SPECIFICATION NO.1197S Addendum No.5 Attachment H. TVRWRF Electrical Coordination Studies. Page 1 of 2 Specification No. 1197S Addendum No.

Transcription

1 SPECIFICATION NO.1197S Addendum No.5 Attachment H TVRWRF Electrical Coordination Studies Page 1 of 2 Specification No. 1197S Addendum No. 5

2

3 TVRWRF Electrical Coordination Studies: ATTACHMENT H TABLE OF CONTENTS TVRWRF Power System Analysis Report (dated 9/30/2015 by PES ) Page 2 of 2 Specification No. 1197S Addendum No. 5

4 September 30,2015 POWER SYSTEM ANALYSIS REPORT Client: Eastern Municipal Water District 2270 Trumble Road Perris, CA Sntdy Perþrmed for Location: Temecula Valley R\ryRF Photovoltaic System Installation PES Reference: s This leport was prepared by: The results of this study relate only to those items covered in this report and not to the condition or acceptance of any other related equipment. This report shall not be reproduced, except in full, without the written approval of PES Saturn Street, Brea,CA,9282l Telephone (714) Facsimile (714)

5 PES No.4863B-15 EMWD/Aro Flash Dianne Kilwein, P,E. Civil Engineer Eastern Municipal Water District 2270 Trumble Road Perris, CA92572 Subject: Eastern Municipal Water District Photovoltaic System Power System Analysis Dear Ms. Kilwein, Power Engineering Sewices, Inc. (PES) performed a Power System Analysis, inclucling Short Circuit and Protective Device Coordination Studies, and an Arc Flash Hazard Assessment for the Eastern Municipal Water District Photovoltaic System at as requested and in accordance with the PES proposal. This analysis includecl all of the electrical equipment operating at 480V and V, including new switchboards, new step-up/step-down transformers, and new panelboards. Data for the analysis were collected from construction drawings and manufacturer's submittals and shop drawings. The results of the Power System Analysis relate only to those items covered in this report. This report shall not be reproducecl, except in full, without the written approval of PES. If you have any questions concerning this report, please clo not hesitate to contact our office. Cordially, 2703 Saturn Street, Brea,CA,9282l Telephone (714) Facsirnile (714) 'ù/ww.pespower.com

6 September 30,2015 PES No Report Certification Page No Eol2 185 I hereby certify supervision and California. that that this engineering document was prepared by I am a duly licensed Professional Engineer me or under rny direct personal under the laws of the State of 3a %E Douglas E. Effenberger, P.E. License Number: E-0 I 2485 License Expiration: September 30, Saturn Street, Brea, CA Telephone (714) Facsimile (714)

7 TABLE OF CONTENTS Section Contents Page EXECUTIVE SUMMARY GENERAL Purpose Scope Analytical Software Study Notes and Assumptions SHORT CIRCUIT STUDY General Short Circuit Model Simplifications Short Circuit Study Results PROTECTIVE DEVICE COORDINATION STUDY General Calibration and Testing of Protective Devices Recommended Protective Device Settings ARC FLASH HAZARD STUDY General SKM Arc Flash Module Calculation Assumptions SKM Arc Flash Module Study Options Arc Flash Hazard Study Results PROJECT RECOMMENDATIONS APPENDIX A APPENDIX B APPENDIX C APPENDIX D APPENDIX E APPENDIX F APPENDIX G SHORT CIRCUIT INPUT DATA & CALCULATION RESULTS, 30 pages SELECTED TIME-CURRENT CURVES, 13 pages ARC FLASH CALCULATIONS, 7 pages UTILITY SHORT CIRCUIT DUTY, 2 pages GLOSSARY, 3 pages INVERTER TECHNICAL DATA, WITH SHORT CIRCUIT CONTRIBUTION, 1 page SCHEMATIC DIAGRAMS DEVELOPED FOR STUDIES, 4 pages Table of Contents, Page 1 of 1

8 EXECUTIVE SUMMARY Background The Power System Analysis included Short Circuit, Protective Device Coordination, and Arc Flash Hazard studies of electrical equipment at Eastern Municipal Water District. This study includes new equipment to be installed as part of a facility photovoltaic installation. The Short Circuit study investigated the ability of equipment to interrupt and withstand a short circuit occurrence. The Protective Device Coordination study determined the selective operation of protective devices to assure the device closest to a fault or overload operates in order to minimize the number of apparatus that are affected. The Arc Flash Hazard assessment calculated the amount of energy that would be released in the event of an arcing short circuit at each equipment location. Personal Protective Equipment (PPE) was then specified based on the available arc energy and other factors such as the operating voltage of the equipment. PPE must be utilized by personnel performing work on electrical equipment, unless the equipment has been de-energized and confirmed to be safe by lock-out and tag-out testing procedures. Data Gathering Data for the analysis were collected from construction drawings, manufacturer s submittals and shop drawings. The data gathered included electrical plan and single-line drawings, equipment details, and protective device ratings. Available fault current at the utility services was provided by Southern California Edison. Short Circuit Study A short circuit study was performed in order to determine the maximum available short circuit current at each equipment component included in this study. The calculated values of short circuit current were compared to the equipment short circuit ratings. Equipment must have a withstand or interrupting rating that exceeds the calculated value of short circuit current in order to safely withstand the occurrence of a short circuit. If a device is subjected to short circuit currents greater in magnitude than its ratings, equipment damage and injury to personnel are likely. The short circuit study showed that all system components studied were suitably rated for the available short circuit current. All devices in the system had a withstand or interrupting rating that exceeded the worst-case calculated short circuit current, in compliance with California Electrical Code Page 1 of 19

