with this project..8 Losses during Construction There will be no losses during construction associated with this project..9 Status Quo The status quo is not an option. The provision of a safe environment for workers is imperative. If appropriate PPE is unavailable, or if the arc flash hazards are unacceptable, then the equipment is de-energized before maintenance is performed. This practice cannot be continued because it introduces unacceptable outage frequencies to customers. In particular, equipment which is rated above HRC should not be exposed while in an energized state. In order to work on this equipment, an outage is required. For many situations, especially for systems supplied by diesel generation, this will result in an outage to all of the customers in the community. Maintaining the status quo for this equipment would result in more frequent customer outages. To complicate matters, equipment is often required to be energized in order for troubleshooting work to proceed to determine the nature of the problem. This is not possible if the hazards are above acceptable levels and cannot be mitigated by PPE. Equipment which is rated at arc flash risk category or requires workers to use arc flash suits. Newfoundland and Labrador Hydro Page

17 These suits are large, bulky, and subject the wearer to heat stress. They are not recommended for prolonged use. The wearing of bulky arc flash suits for the performance of equipment maintenance diminishes the dexterity of the worker and presents operational and safety concern for workers.. Alternatives There are no viable alternatives to this project. To address the arc flash concerns, the upgrades outlined in this project must be completed. Newfoundland and Labrador Hydro Page 5

18 5 CONCLUSION In order to satisfy the arc flash specific safety recommendations of the CAN/ULC-58- standard and the Canadian Electrical Code, and to ensure the safety of personnel throughout the system who are exposed to arc flash situations, the work identified in this project must proceed. This project will minimize and/or eliminate the effects of an arc flash incident and reduce its impact on the safety of workers, and maintain the reliability of service to customers through reduced outages for maintenance or equipment failures. 5. Budget Estimate The budget estimate for this project is shown in Table. Table : Budget Estimate Project Cost:($ x,) 5 Total Material Supply Labour Consultant Contract Work Other Direct Costs O/H, AFUDC & Escln Contingency TOTAL Newfoundland and Labrador Hydro Page 6

19 5. Project Schedule The anticipated project schedule of major milestones for this proposal is shown in the Table. TABLE : Project Schedule Activity Milestone Project Start January Tender For Remote Breaker Operating Accessories February Develop Prioritized 5 Year Plan March Develop Detailed Recommendations For Year April Implement Year Remediation Efforts December Review Remainder of 5 Year Plan January Develop Detailed Recommendations For Year February Implement Year Remediation Efforts December Review Remainder of 5 Year Plan January Develop Detailed Recommendations For Year February Implement Year Remediation Efforts December Review Remainder of 5 Year Plan January Develop Detailed Recommendations For Year February Implement Year Remediation Efforts December Review Remainder of 5 Year Plan January 5 Develop Detailed Recommendations For Year 5 February 5 Implement Year 5 Remediation Efforts December 5 Project Completion December 5 Newfoundland and Labrador Hydro Page 7

20 Appendix A APPENDIX A Levels Newfoundland and Labrador Hydro Al

21 Appendix A TABLE DIESEL PLANT ARC FLASH LEVELS Location Hazard Risk Category Boundary (feet) Black Tickle Diesel Plant HRC AFB 6 V Generator Power Circuit Breakers 6 V Main Splitter & Station Service Main Disconnect Switch 6 V Station Service Splitter, Disconnects & Loads Cartwright Diesel Plant HRC AFB 6 V Power Circuit Breaker for Each Generator 6 V Station Service Splitter & Disconnects 6 V Motor Starters for Generator Cooling Charlottetown Diesel Plant HRC AFB 6 V Generator Breakers 6 V Main Splitter & Station Service Main Breaker 6 V Station Service Splitter & Disconnects 6V Station Service Feeders Francois Diesel Plant HRC AFB 6 V Main Switchgear & Breakers for Each Generator 6 V Disconnect for Station Service 6 V Station Service Splitter & Disconnect Grey River Diesel Plant HRC AFB 6 V Switchgear & Breakers 6 V Station Service Main Breaker 6 V Station Service Main Disconnect, Splitter & Feeder Disconnects Happy Valley Diesel Plant HRC AFB 6 V Switchgear & Breakers 6 V Breaker for Station Service 6 V Station Service & Disconnects 6 V Splitter & Disconnects for Generator Cooling 6 V Distribution Panel for Building Heating 6 V Main Disconnect for Maintenance Shop 6 V Splitter, Disconnects & Distribution Panels > > > > > Newfoundland and Labrador Hydro A

