2019-11-8 DRAFT - AFHA Survey.pdf

HZA Engineering, LLC Mechanical & Electrical Consulting Engineers

113 W. Northern Lights Blvd, Suite 240 • Anchorage, Alaska 99503 Tel 907 562 1012 • Fax 907 562 1013 • www.hza-eng.com

Arc-Flash Hazard Analysis and Electrical Survey Buildings 2228, 2222, A072, CE46817, 5223

2204, 2212, & 2218 JBER, Alaska

DRAFT – November 8th, 2019

AFHA and Electrical Survey U.S. Army Engineer District, AK Contract No. W911KB-17-D-0013

Delivery Order No. W911KB19F0079 Tasks 1, 2, 3, 4, & 5

Arc-Flash Hazard Analysis and Electrical Survey Contract # W911KB-17-D-0013 Buildings 2228, 2222, A072, CE46817, 5223, Delivery Order # W911KB19F0079 2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -1

TABLE OF CONTENTS

Building 2228 Section A

Building 2222 Section B

Building A072 Section C

Building CE46817 Section D

Building 5223 Section E

Building 2204 Section F

Building 2212 Section G

Building 2218 Section H

Buildings 2228, 2222, A072, CE46817, 5223

Section A – Building 2228

Contract No. W911KB-17-D-0013

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Arc-Flash Hazard Analysis and Electrical Survey Section A - Building 2228

1. Executive Summary 3

1.1 Overview 3

1.2 Short-Circuit 3

1.3 Coordination 3

1.4 Arc-Flash 3

1.5 System Observations 4

2 Introduction 5

3 Electrical Systems Description 6

4 Short-Circuit Analysis 7

4.1 General Procedures 7

4.2 Utility Transformer Data 8

4.3 Cable Data 8

4.4 Assumptions and Estimates 8

4.5 Short-Circuit Analysis – Results and Recommendations 9

5 Overcurrent Device Coordination Study 10

5.1 General Procedures 10

5.2 Molded Case Circuit Breakers 11

5.3 Selective Coordination Considerations 12

5.4 Selective Coordination Analysis – Results and Recommendations 13

6 Arc-Flash Hazard Analysis 14

6.1 General Procedures 14

6.2 Risk Assessment and Control 15

6.3 Hazard Categories 15

6.4 Labels 17

6.5 Arc-Flash Hazard Analysis – Results and Recommendations 18

7 Non-Destructive Inspection 20

7.1 General 20

7.2 Circuit Tracing 20

7.3 Cable Protection 21

7.4 System Deficiencies 21

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -2

Appendix A: Electrical Distribution System Riser Diagram – Existing Configuration Appendix B: Short Circuit Input Data Appendix C: Short Circuit Analysis - Riser Diagram Appendix D: Overcurrent Device Coordination Analysis – Existing Settings Appendix E: Overcurrent Device Coordination Analysis – Recommended Settings Appendix F: Overcurrent Protection Device – Existing Settings Appendix G: Overcurrent Protection Device – Recommended Settings Appendix H: Arc-Flash Results – Existing Settings Appendix I: Arc-Flash Results – Recommended Settings Appendix J: Photolog/Arc-Flash Labels Appendix K: Non-Destructive Inspection Appendix L: Panel Schedules Appendix M: Cost Estimate

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -3

1. Executive Summary

1.1 Overview

This report documents the results of an Arc-Flash Hazard Analysis, Electrical Survey, Non- Destructive Inspection, and Circuit Tracing for Building 2228 of the USACE district headquarter facilities at JBER, Alaska. The objective of this section is to briefly outline the results of the analysis and highlight issues and findings discovered while analyzing the building’s electrical distribution system. The full analysis is found in the main body of this report.

1.2 Short-Circuit

The maximum available fault current is the short-circuit current that occurs when all phase conductors are shorted together and reflects the worst-case short-circuit scenario. Overcurrent protective devices are intended to interrupt fault currents and are to have interrupting ratings not less than the maximum available fault current calculated at that location. Likewise, switchboards, panelboards, and electrical equipment are intended to be rated to withstand the maximum available fault current at their terminals or bus bars to minimize damage or danger to personnel until the circuit breakers trip and clear the fault.