9 Protective Device Coordination Study The goal of the Protective Device Coordination study is to provide proper coordination and time separation between the operation of protective devices. Proper coordination among protective devices will minimize the amount of equipment that would be affected by a short circuit or overload event. In the event of a short circuit or overload, the protective device closest to the short circuit should operate when devices are properly coordinated. In the event that the closest device does not clear the short circuit the next upstream device should then operate. Recommended protective device settings for adjustable devices are provided in Section 3 of this report. The recommended protective device settings will provide coordination between upstream and downstream circuit breakers, as well as minimize Arc Flash incident energy values. Arc Flash Hazard Study The Arc Flash Hazard study determines the incident energy and flash hazard boundary resulting from an arcing short circuit. Warning labels for the equipment were produced as part of this study that identify Arc Flash hazards, including approach boundaries, shock hazard boundaries, and required PPE to be worn by personnel working on the equipment while it is energized. The following equipment had calculated incident energies above 8.0 cal/cm 2. Incident energies above 8.0 cal/cm 2 require personnel to wear arc flash hazard suits with an arc rating that matches or exceeds the incident energy calculated and printed on the arc flash warning label. Reduction of the incident energy values at the following equipment is not readily feasible due to either relatively low available fault current, or lack of adjustable settings on protective devices such as thermal-magnetic circuit breakers and fuses. However, additional barriers and guards can be installed on equipment to provide enhanced protection against accidental contact with energized equipment parts. Refer to Section 4.4 for more details. Equipment Incident Energy Value ACDS-1 23 PNL-1 34 PNL-2 21 TR-1 Secondary 35 TR-2 Primary (480V) 15 For all equipment, personnel must use PPE with an arc rating that meets or exceeds the incident energy printed on the arc flash warning label. Note that the arc flash incident energies are valid only when the recommended circuit breaker settings in Section 3.3 are applied. Page 2 of 19

10 Validity Statement This Power System Study and Arc Flash Hazard assessment is accurate as of the date of this report for the equipment installed as shown on the attached one-line drawings. Changes to the electrical system circuits, including system impedance, short-circuit duty, voltage, or fault clearing times, will invalidate this study and require re-evaluation, calculation, and installation of new warning labels. This study should be updated on a regular basis and at intervals no greater than allowed by applicable Codes and standards. Page 3 of 19

11 1.0 GENERAL 1.1 Purpose 1.2 Scope The purpose of this power system study was to identify and establish the arc flash hazards at the Eastern Municipal Water District new photovoltaic system electrical equipment. Arc flash hazards were identified and calculated. Personal protective equipment (PPE) requirements applying to each component within the scope of work for this study were determined. Warning labels were provided that comply with 2014 CEC and 2015 NFPA 70E requirements in effect as of this report date for arc flash hazards. The scope of the Arc Flash study is limited to: new electrical equipment for the new photovoltaic system. 480V switchboards, 12kV-480V transformers, 480V panelboards, and 480V inverters. Determination of short circuit fault currents available at the electrical components within the scope of the study. Comparison of the calculated short circuit current values to the short circuit current ratings of the equipment within the scope of the study. Providing recommended settings for protective devices. Determination of Arc Flash incident energy available at the electrical components within the scope of the study. Listing required arc rating of personal protective equipment (PPE) in accordance with NFPA 70E to be worn by personnel while working on energized equipment. The scope of the Arc Flash study does not include: Building and site electrical equipment and systems not listed above. Evaluation of the competency of design of the electrical distribution system. Evaluation of the adequacy of design of the electrical distribution system. Evaluation of compliance of electrical distribution installation to California Code of Regulations Title 24, Part 3, California Electrical Code (CEC), NFPA 70, National Electric Code (NEC), or local codes. Evaluation of workmanship of electrical distribution system installation. Evaluation of the material condition of the electrical distribution system components. 1.3 Analytical Software The software package used for modeling the system and performing all of the studies was SKM Power Tools, version Page 4 of 19

12 1.4 Study Notes and Assumptions SKM did not have a library file in the program for the XHHW conductors specified for this project. Copper conductors with THHN/THWN insulation were used for circuits 600V and below unless otherwise noted. The variance concerns the type of insulation used over the conductor; not the conductor itself, and will not significantly affect the results of the studies presented in this report. The 1600A model LCL fuses used in the 1600A disconnect are shown in the study reports as Federal Pacific. Federal Pacific s fuse line was acquired by Edison Fuse Products, which was later acquired by Cooper/Eaton. Eaton is providing the electrical equipment for this project, including the LCL fuses. The time-current characteristics have not changed for this particular model of fuse. All overcurrent protective devices will perform as designed by the manufacturer, and operate according to the manufacturer s published time-current curves. Page 5 of 19