22 Appendix A Location Hazard Risk Category Boundary (feet) Hawke's Bay Diesel Plant HRC AFB 6 V Switchgear 6 V Main Disconnect 6 V MCC 6 V Feeder Disconnects for Cooling Fans Hopedale Diesel Plant HRC AFB 6 V Switchgear & Generator Breakers 6 V Station Service Main Disconnect 6 V Station Service Splitter, Disconnect, Motor Starter & Loads L'anse-au-Loup Diesel Plant HRC AFB 6 V Switchgear & Circuit Breakers 8 V Station Service Main Disconnect 8 V Station Service Transfer Switch, Splitter & Disconnects 8 V Emergency Supply Disconnect Little Bay Islands Diesel Plant HRC AFB 6 V Main Switchgear & Generator Breakers 6 V MCC 6 V Station Service Feeders Makkovik Diesel Plant HRC AFB 6 V Switchgear & Generator Breakers 6 V Main Splitter & Station Service Main Disconnect 6 V Station Service Splitter, Disconnect & Loads Mary's Harbour Diesel Plant HRC AFB 6 V Main Switchgear & Breaker 6 Station Service Disconnect 6 V Station Service Splitter & Feeders McCallum Diesel Plant HRC AFB 6 V Main Switchgear & Generator Breakers 6 Station Service Main Disconnect 6 V Station Service Splitter & Feeders Nain Diesel Plant HRC AFB 6 V Switchgear, Breakers & Disconnect Switch 5 > > > > Newfoundland and Labrador Hydro A

23 Appendix A Location Line Side 8 V Main Breaker for MCC 8 V MCC & Local Disconnects for Generator Cooling & Building Heating Hazard Risk Category Boundary (feet) Natuashish Diesel Plant HRC AFB 6 V Switchgear, Breakers & Disconnect Switch Line Side 8 V Main Breaker for MCC 8 V MCC & Local Disconnects for Generator Cooling & Building Heating Norman Bay Diesel Plant HRC AFB 6 V Generator Breakers 6 V Station Service Disconnect 6 V Station Service Splitter, Disconnects & Connected Loads Paradise River Diesel Plant HRC AFB 6 V Main Splitter, Generator Breakers & Station Service Main Disconnect 6 V Distribution Panel Port Hope Simpson Diesel Plant HRC AFB 6 V Main Breaker & Generator Breakers 6 V Station Service Main Disconnect 6 V Station Service Splitter, Feeders & Loads Postville Diesel Plant HRC AFB 6 V Switchgear & Breakers 6 V Main Splitter, Station Service Splitter & Disconnects 6 V Connected Loads Ramea Diesel Plant HRC AFB 6 V Main Unit Bus 8 V Station Service Splitter 8 V S/S Disconnects, Motor Starters and Feeders Rigolet Diesel Plant HRC AFB 6 V Switchgear & Power Circuit Breakers 6 V Station Service Main Disconnect 6 V Station Service Splitter & Disconnects > Newfoundland and Labrador Hydro A

24 Appendix A Location Hazard Risk Category Boundary (feet) St. Anthony Diesel Plant HRC AFB 6 V Main Switchgear & Breaker 6 V Station Service Main Disconnect 8 V Station Service Main Breaker 8 V Station Service Splitters, Disconnect & Connected Loads St. Brendan's Diesel Plant HRC AFB 6 V Switchgear & Breakers 6 V Station Service Main Disconnect 6 V Station Service Splitter & Disconnects St. Lewis Diesel Plant HRC AFB 6 V Switchgear & Breakers 6 V Station Service Main Disconnect 6 V Station Service Splitter, Disconnect & Connected Loads William's Harbour Diesel Plant HRC AFB 6 V Power Circuit Breaker & Switchgear 6 V Station Service Splitter & Disconnects 6 V Breaker Panel 6 V Heater & Motor Starters Newfoundland and Labrador Hydro AS

25 Appendix A TABLE FREQUENCY CONVERTER ARC FLASH LEVELS Location Hazard Risk Category Boundary (feet) Corner Brook Frequency Converter HRC AFB 6 V Main Breaker for Station Service 6 V Distribution Panel 6 V Feeder Disconnects & Motor Starters 7 Grand Falls Frequency Converter HRC AFB 6 V Main Breaker for Station Service 6 V Distribution Panel 6 V Feeder Disconnects & Motor Starters 7 TABLE GAS TURBINE ARC FLASH LEVELS Location Hazard Risk Category Boundary (feet) Happy Valley Gas Turbine HRC AFB.8 kv Switchgear & Breaker.8 kv Isolation Switch for SST Line Side of 6 V Breaker for SST & SST 6 V Automatic Transfer Switch, MCC, Distribution Panel & 5 Disconnects Hardwoods Gas Turbine HRC AFB.8 kv Switchgear & Breakers 6 V APT Secondary Main Breaker 6 V GT Secondary Fused Disconnect 6 V GT Secondary Main Breaker 6 V MCC & Comb. Starters for Pump GGA & GGB 6 V Terminal Station Panel A Compressor Transfer Switch & Starter Back-up Generator Panel > > Newfoundland and Labrador Hydro A6