Of the electrical devices evaluated for Building 2228, all were found to be adequately rated to interrupt or withstand the maximum available fault current that was calculated.

1.3 Coordination

Selective coordination is meant to isolate a fault to the circuit breaker or fuse closest to the fault.

Selective coordination requires that upstream circuit breakers hold until the downstream circuit breaker trips and clears the fault.

Selective coordination is not required by the National Electrical Code (NEC) for the electrical overcurrent protective devices in Building 2228, and we do not recommend any coordination efforts, as complete coordination cannot be easily achieved without replacing equipment.

1.4 Arc-Flash

An arc-flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. Arc-flashes at higher available fault currents can produce enough energy to vaporize metal and cause severe burns with sufficient blast pressure to break bones or worse. The magnitude of the available arcing fault current and the length of time the fault current is available before the overcurrent protective device operates are two components that affect arc-flash energy levels.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -4

An incident energy value of 1.2 cal/cm2 is considered the threshold of second-degree burns, while incident energy values of approximately 8-12 cal/cm2 are considered the boundary line between “low” and “high” Personal Protective Equipment (PPE) levels, and incident energy levels of 40 cal/cm2 are considered as “maximum allowable”. Many employers have used this level of 40 cal/cm2 as a threshold above which no energized work is to be performed under any conditions due to the increased risk of non-burn injuries (hearing damage, etc.).

We analyzed the system under existing conditions and found that all of the electrical devices’ incident energy levels were under 2 cal/cm2.

We do not offer any recommendations to lowering the arc-flash incident levels. Qualified electrical workers will need to select appropriate PPE when working on this equipment.

1.5 System Observations

Additionally, code and safety issues were noted during the site investigation, non-destructive inspection, and analysis of Building 2228. The electrical system is not connected to a grounding electrode system, a ground bar is missing, and equipment grounding conductors are terminated under panel mounting screws.

We recommend installing a properly sized, bonded, and terminated grounding electrode system, with a ground bar and terminating equipment grounding conductors.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -5

2. Introduction

HZA Engineering performed an arc-flash hazard analysis and electrical survey of the existing electrical distribution systems at the USACE Headquarter facilities, Buildings 2228, 2222, A072, CE46817, and 5223 at JBER, Alaska. Non-destructive inspection and circuit tracing of the existing electrical distribution systems were also performed for these same buildings as well as for Buildings 2204, 2212, and 2218. The arc-flash hazard analysis and electrical survey for Buildings 2204, 2212, and 2218 have previously been completed and provided to the Contracting Officer’s Representative in a separate report dated February 13th, 2019. Data acquired for this analysis was obtained by NPC Energy Services during the days of May 28th through June 7th, 2019. This particular section specifically details the findings and recommendations for Building 2228. Buildings 2222, A072, CE46817, 5223, 2204, 2212, and 2218 will be addressed in separate sections. The latest version of SKM Power Tools software was used to perform the study.

The study includes a short-circuit analysis, overcurrent device time-current coordination analysis, arc-flash hazard analysis, adverse findings and safety concerns of the building’s existing electrical systems, and an updated electrical distribution single line diagram showing the calculated available fault current and device interrupting rating at each electrical bus. Arc-flash labels with equipment specific safety information [will be] [have been] provided and installed at the existing electrical equipment for qualified personnel to determine safe working requirements prior to working on the electrical equipment. Additionally, updated panel schedules [will be] [have been] provided and installed at each panelboard.

Arc-flash labels were based on existing conditions and settings, as it is recognized that recommendations in this report may not be implemented immediately in full. It should be noted that modification of equipment, changes to the system configuration, adjustment of protective device settings, or failure to properly maintain equipment may invalidate these results and labels will need to be updated.

The following report outlines the findings, study results, recommendations for better overcurrent protective device coordination, arc-flash hazard mitigation solutions, and safety upgrades in more detail; as well as cost estimates to implement the recommendations.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -6

3. Electrical System Description

Building 2228 is fed from one 15 kVA, pole mounted transformer with a secondary voltage of 120/240 volts, single phase. The secondary feeders are installed overhead to the building, connected to a weather head, and then down the mast to the panel inside the building. The feeders are terminated on a back fed two-pole 60 amp main breaker in a 100 amp rated panel (Panel CS – 9800).