13 2.0 SHORT CIRCUIT STUDY 2.1 General The purpose of the Short Circuit Study is to determine the levels of bolted fault current that can flow in an electrical system when a fault occurs at a specific location in that system. Arc flash calculations use this level of bolted fault current for determining arcing fault current and incident energy levels. Circuit breakers and fuses must have an interrupting rating which exceeds the maximum bolted fault current available at its location. Equipment such as switchboards and panelboards must have a withstand rating of equal or greater value than the calculated bolted fault current. The Short Circuit Study models the electrical system impedance by determining an equivalent impedance for all system components and then calculates bolted fault current at various busses. The short-circuit duty is a function of the utility short circuit capacity, on-site source contributions such as motors and generators, and system impedance from cables and transformers. Bus locations may be identified by referring to the one-line diagram in Appendix G of this report. Two short circuit study cases were calculated: The first case uses the short circuit current calculated by Solar City and the design engineer of record, the second case uses the short circuit current calculated by Southern California Edison (SCE) in The value of current calculated by Solar City was 64,174A at 480V. The values calculated by SCE were 25,500A 3- phase, 27,300A single phase to ground, at 480V. As long as the main service switchboard or service equipment is not upgraded, the short circuit values calculated by SCE should still be valid. The much larger value of short circuit current provided by Solar City is most likely based on an infinite bus value of the largest utility transformer sized for the full 3,000A rating of the existing 480V switchboard. Short circuit values using the infinite bus method yield conservatively high values of current, and will be the worst case values calculated. The values provided by SCE are based on the rating of the utility service transformer presently installed, which is frequently rated less than the full-load rating of the customer switchboard. Refer to Appendix D for values calculated by SCE. Utilities typically install a smaller-rated transformer due to the fact that most customers have a peak electrical demand much less than the full-load rating of the customer s main service. Even though the short circuit value provided by Solar City may be higher than what can be provided with presently installed service equipment, the value is useful for specifying interrupting ratings of equipment. If the utility service is upgraded in the future, the equipment installed for the photovoltaic system will still have an adequate interrupting rating, and will not require component replacement as long as the EMWD switchboard is not upgraded. PES ran four study cases which considered the short circuit duties calculated by SCE and Solar city, as well as short circuit current contribution from the photovoltaic arrays: Page 6 of 19

14 1. Short circuit values calculated by Solar City, no photovoltaic contribution. 2. Short circuit values calculated by SCE, no photovoltaic contribution. 3. Short circuit values calculated by Solar City, photovoltaic contribution per the inverter datasheet. Per the inverter datasheet, the maximum short circuit contribution from the inverter is 69.6A three-phase, 52.9A single line to ground. The inverter will only conduct short circuit current for one cycle. After a maximum of 20ms, the inverter will stop conducting current. Refer to Appendix F for the short circuit contribution from the inverter. 4. Short circuit values calculated by Solar City, photovoltaic contribution per the inverter datasheet. Per the inverter datasheet, the maximum short circuit contribution from the inverter is 69.6A three-phase, 52.9A single line to ground. The inverter will only conduct short circuit current for one cycle. After a maximum of 20ms, the inverter will stop conducting current. Refer to Appendix F for the short circuit contribution from the inverter. 2.2 Short Circuit Model Simplifications A number of conventional simplifying assumptions were used to establish a system model that reasonably represents the magnitude of fault current the system is capable of producing. The assumptions generally produce a conservative or worst case set of values. The major assumptions utilized in this study include the following: Fault current calculations include initial symmetrical fault with ½ cycle asymmetrical contribution. Available fault current values at the utility services were obtained from Southern California Edison and Solar City construction drawings, and are assumed to be valid for the system model and conditions of this study. Protective device impedances and equipment bus impedances were neglected. Pre-fault voltages were set at 1.0 per unit. Impedance elements remain constant during a system fault. Reported fault levels represent three-phase and single-line-to-ground bolted faults. 2.3 Short Circuit Study Results The results of the short circuit study identified that all components included in this study were suitably rated for the available fault current under both study cases. Using both the short circuit values calculated by Solar City, and the values calculated by SCE, each device had a withstand or interrupting rating that met or exceeded the calculated available fault current, in accordance with California Electrical Code For complete results of the Short Circuit study, including source and impedance ratings input into the model and calculation results, refer to Appendix A of this report. Bus locations may be identified by referring to the one-line diagram in Appendix G of this report. Page 7 of 19

15 3.0 PROTECTIVE DEVICE COORDINATION STUDY 3.1 General The primary function of electrical power system fault protective devices is to detect a fault current and to isolate the fault by activating the proper interrupting device. A fault should be removed as quickly as possible by the closest upstream protective device to minimize fault damage, maintain maximum service continuity, and protect property and personnel. 3.2 Calibration and Testing of Protective Devices Current transformer ratios and sensor devices must be verified before making any changes to protective device settings. After verification, protective devices can be set to provide the characteristic curves shown in the appropriate TCC. In general, the specified settings will provide operation of the devices as shown. However, equipment tolerances and possible defects in device operation may result in deviations from the desired operating times. Therefore the device settings should be calibrated by field tests to help assure the desired response. Coordination depends on operation of the protective devices as shown, though the devices may be normally inactive for long periods. To assure continuing device coordination, it is essential that all protective devices are maintained, tested, and calibrated at regular intervals, as recommended by the manufacturer. 3.3 Recommended Protective Device Settings Recommended settings are provided below for all adjustable circuit breakers. Non-adjustable circuit breakers and fuses are not listed below. The recommended settings will minimize arc flash incident energy by minimizing breaker trip time, while maintaining device coordination between main and feeder protective devices. These recommended protective device settings should be programmed during equipment testing and commissioning. Relay/Breaker MSB2 Main Circuit Breaker (In Existing Main Switchboard) Description Square D SE, 3000A Micrologic LIG Trip Unit Settings LTPU LTD INST GFPU GFD Existing A, I 2 t OFF 0.5 Recommended A, I 2 t OFF 0.5 Relay/Breaker EPPDP2 Circuit Breaker (In Existing Main Switchboard) Description Square D NE, 1200A Micrologic LI Trip Unit Settings LTPU LTD INST Existing Recommended Page 8 of 19