26 Appendix A Location Hazard Risk Category Boundary (feet) Line Side of Main Breaker for Back-up Generator Feeder Disconnects Stephenville Gas Turbine HRC AFB.8 kv Generator Breaker 6 V SST Secondary Main Breaker 6 V GT Secondary Fused Disconnect 6 V MCC 6 V Transfer Switch Disconnect Switches for Supply. Pumps A & B 6 V Disconnects & Starters > TABLE HYDRO PLANT ARC FLASH LEVELS Location Hazard Risk Category Boundary (feet) Bay D'Espoir Powerhouse # HRC AFB.8 kv Isolation Switches 6 V PDC SSB & SSB Line Side of 6V Breaker for SST & SST Line Side of 6V Breaker for SSL 6 V PDP 6, 6, 6, 6, 65, 66,67, 69, & 7 6 V Disconnects, Motor Starter & Loads > 6 Bay D'Espoir Powerhouse # HRC AFB.8 kv Isolation Switches 6 V PDC SSB & Unit 7 SSL Line Side of 6V Breaker for SST & Unit 7 SS 6 V PDP 7, 7, 7 & 75 6 V Disconnects, Motor Starter & Loads Bay D'Espoir Intake Structures HRC AFB Newfoundland and Labrador Hydro A7

27 Appendix A Location Hazard Risk Category Boundary (feet) 6 V Main Disconnect Switch 6 V Disconnects & Connected Loads Bay D'Espoir Surge Tanks HRC AFB 6 V Main Disconnect Switch 6 V Disconnects & Connected Loads Bay D'Espoir Potable Water Supply HRC AFB 6 V Main Disconnect Switch 6 V Disconnects & Connected Loads Bay D'Espoir Garage / Machine Shop HRC AFB 6 V Main Disconnect Switch 6 V Splitter For Garage, Welding & Machine 6 V Disconnects & Connected Loads 5 Bay D'Espoir Carpenters Shop HRC AFB 6 V Main Breaker 6 V Disconnects & Connected Loads Cat Arm Hydro Plant HRC AFB.8 kv Isolation Switches 6 V Power Distribution Center SSB &SSB Line Side of 6V Breakers for SSB, SSB & SSD 6 V Power Distribution Panels ESB, ESB, NESB, NESB & NESB 6 V Disconnects, Motor Starters, Welding Receptacles & Heaters 6 V Intake Structure Distribution Panel SB 6 V Intake Structure Feeders 8 5 Ebbegunbaeg Control Structure HRC AFB 6 V Main Disconnect Switch 6 V Diesel Control Structure Panel 6 V Diesel Control Panel 6 V Starters, Controllers & Disconnects 6 V Welding Receptacle 5 Granite Canal Hydro Plant HRC AFB.8 kv Switchgear, Breakers & Disconnects 6 Newfoundland and Labrador Hydro A8

28 Appendix A Location Hazard Risk Category Boundary (feet) 6 V Switchgear SSB &SSB Line Side of Main Breakers for SSB & SSB Line Side of Breakers for Diesel Generator SSD 6 V Dist Panels NESB, NESB, ESB & NESP5 6 V Fire Pump Controller # & # 6 V Distribution Panel ESP 6 V Feeder Disconnects & Motor Starters 9 Hinds Lake Hydro Plant HRC AFB.8 kv Generator Breaker & Isolation Switch 6 V Power Distribution Centre (PDC) SSB Line Side of 6 V Breaker for SSB 6 V PDC SSD Line Side of 6 V Breaker for SSD 6 V Distribution Panels (DPs) ESB, ESB, NESB, NESB & NESP 6 V DP Intake & Spillway 6 V Disconnect Switches, Motor Starters,Welding Plugs & Other Remote Equipment 6 V Disconnects Fed From ESB & ESB Paradise River Hydro Plant HRC AFB 6 V Main Switchgear 6 V Transfer Switch Distribution Panel A Emergency Distribution Panel EA 6 V Disconnect Switches, Motor Starters, Welding Plugs & Other Remote Equipment Roddickton Hydro Plant HRC AFB 6 V Switchgear & Power Circuit Breaker 6 Salmon River Spillway HRC AFB 6 V Main Splitter in Gate House # 6 V Main Disconnect in Gate House # 6 V Feeder Disconnect for all the Gates Newfoundland and Labrador Hydro A9

29 Appendix A Location Hazard Risk Category Boundary (feet) Snook's Arm Hydro Plant HRC AFB 69 V Switchgear 9 Upper Salmon Hydro Plant HRC AFB.8 kv Switchgear, Breaker & Isolation Switch 6 V Switchgear & Breakers 6 V Power Distribution Panels -D, -F & -G 6 V Fire Pump Controller 6 V Disconnect Switches & Connected Loads North Salmon 6 V Main Disconnect Switch North Salmon 6 V Power Distribution Panels North Salmon 6 V Disconnect Switches & Connected Loads Intake Structure 6 V Main Disconnect Intake Structure 6 V Feeder Disconnect & Connected Loads Venom's Bight Hydro Plant HRC AFB 69 V Switchgear 8 Victoria Control Structure HRC AFB 6 V Main Distribution Panel Diesel Generator Breaker Enclosures Distribution Panel "A" Starters for Limitorque Motors 6 West Salmon Spillway HRC AFB 6 V Main Fused Disconnect 6 V Transfer Switch & Main Splitter 6 V Distribution Panel DPI 6 V Distribution Panels DP & DP 6 V Disconnect for Generator Cooling, Heating & Monorail 6 V Generator Main Breaker Newfoundland and Labrador Hydro A