See also Appendix A: Electrical Distribution System Riser Diagram – Existing Configuration.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -7

4. Short-Circuit Analysis

4.1 General Procedure

The maximum available fault current is the short-circuit current that occurs when all phase conductors are shorted together and reflects the worst-case short-circuit scenario. Overcurrent protective devices are intended to interrupt fault currents and are to have interrupting ratings not less than the maximum available fault current at that location. Likewise, switchboards, panelboards and electrical equipment are intended to be rated to withstand the maximum available fault current at their terminals or bus bars to minimize damage or danger to personnel until the circuit breakers trip and clear the fault.

This electrical system short-circuit analysis is used to compare the calculated maximum available fault current with the interrupting ratings of overcurrent protective devices such as fuses and circuit breakers; to verify the adequacy of other equipment, such as switches and equipment bussing; to withstand the effects of the calculated maximum fault current levels; to assist in the selection and/or determination of settings for relays, fuses, and circuit breakers; and to provide input for the arc-flash hazard analysis.

As part of this analysis, the maximum available line-to-line, RMS symmetrical, short-circuit amperes at each piece of electrical equipment in the system is calculated. The calculation procedures are based on recommendations included in applicable ANSI/IEEE standards. The SKM Power Tools software simulates a bolted line-to-line fault at the electrical equipment (switchboards, panelboards, transfer switches, etc.) and calculates the maximum available short-circuit or fault current at that point without any reduction due to current-limiting overcurrent devices which may be present. The calculated available fault current values are RMS symmetrical amperes and are comparable with the RMS symmetrical short-circuit ratings of electrical equipment.

Electrical distribution equipment must be able to withstand and/or interrupt the most severe fault duty that it may be subjected to at its location in the system. In particular, NEC Section 110.9 requires circuit breakers to have a rating sufficient for interrupting the maximum available fault current present at their line side terminals. Where calculated fault currents exceed the ratings of the equipment, recommendations for corrective actions are provided.

Equipment short-circuit withstand and interrupting ratings are expressed in symmetrical RMS current. However, fault currents are not purely symmetrical in practice, as system inductance introduces a degree of asymmetry for at least the first few cycles of a fault. The magnitude and duration of this asymmetrical component depends on several factors, including characteristics of system components (conductors, transformers, and loads) and the exact point on the current waveform that the fault begins—the level of asymmetry even differs from phase to phase in a multi-phase system. Because of the uncertainty in asymmetry for a given fault event, the capability of

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -8 devices to interrupt asymmetrical fault current is based on the maximum possible asymmetrical fault current level at the point of application. The more inductive the circuit, as measured by the X/R ratio, the more asymmetrical the fault current can be. If the calculated X/R ratio exceeds a certain level, then the increased asymmetrical duty must be considered when breaker ratings are assessed.

4.2 Utility Transformer Data

For Building 2228, the electrical utility company provided us with the available fault current (5,601A three-phase and 5,238A line-to-ground) at the line side of the transformer, transformer rat-ing (15kva), impedance (2.8%Z), secondary voltage (120/240V, single phase), secondary conductor quantity, size, and material type (1 run of #2 Triplex aluminum, 75’; 1 run of #6 AWG copper, 15’).

This information, along with the building cable data mentioned below, was the basis used for deter-mining the available fault current throughout the building’s electrical system.

4.3 Cable Data

Conductor and raceway information for each feeder segment including quantity per phase, size, conductor material, insulation type, conduit type, and length were entered into the calculation model and can be referenced in the riser diagram, see Appendix B: Short Circuit Input Data.

4.4 Assumptions and Estimates

Some assumptions and estimates were required and may affect the results of this study.

Assumptions or estimates are needed because of limited access, safety concerns in obtaining equipment nameplate data, or lack of documentation. The following assumptions, or estimates, were made for the reasons given above:

1. Motor loads less than 50hp were not included, since these smaller motor loads contribute an insignificant increase in short-circuit current and can be neglected according to IEEE 141- “Recommended Practice for Electric Power Distribution and Coordination of Industrial and Commercial Power Systems”, (Red Book).