16 Relay/Breaker New PNL-2 Main Circuit Breaker Description Cutler-Hammer SBS-616, 1600A RMS520 LSI Trip Unit Settings LTPU LTD STPU STD INST GFPU GFD Recommended 1 (1600A) , I 2 t OFF (1200A) 0.4, I 2 T OFF Breaker LC-06 Feeder Circuit Breaker (In PNL-2) Description Cutler-Hammer HKD, RMS310+ LS trip unit, 400AF, 300AT Settings LTPU (I R ) LTD (t R ) STPU (I sd ) Recommended E (300) Relay/Breaker New PNL-1 Main Circuit Breaker (In PNL-2) Description Cutler-Hammer NGH, 1000A RMS 310+ LSI Trip Unit Settings LTPU LTD STPU STD INST (I R ) (t R ) (I sd ) (t sd ) Recommended G (1000A) ms, I 2 t OFF 12 Breaker LC-01 Feeder Circuit Breaker (In PNL-1) Description Cutler-Hammer HJD, 225A Settings Magnetic Trip Recommended 10 (2250A) Breaker LC-02 Feeder Circuit Breaker (In PNL-1) Description Cutler-Hammer HJD, 225A Settings Magnetic Trip Recommended 10 (2250A) Breaker LC-03 Feeder Circuit Breaker (In PNL-1) Description Cutler-Hammer HJD, 175A Settings Magnetic Trip Recommended 10 (1750A) Breaker LC-04 Feeder Circuit Breaker (In PNL-1) Description Cutler-Hammer HJD, 175A Settings Magnetic Trip Recommended 10 (1750A) Page 9 of 19

17 Breaker LC-05 Feeder Circuit Breaker (In PNL-1) Description Cutler-Hammer HJD, 175A Settings Magnetic Trip Recommended 10 (1750A) Time-Current Curve plots of protective devices analyzed in this study are included in Appendix B of this report. Page 10 of 19

18 4.0 ARC FLASH HAZARD STUDY 4.1 General The arc flash hazard study determines the incident energy and flash hazard boundary resulting from an arcing fault. Required PPE is then selected based on incident energy levels. Warning labels are then produced that identify arc flash hazards, approach boundaries, and PPE ratings to be worn by personnel working on the equipment while it is energized. Work on energized parts exceeding 50 volts to ground may only be done in accordance with Article of the 2015 NFPA 70E. Energized electrical conductors and circuit parts shall be put into an electrically safe work condition before an employee performs work if any of the following conditions exist: (1) The employee is within the limited approach boundary. (2) The employee interacts with equipment where conductors or circuit parts are not exposed but an increased likelihood of injury from an exposure to an arc flash hazard exists. The Arc Flash module of SKM Power Tools was used for calculation of incident energy. The IEEE 1584 calculation method was used, along with the guidelines in the 2015 edition of NFPA 70E as a basis for this study. Arc flash calculations require available three-phase bolted fault current values and protective device clearing times. SKM utilizes the three-phase bolted fault values computed in the short circuit study, and then determines arcing fault current. This arcing fault current is used to determine protective device clearing time based on time-current curves issued by the device manufacturer and stored in the SKM CAPTOR library. The SKM Arc Flash module scans the entire system topology, starting from the faulted bus out, to find the first protective device with an over-current trip curve. The upstream protective device(s) was also included in the search by selecting the "Check upstream devices for miscoordination" option within the SKM Arc Flash module. Upstream refers to the flow of power from the primary sources to the faulted location from the perspective of standing at the fault location. If there are multiple contributions to the faulted bus, the search process will be repeated until each contribution is cleared by its protective device, or the search reaches the end of the topology. Protection devices with a function name of "Ground" or "Neutral" were excluded from the protective device search. Using the arcing fault current and protective device clearing time, incident energy values are calculated by SKM based on IEEE 1584 and NFPA 70E standards. Page 11 of 19

19 4.2 SKM Arc Flash Module Calculation Assumptions Arc Flash calculations were performed using the short circuit current calculated by Solar City, and the values calculated by SCE. The worst-case incident energies from both cases were used. Calculation results are listed in Appendix C, along with a note describing which case produced the worst-case incident energy values. The trip time is determined from the TCC curves stored in the SKM CAPTOR library for all protective devices located in the branch that contains the faulted bus, and the device with the fastest trip time for the given arcing fault current is used. A constant working distance is assumed. The worker is stationary during the entire arc flash incident. When applying generic current-limiting fuse representation, the current-limiting range is assumed to start where the fuse clearing curve drops below 0.01 sec. When applying generic current-limiting fuse representation, fuses operating in the current limiting range are assumed to clear in ½ cycle for currents 1 to 2 times the current where the current-limiting range begins, and ¼ cycle for currents higher than 2 times the current where the current-limiting range begins. For purposes of the arc flash study, the interrupting device is rated for the available short circuit current. No equipment damage is considered due to the available fault current exceeding the protective device s interrupting rating. Equipment that is underrated for the available bolted fault current should be replaced with devices that meet or exceed the available bolted fault current in order to prevent equipment damage and injury to personnel. The next upstream protective devices were included in the search. The device that clears the arcing fault fastest is used. Ground fault and motor over load devices are excluded. For multi-function protective devices, only time and instantaneous phase overcurrent protective devices (ANSI devices 50 and 51) are used to determine the trip time. Only the larger incident energy based on low or high protective device tolerances is reported. When the total fault current cleared is less than the threshold percent specified in the study setup, or no upstream protective device is found, the bus is labeled as Dangerous and the incident energy and flash boundary are not reported. If the trip time obtained from the time current curve is larger than the maximum protection trip time defined in the study setup, the maximum protection trip time is used. Page 12 of 19

20 4.3 SKM Arc Flash Module Study Options Page 13 of 19

21 4.4 Arc Flash Hazard Study Results The following equipment had calculated incident energies above 8.0 cal/cm 2. Incident energies above 8.0 cal/cm 2 require personnel to wear arc flash hazard suits with an arc rating that matches or exceeds the incident energy calculated and printed on the arc flash warning label. Equipment Incident Energy Value ACDS-1 23 PNL-1 34 PNL-2 21 TR-1 Secondary 35 TR-2 Primary (480V) 15 For all equipment, personnel must use PPE with an arc rating that meets or exceeds the incident energy printed on the arc flash warning label. Note that the arc flash incident energies are valid only when the recommended circuit breaker settings in Section 3.3 are applied. The incident energies in the table above can not be reduced due to the impedance of transformers TR-1 and TR-2 reducing the available fault current, which increases the time required for protective devices to interrupt the arc. Incident energies at the equipment above also can not be reduced due to the lack of adjustable settings on devices such as thermalmagnetic circuit breakers or fuses. The relatively high hazard risk category at TR-1 and TR-2 exists on the exposed 480V lugs. In the event of an arc flash on the transformer 480V lugs, the Page 14 of 19

22 transformer s 12kV fuses would be called upon to interrupt the arc. The transformer s impedance results in a lower magnitude of fault current seen by the primary fuses, which results in an increased opening time of the fuses, longer arc duration, and more heat energy released from the arc. The Hazard Risk Category can not be reduced because the transformer primary fuses have been selected by the manufacturer. The primary fuses must be properly sized to accommodate the transformer s inrush current. Smaller fuses may not withstand the inrush current of the transformer. Replacement of the backup current-limiting fuses requires transformer disassembly. Therefore, reduction of the Hazard Risk Category by changing the protective devices is not feasible. Installation of insulating shields over the exposed 480V terminals within the transformer compartment will help prevent accidental contact with exposed energized parts, and reduce the chances of an arc flash occurring within the transformer s 480V compartment. Insulating boots can be installed over the transformer lugs, or a sheet of insulating material such as fiberglass could be installed in the compartment. Drop-on insulating boots that cover the transformer 480V terminals are available from manufacturers such as Thomas and Betts. The Arc Flash Hazard at the transformer 480V terminals can also be avoided by de-energizing the transformer from an upstream disconnect. At PNL-1 and PNL-2, insulating shields that protect the terminals of the main circuit breakers are available from Eaton/Cutler-Hammer, the manufacturer of the equipment installed as part of this project. Insulating shields should be installed over the circuit breaker terminals if they are not already provided from the factory. Since the photovoltaic system will be tapped into the line side of Switchboard MSB main breaker, there is no 480V protection at this tap. The tap, from the point of connection to the 1600A fused disconnect, should NOT be exposed while the systems are energized. Warning labels advising against access to the tap while the system is energized should be affixed at the point of the tap. Southern California Edison (SCE) should be contacted to disconnect service prior to starting work on the tap at the line side of the 1600A disconnect. SCE requirements for the interconnection of the photovoltaic system may require this tap to be sealed by the utility, preventing access by facility personnel. No energized work shall be performed on the service entrance equipment and conductors, or the line side of the main circuit breaker. Contact Southern California Edison to perform deenergization of services before starting work on the line side of a service main circuit breaker. In order for the Arc Flash Hazard study results to be valid, the recommended protective device settings for the main circuit breaker should be programmed and tested by a qualified electrical testing company. Refer to Appendix C of this report for complete Arc Flash calculations performed at each equipment location included in this study. Page 15 of 19

23 5.0 PROJECT RECOMMENDATIONS 1. Apply Recommended Protective Device Settings It is recommended to program circuit breaker settings given in Section 3.3 of this report. Applying the recommended protective device settings in Section 3.3 of this report will provide optimal device coordination between the main and feeder circuit breakers, while minimizing arc flash incident energies. 2. De-energized Electrical Work Policy Establish the policy of working on electrical equipment that has been de-energized whenever feasible. The directive for avoiding work on energized equipment is listed in NFPA 70E - Standard for Electrical Safety in the Workplace -Justification for Work. Live parts to which an employee might be exposed shall be put into an electrically safe work condition before an employee works on or near them, unless the employer can demonstrate that de-energizing produces additional or increased hazards or is infeasible due to equipment design or operational limitations. Working on electrical equipment that has been established as being in an electrically safe condition, in accordance with NFPA 70E, Article 120, eliminates the Arc Flash hazard and electrical shock hazard for most electrical equipment. By working on de-energized equipment whenever feasible, the exposure of personnel to Arc Flash and shock hazards is reduced. 3. Develop Arc Flash Hazard Management Program 1) PPE with a minimum Arc Thermal Performance Value (ATPV) of 8 calories is recommended as daily wear for qualified employees routinely involved in electrical maintenance. 2) PPE suitable for work on equipment with higher incident energies than 8 calories must be provided. 3) Determine training requirements for various employee work responsibilities. Identify qualified employees versus unqualified employees, and develop electrical safety training tailored to the qualifications of employees. 4) Determine and publish Arc Flash Hazards Management Program policies. 5) Implement program. Page 16 of 19