2. Conductor lengths were determined from the as-built plans provided, approximating the length between electrical components (feeder panel to downstream panel).

3. Conductor sizes were determined from visual inspection.

4. Unless otherwise visible, the conductors were assumed to be installed in metallic conduit.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -9

4.5 Short-Circuit Analysis - Results and Recommendations

After performing the short-circuit calculations, the existing electrical equipment was analyzed to determine its adequacy to interrupt or withstand the effects of the calculated maximum short-circuit current at the installed locations. For some solidly grounded systems, there is a potential that the bolted line-to-line fault current may not result in the maximum fault current. For this reason, the larger of the calculated bolted line-to-line fault current was compared with the calculated bolted line-to-ground fault current at each electrical component and the larger of the two was used for evaluating that panel’s adequacy. Calculated maximum fault currents can be seen in Appendix C:

Short Circuit Analysis – Riser Diagram.

Comparing the calculated fault currents to the Ampere Interrupt Ratings (AIR) of the circuit breakers at Building 2228 confirms that all of the equipment examined was identified as adequate to interrupt or withstand the maximum short-circuit current to which they could be subjected.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -10

5. Overcurrent Device Coordination Study

5.1 General Procedure

Selective coordination is meant to isolate a fault to the circuit breaker or fuse closest to the fault.

Selective coordination requires that the upstream circuit breakers hold until the downstream circuit breaker trips and clears the fault.

A coordination study is a procedure to examine an electrical system, specifically the overcurrent protective devices, with the goal of ensuring that they are properly rated and adjusted to provide protection and maximum service continuity.

System coordination requires that the overcurrent protection devices be rated, selected, and adjusted to allow the normal load currents to flow while quickly opening the circuit when a short-circuit, overload, or fault occurs. System coordination is optimized when the overcurrent protective device nearest the fault opens and isolates the faulted circuit from the electrical distribution system while keeping the remaining system in operation. When a system is selectively coordinated the overcurrent protection device must isolate the fault for the full range of available overcurrents, from overload to the maximum available fault current and for the full range of overcurrent protective device opening times associated with those currents. Selective coordination is practically impossible to achieve with standard molded case circuit breakers with “fixed” trip settings. Selective coordination typically requires the use of circuit breakers with adjustable long- & short-time delay settings and larger frame sizes to be used farther from the load or fuses to be used nearer the load.

Selectively coordinated protective devices farther from the load typically perform as a backup protection for the devices nearer to the fault and consequently must be able to hold the fault current for the time period the over current device nearest the fault takes to open. This may allow longer duration faults when the point is nearer to the service entrance equipment.

Selection and setting of the overcurrent devices are determined from comparing the time-current curves of the various devices in series on a log-log graph. This procedure considers boundaries defined by load current, short-circuit currents, and ANSI and NEC requirements.

Coordination is obtained when each device’s time-current curve shows sufficient clear space or no overlap between the curves for the protective devices operating in series. The time-current curves are plotted along the fault current axis until the maximum available fault current is achieved for the device. Selective coordination is achieved when the curves do not overlap up to the level of the maximum available fault current indicated where the time-current curve for each device ends on the short-circuit current axis.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -11

5.2 Molded Case Circuit Breakers

Molded case circuit breakers typically will not fully coordinate into the instantaneous region (approximately half cycle) unless time delays are provided in the circuit breakers further from the load. This condition is indicated in Figure 1 where circuit breaker B overlaps with circuit breaker A in the instantaneous region. Circuit breaker C is fully coordinated with circuit breakers A & B since the time-current characteristic curve for circuit breaker C does not overlap for the full range of fault currents from the instantaneous fault region (initial period from 0 to a few milli-seconds), through the short-time fault region (middle region from a fraction of a second to a few seconds), to the long-time fault region (usually ranging from many seconds to multiple minutes).

Figure 1 – Example Molded Case Circuit Breaker Coordination

Greater separation between the instantaneous settings may increase the likelihood that the two devices will operate selectively. The potential lack of selective coordination is generally not considered critical, and can be avoided by adopting a different and, in general, less economical design, especially when the following are considered:

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -12

1. Most faults occur in equipment such as motors, lighting panels, and process control panels which typically are located at the end of branch circuits, significantly reducing fault level and thereby reducing or eliminating the possibility of non-selective operation.