24 4. Require and implement PPE and Protective Measure Policies against Arc Flash Hazards Provide and require employees to practice and implement policies for use of proper Personal Protective Equipment (PPE) for work in all areas of Arc Flash hazards, as required by the facility Arc Flash Hazard Management Program. Qualified employees properly wearing PPE according to the calculated incident energy will mitigate injuries experienced by an arc flash. Employers must provide workers with appropriate PPE as per the OSHA (h)(1) PPE payment requirement, i.e., (PPE) used to comply with this part, shall be provided by the employer at no cost to employees. Paragraph (h) became effective February 13, 2008, and employers must implement the PPE payment requirements no later than May 15, Provide clearly visible Arc Flash boundary markings so personnel know when they are entering an Arc Flash zone and the PPE required prior to entering the Arc Flash zone (movable cones, tape, etc.). Boundary markings will help prevent unqualified personnel from entering an Arc Flash or shock hazard boundary while work is performed on energized equipment. 5. Project Validation and Maintenance In order to maintain a safe and compliant facility, it is imperative that the Arc Flash study is updated as changes are made to the electrical distribution system. Changes in the electrical system including impedance, protective device settings, and short circuit duties will affect the incident energy values calculated in this report. As a result, changes in the electrical system will invalidate these values. Procedures for keeping this analysis up-to-date include, but are not limited to, updating the single-line diagrams for the electrical distribution system, recalculating the Short Circuit Study, the Coordination Study and the Arc Flash Hazard Assessment and updating the equipment warning labels to incorporate the latest results. Perform a complete review of all engineering studies performed as part of this Power System Analysis at a minimum of every 5 years, or as required by future NFPA 70E requirements. The review should include all recorded changes to the electrical infrastructure. If there are changes to hazard levels, then equipment should be re-labeled appropriately. Inaccurate incident energies and insufficient PPE can result in serious injury to personnel. By keeping the Arc Flash Hazard Analysis valid and up-to-date, personnel can use proper safety equipment to mitigate hazards. The risk of injury to personnel is minimized when employees have the knowledge of the dangers in the workplace and utilize the right safety equipment to diminish those dangers. Page 17 of 19

25 6. Provide Training of Arc Flash/Shock Hazards to Workers Provide adequate training and rules governing the work and hazards on all electrical equipment for both Qualified and Unqualified employees. Personnel must be adequately trained to read Arc Flash/Shock hazard warnings and how to prepare themselves for the dangers of an Arc Flash/Shock hazard. By providing training, hazard notification, and PPE, the electrical system will be compliant with OSHA and NFPA regulations regarding Arc Flash hazards as of this report date. The risk of injury to employees as a result of shock/arc flash will be mitigated when employees are aware of hazards and have taken necessary precautions for working on electrical equipment, including, but not limited to, wearing proper PPE and establishing approach boundaries. 7. Develop an Overcurrent Protective Device (OCPD) Management Program Implement a comprehensive OCPD Management Program. Establish a Circuit Breaker Maintenance program in accordance with manufacturer s recommendations for testing and maintenance. Require all future maintenance and replacement of fuses and circuit breakers to use the same make and model number for replacement components. The Arc Flash Hazard study depends on operation of the protective devices as shown on the manufacturer s TCC curves. These devices may be normally inactive for long periods. It is essential that all protective devices and associated relays and sensors are tested and calibrated at regular intervals, as recommended by the manufacturer. The calculated Arc Flash hazard levels in the facility electrical distribution system are dependent on the fault clearing times of the actual fuse types (UL Classifications) and circuit breaker types and their trip settings installed in the system. All maintenance changes to OCPDs must be recorded in writing, i.e., red-lined drawings and drawing revisions. In order to maintain the integrity of this Arc Flash Study, all changes to OCPDs will require future re-calculation of incident energy levels to determine new hazard levels. OCPD coordination in the electrical distribution system is dependent on the fuses, circuit breakers and trip settings currently installed, and recommended. Replacement of protective devices with units that are not identical will affect system protection device coordination, and may adversely affect incident energies calculated in this report. A documented program of scheduled circuit breaker testing and maintenance will ensure that the circuit breakers are in operational condition and that they will function properly during a short circuit condition. Periodic testing of circuit breakers and associated relays ensures proper operation of the circuit breaker s protective function. Without circuit breaker maintenance, Arc Flash Hazards can increase significantly over time due to slow opening response times of dirty or worn mechanisms, even with no changes to the electrical system. Page 18 of 19

26 8. Equipment Maintenance Buildup of debris in equipment enclosures poses a risk of a short circuit, flashover, and/or equipment failure. In addition, electrical connections can become loose over time. Loose electrical connections can cause high-resistance heating of conductors and connecting devices, and pose a fire hazard. The protective device operating mechanism must be lubricated and exercised to assure proper operation. Periodically de-energize and operate protective equipment and perform maintenance as recommended in 2013 NFPA 70B, Recommended Practice for Electrical Equipment Maintenance. Clean interior of equipment enclosures. Check bolted connections for proper torque, that all electrical connections are secure, and perform any other maintenance per manufacturer s instructions. Maintain a log of maintenance and inspections performed. Page 19 of 19