2. Lower magnitude arcing faults in rotating machinery and lighting panels are statistically more common than bolted line-to-line faults.

3. Ground faults are more common than line-to-line faults.

4. Maximum fault current is a random event depending on the point-on-wave of which the fault occurs. Other factors include X/R ratio, power factor, frequency, phase angle, and magnitude of the symmetrical fault current.

5. The device cutoff points on time-current curve graphs are based on bolted fault current levels which correspond to zero impedance. Typical fault current impedance is usually greater than zero so the actual fault current seen by overcurrent devices can be less than what is shown on the time-current curve graphs.

5.3 Selective Coordination Considerations

The objective is to determine the best coordination for the entire system, however, selective coordination is not always considered essential or economically viable unless required for the continuation of the electrical service for safety considerations.

Selective coordination is often difficult to achieve when overcurrent devices with fixed settings are used. Selective coordination typically requires upstream panels to have larger bussing and circuit breaker frame sizes with adjustable circuit breaker settings. Greater selectivity generally requires longer holding times which can adversely affect arc-flash.

Coordination will often stop short of complete selectivity when an acceptable compromise is reached between the various boundaries imposed on the selecting and setting procedure. This approach necessitates tradeoffs in selectivity for some parts of the system to achieve maximum coordination in more critical areas.

The NEC does not require all electrical systems to be selectively coordinated in all facilities.

Instead, the NEC requires selective coordination for only a few electrical systems, such as: certain health care facilities, emergency power systems, legally required standby systems, critical operations power or data systems, and where multiple elevators are fed from a single feeder.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -13

5.4 Selective Coordination Analysis – Results and Recommendations

The results of the coordination study are the time-current curve graphs; which show the degree of coordination between each of the overcurrent protective devices connected in series in this electrical system. Smaller overcurrent devices with fixed time-current characteristics are not shown on the graphs unless they directly affect the setting of an adjustable upstream device.

It is our understanding that Building 2228 does not have the functions or electrical system features that the NEC requires to be selectively coordinated. The facility is fairly small and there is a minimal amount of electrical systems in the facility. As a result, the only coordination that can take place is between the main circuit breaker and the branch circuit breakers. Because these devices are similarly rated, there will be some overlap of the time-current curves. These existing circuit breakers have fixed settings and therefore the trip characteristics cannot be adjusted. In addition, it does not appear that adjustable setting circuit breakers are available for these panels with the desired ampere ratings. Coordination is not required and we do not recommend any coordination efforts as complete coordination cannot be easily achieved without replacing equipment.

See Appendix D: Overcurrent Device Coordination Analysis – Existing Settings for existing circuit breaker time-current curves and settings.

See Appendix E: Overcurrent Device Coordination Analysis – Recommended Settings for recommended circuit breaker time-current curves and settings.

See Appendix F: Overcurrent Protection Device – Existing Settings for existing circuit breaker settings.

See Appendix G: Overcurrent Protection Device – Recommended Settings for recommended circuit breaker settings.

For a cost estimate of these recommendations, see Appendix M: Cost Estimate.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -14

6. Arc-Flash Hazard Analysis

6.1 General Procedures

An arc-flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. Most faults occur during maintenance or during manual operation of the equipment, such as closing a circuit breaker under short-circuit or dropping a tool on the live bus bars, etc. The electrical arc lasts until the opening of the overcurrent protective device on the supply side of the fault. Arc-flashes at higher available fault currents can produce enough energy to vaporize metal and cause severe burns with sufficient blast pressure to break bones or worse. The magnitude of the available arcing fault current and the length of time the fault current is available before the overcurrent protective device operates are two components that affect arc-flash energy levels.

An arc-flash hazard analysis was performed for the existing electrical systems at Building 2228 to determine the arc-flash hazards that currently exist and provide recommendations to mitigate these hazards.