27 APPENDIX A SHORT CIRCUIT INPUT DATA, CALCULATION RESULTS DAPPER Fault Analysis Input Report (English) CASE 1 Utilities Contribution Bus In/Out Nominal Contribution Data PU (100 MVA Base) From Name Name Voltage Duty Units X/R R PU X PU TEMEC SCE SERVICE BUS-0048 In 480 3P: 64,174 Amps 3.53 Pos: SLG: 64,174 Amps 4.16 Zero: Cables Cable From Bus In/Out Qty Length Cable Description Per Unit (100 MVA Base) Name To Bus Service /Ph Feet Size Cond. Type Duct Type Insul R pu jx pu BUS-TEMEC MSB2 BUS-0048 In Copper Busway Epoxy Pos: TEMEC MAIN S Zero: BUS-TEMEC PNL-2 TEMEC ACDS-1 In Copper Busway Epoxy Pos: TEMEC PNL-2 Zero: CBL-TEMEC AC-01 TEMEC TR-1 SEC In Copper Magnetic PVC Pos: TEMEC PNL-1 Zero: CBL-TEMEC AC-02 TEMEC PNL-2 In Copper Magnetic PVC Pos: TEMEC TR-2 S Zero: CBL-TEMEC AC-03 BUS-0048 In Copper Magnetic PVC Pos: TEMEC ACDS-1 Zero: CBL-TEMEC AC-MV TEMEC TR-2 PRI In 1 1,300 1 Copper Non-Magnetic EPR Pos: TEMEC TR-1 PR Zero: CBL-TEMEC GATEW TEMEC MONITOR In Copper Magnetic PVC Pos: TEMEC GATEWA Zero: CBL-TEMEC INV 1A TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1A Zero: CBL-TEMEC INV 1B TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1B Zero: CBL-TEMEC INV 1C TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1C Zero: CBL-TEMEC INV 1D TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1D Zero: CBL-TEMEC INV 1E TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1E Zero: CBL-TEMEC INV 1F TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1F Zero: Page A - 1

28 CBL-TEMEC INV 1G TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1G Zero: CBL-TEMEC INV 1H TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1H Zero: CBL-TEMEC INV 1I TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1I Zero: CBL-TEMEC INV 1J TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1J Zero: CBL-TEMEC INV 1K TEMEC LC-03 In Copper Non-Magnetic PVC Pos: TEMEC INV 1K Zero: CBL-TEMEC INV 1L TEMEC LC-03 In Copper Non-Magnetic PVC Pos: TEMEC INV 1L Zero: CBL-TEMEC INV 1 TEMEC LC-03 In Copper Non-Magnetic PVC Pos: TEMEC INV 1M Zero: CBL-TEMEC INV 1N TEMEC LC-03 In Copper Non-Magnetic PVC Pos: TEMEC INV 1N Zero: CBL-TEMEC INV 1O TEMEC LC-04 In Copper Non-Magnetic PVC Pos: TEMEC INV 1O Zero: CBL-TEMEC INV 1P TEMEC LC-04 In Copper Non-Magnetic PVC Pos: TEMEC INV 1P Zero: CBL-TEMEC INV 1Q TEMEC LC-04 In Copper Non-Magnetic PVC Pos: TEMEC INV 1Q Zero: CBL-TEMEC INV 1R TEMEC LC-04 In Copper Non-Magnetic PVC Pos: TEMEC INV 1R Zero: CBL-TEMEC INV 1S TEMEC LC-05 In Copper Non-Magnetic PVC Pos: TEMEC INV 1S Zero: CBL-TEMEC INV 1T TEMEC LC-05 In Copper Non-Magnetic PVC Pos: TEMEC INV 1T Zero: CBL-TEMEC INV 1U TEMEC LC-05 In Copper Non-Magnetic PVC Pos: TEMEC INV 1U Zero: CBL-TEMEC INV 1V TEMEC LC-05 In Copper Non-Magnetic PVC Pos: TEMEC INV 1V Zero: CBL-TEMEC INV 2A TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2A Zero: CBL-TEMEC INV 2B TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2B Zero: CBL-TEMEC INV 2C TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2C Zero: CBL-TEMEC INV 2D TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2D Zero: Page A - 2