The arc-flash hazard analysis was calculated using SKM Power Tools with the IEEE 1584-2018 calculation method. The IEEE 1584 analysis procedure begins with a complete data collection of the existing power system. Characteristics of the power source – utility– and the power system components such as: transformers, cables, and the tripping characteristics of overcurrent protective devices, are all entered into the computer program. The program first calculates the bolted line-to-line short-circuit current at each bus of concern in the system. Then the arc-fault current is calculated at each bus location. Next, under the arc-fault current condition, the clearing time of the protective device protecting the bus is determined. For fuses, the manufacturer’s total clearing time is used. For low voltage breakers, the right-hand side of the manufacturer’s time-current curve is used. For relayed medium voltage breakers, the relay’s curve shows only the relay operating time, consequently, the particular breaker’s opening time must be added to this time. Following the clearing time determination, the working distance at each bus is selected. Next, incident energies are calculated for each bus. Incident energy is the amount of energy impressed on the face and body of the electrical worker. One of the units used to measure incident energy is calories per square centimeter (cal/cm2). The flash protection boundary based on an incident energy of 1.2 cal/cm2 is calculated. This is the generally accepted energy level that causes the onset of a second-degree burn.

Finally, the hazard risk category and the worker’s personal protection equipment (PPE) for each bus under consideration are determined.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -15

6.2 Risk Assessment and Control

NFPA 70E indicates a “hierarchy of controls” when controlling risk.

1. This hierarchy prioritizes the elimination of the hazard as the first priority. For electrical hazards, this typically means removing unnecessary equipment or eliminating the need to expose energized parts. It can also mean de-energizing equipment and creating an electrically safe condition which also eliminates electrical hazards.

2. When hazard elimination is not possible, the next priority is substitution. For example, this may mean replacing older electrical equipment with newer equipment designed to reduce risk.

3. The third risk control method in the hierarchy of controls is engineering controls. For electrical hazards, engineering controls may be the addition of cover plates, shielding to prevent exposure to energized parts, or simply changing circuit breaker trip settings.

4. The fourth risk control method in the hierarchy is awareness and administrative controls.

Examples of awareness and administrative controls may be written procedures, signage and training used to restrict access to hazard areas.

5. Finally, the least effective risk control method and the last choice in the hierarchy of controls to reduce risk is to protect the worker with personal protective equipment (PPE).

6.3 Hazard Categories

The SKM Power Tool software can calculate the arc-flash hazard for each bus, motor starter, disconnect, etc. The hazard will be referred to as incident energy; which can be calculated in calories per square centimeters (cal/cm2) or in joules per square centimeters (J/cm2). For the purposes of this report cal/cm2 will be used as this is the standard in the NFPA 70E.

When selecting the appropriate PPE to work on equipment, 2018 NFPA 70E, 130.5(F) allows for two separate methods: The Incident Energy Analysis Method and the Arc-Flash PPE Category Method. NFPA 70E states that “Either, but not both, methods may be used on the same piece of equipment. The results of an incident energy analysis to specify an arc-flash PPE category in Table 130.7(C)(15) shall not be permitted.” Both methods will be explained below, however this analysis calculates the incident energy and therefore the Incident Energy Analysis Method should be used to select the appropriate PPE.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -16

With the Incident Energy Analysis Method, the incident energy at each electrical device is calculated and the appropriate PPE is selected from Table 130.5(G) of NFPA 70E (2018):

Incident energy exposures equal to 1.2 cal/cm2 up to 12 cal/cm2

Arc-rated clothing with an arc rating equal to or greater than the estimated incident energy Long-sleeve shirt and pants or coverall or arc-flash suit Arc-rated face shield and arc-rated balaclava or arc-flash suit hood Arc-rated outerwear (e.g., jacket, parka, rainwear, hard hat liner) Heavy-duty leather gloves, arc-rated gloves, or rubber insulating gloves with leather protectors Hard hat Safety glasses or safety goggles Hearing protection Leather footwear

Incident energy exposures greater than 12 cal/cm2 Arc-rated clothing with an arc rating equal to or greater than the estimated incident energy Long-sleeve shirt and pants or coverall or arc-flash suit Arc-rated arc-flash suit hood Arc-rated outerwear (e.g., jacket, parka, rainwear, hard hat liner) Arc-rated gloves or rubber insulating gloves with leather protectors Hard hat Safety glasses or safety goggles Hearing protection Leather footwear

When using this table, the minimum PPE rating must exceed the maximum incident energy calculated on the report for the specific piece of equipment to be accessed; PPE may be layered if tested as a multi-layered system. All the PPE is required in the categories listed above.