29 CBL-TEMEC INV 2E TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2E Zero: CBL-TEMEC INV 2F TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2F Zero: CBL-TEMEC INV 2G TEMEC LC-06 In Copper Non-Magnetic PVC Pos: TEMEC INV 2G Zero: CBL-TEMEC LC-01 TEMEC PNL-1 In /0 Copper Magnetic PVC Pos: TEMEC LC-01 Zero: CBL-TEMEC LC-02 TEMEC PNL-1 In /0 Copper Magnetic PVC Pos: TEMEC LC-02 Zero: CBL-TEMEC LC-03 TEMEC PNL-1 In /0 Copper Magnetic PVC Pos: TEMEC LC-03 Zero: CBL-TEMEC LC-04 TEMEC PNL-1 In /0 Copper Magnetic PVC Pos: TEMEC LC-04 Zero: CBL-TEMEC LC-05 TEMEC PNL-1 In Copper Magnetic PVC Pos: TEMEC LC-05 Zero: CBL-TEMEC LC-06 TEMEC PNL-2 In Copper Magnetic PVC Pos: TEMEC LC-06 Zero: CBL-TEMEC METE TEMEC METER In Copper Magnetic PVC Pos: TEMEC TR-2 S Zero: CBL-TEMEC MON TEMEC PNL-2 In Copper Magnetic PVC Pos: TEMEC MONITOR Zero: CBL-TEMEC PNL-1 TEMEC PNL-1 MO In Copper Magnetic PVC Pos: TEMEC PNL-1 G Zero: CBL-TEMEC PNL-1 TEMEC PNL-1 In Copper Magnetic PVC Pos: TEMEC PNL-1 M Zero: Winding Transformers Xformer In/Out Primary & Secondary Nominal Z PU (100 MVA Base) Name Service Bus Conn. Volts FLA kva R pu jx pu TEMEC GATEWAY XF In TEMEC GATEWAY DI D Pos: , TEMEC GATEWAY WG Zero: , TEMEC PNL-1 GATEW In TEMEC PNL-1 GATEW D Pos: , TEMEC PNL-1 GATE WG Zero: , TEMEC TR-1 In TEMEC TR-1 PRIMAR D 12, Pos: TEMEC TR-1 SECON WG 480 1,010 Zero: TEMEC TR-2 In TEMEC TR-2 PRIMAR D 12, Pos: TEMEC TR-2 SECON WG 480 1,010 Zero: Page A - 3

30 ***************** F A U L T A N A L Y S I S S U M M A R Y CASE 1***************** BUS NAME VOLTAGE AVAILABLE FAULT CURRENT L-L 3 PHASE X/R LINE/GRND X/R TEMEC ACDS TEMEC GATEWAY DISC SW TEMEC INV 1A TEMEC INV 1B TEMEC INV 1C TEMEC INV 1D TEMEC INV 1E TEMEC INV 1F TEMEC INV 1G TEMEC INV 1H TEMEC INV 1I TEMEC INV 1J TEMEC INV 1K TEMEC INV 1L TEMEC INV 1M TEMEC INV 1N TEMEC INV 1O TEMEC INV 1P TEMEC INV 1Q TEMEC INV 1R TEMEC INV 1S TEMEC INV 1T TEMEC INV 1U TEMEC INV 1V TEMEC INV 2A TEMEC INV 2B TEMEC INV 2C TEMEC INV 2D TEMEC INV 2E TEMEC INV 2F TEMEC INV 2G TEMEC LC TEMEC LC TEMEC LC TEMEC LC TEMEC LC Page A - 4

31 ***************** F A U L T A N A L Y S I S S U M M A R Y CASE 1***************** BUS NAME VOLTAGE AVAILABLE FAULT CURRENT L-L 3 PHASE X/R LINE/GRND X/R TEMEC LC TEMEC MAIN SWGR TEMEC METER TEMEC MONITOR J-BOX TEMEC PNL TEMEC PNL-1 GATEWAY DISC SW TEMEC PNL-1 MONITOR J-BOX TEMEC PNL TEMEC TR-1 PRIMARY TEMEC TR-1 SECONDARY TEMEC TR-2 PRIMARY TEMEC TR-2 SECONDARY *********************** FAULT ANALYSIS REPORT COMPLETED ********************************* Page A - 5

32 DAPPER Fault Analysis Input Report (English) CASE 2 Utilities Contribution Bus In/Out Nominal Contribution Data PU (100 MVA Base) From Name Name Voltage Duty Units X/R R PU X PU TEMEC SCE SERVICE BUS-0048 In 480 3P: 25,500 Amps 5.25 Pos: SLG: 27,300 Amps 6.22 Zero: Cables Cable From Bus In/Out Qty Length Cable Description Per Unit (100 MVA Base) Name To Bus Service /Ph Feet Size Cond. Type Duct Type Insul R pu jx pu BUS-TEMEC MSB2 BUS-0048 In Copper Busway Epoxy Pos: TEMEC MAIN S Zero: BUS-TEMEC PNL-2 TEMEC ACDS-1 In Copper Busway Epoxy Pos: TEMEC PNL-2 Zero: CBL-TEMEC AC-01 TEMEC TR-1 SEC In Copper Magnetic PVC Pos: TEMEC PNL-1 Zero: CBL-TEMEC AC-02 TEMEC PNL-2 In Copper Magnetic PVC Pos: TEMEC TR-2 S Zero: CBL-TEMEC AC-03 BUS-0048 In Copper Magnetic PVC Pos: TEMEC ACDS-1 Zero: CBL-TEMEC AC-MV TEMEC TR-2 PRI In 1 1,300 1 Copper Non-Magnetic EPR Pos: TEMEC TR-1 PR Zero: CBL-TEMEC GATEW TEMEC MONITOR In Copper Magnetic PVC Pos: TEMEC GATEWA Zero: CBL-TEMEC INV 1A TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1A Zero: CBL-TEMEC INV 1B TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1B Zero: CBL-TEMEC INV 1C TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1C Zero: CBL-TEMEC INV 1D TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1D Zero: CBL-TEMEC INV 1E TEMEC LC-01 In Copper Non-Magnetic PVC Pos: TEMEC INV 1E Zero: CBL-TEMEC INV 1F TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1F Zero: CBL-TEMEC INV 1G TEMEC LC-02 In Copper Non-Magnetic PVC Pos: TEMEC INV 1G Zero: CBL-TEMEC INV 1H TEMEC LC-02 In Copper Non-Magnetic PVC Pos: Page A - 6