With the Arc-Flash PPE Category Method, the estimated maximum available fault current, maximum fault clearing times, and minimum working distances for each electrical device is needed before determining the Arc-Flash PPE category from Table 130.7(C)(15)(a) of NFPA 70E (2018).

Once the Arc-Flash PPE category is determined, the appropriate PPE can be selected from Table 130.7(C)(15)(c) of NFPA 70E (2018), being mindful not to exceed the cal/cm2 listed in each category.

Category 1 Arc-rated clothing of at least 4 cal/cm2.

This must include arc-rated long sleeves and long pants or arc-rated coveralls. Also required is an arc-rated face shield or an arc-rated flash suit hood.

Category 2 Arc-rated clothing of at least 8 cal/cm2.

This must include arc-rated long sleeves and long pants or arc-rated coveralls. Also required is an arc-rated face shield combined with an arc-rated balaclava or an arc-rated flash suit hood.

Category 3 Arc-rated clothing that provides a minimum of 25 cal/cm2.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -17

This system of arc-rated clothing may consist of any combination of the following provided that the chosen combination has been tested and verified to provide the required level of arc-flash protection: arc-rated long sleeves, arc-rated long pants, arc-rated coveralls, arc-rated flash suit pants and arc-rated flash suit jacket. Also required is an arc-rated flash suit

Category 4 Arc-rated clothing that provides a minimum of 40 cal/cm2.

This system of arc-rated clothing may consist of any combination of the following provided that the chosen combination has been tested and verified to provide the required level of arc-flash protection: arc-rated long sleeves, arc-rated long pants, arc-rated coveralls, arc-rated flash suit pants and arc-rated flash suit jacket. Also required is an arc-rated flash suit

Each of the four arc-flash PPE categories (Arc-Flash PPE Category Method) also requires the following protective equipment: voltage-rated hardhat, safety glasses or safety goggles, ear canal insert-type hearing protection, leather footwear and leather gloves or voltage rated gloves with leather protectors. In addition, categories 3 and 4 requires that gloves be arc-rated.

The PPE categories have been streamlined in the 2018 NFPA 70E. Previous versions had an additional category. Incident energies up to 1.2 cal/cm2 were previously considered Category 0.

Category 0 was removed because the new PPE table only specifies work within the arc flash boundary.

In all cases, the arc-flash boundary, must be adhered to. Inside this boundary the appropriate PPE must be worn only to be removed after exiting the boundary. To reduce these boundaries, it may be necessary to de-energize the gear or use an approved energy reduction management system (ERMS) or reduced energy let through system (RELT). In general, this will effectively reduce the boundary and incident energy.

6.4 Labels

Arc-Flash labels have been generated and [can be found in Appendix J: Photolog/Arc-Flash Labels.

Labels will also be] [have been] applied to each switchboard, panelboard, and motor control center to provide as a minimum the following information: panel designation, nominal voltage, Arc-Flash Incident Energy, arc-flash boundary, approach boundaries, and Personal Protection Equipment (PPE) requirements. Pictures of the labels on each piece of electrical equipment can be found in Appendix J: Photolog[/Arc-Flash Labels]. The information on the labels will be used by qualified electrical workers to assess existing conditions, establish boundaries, and determine appropriate PPE to work on the equipment.

The arc-flash boundary, as defined, is the distance from the equipment at which someone could be exposed to heat equaling 1.2 cal/cm2; the amount required to cause second-degree burns. To cross this boundary, a person must use arc-rated protective equipment.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -18

There are two approach boundaries for shock protection: Limited Approach Boundary and the Restricted Approach Boundary. The Limited Approach Boundary is the shock protection boundary farthest away from exposed energized electrical conductors or circuit parts and is established to keep unqualified persons a safe distance from exposed energized parts. Unqualified workers may not cross the Limited Approach Boundary unless briefed on the hazards and continuously escorted by a qualified person. The Restricted Approach Boundary is the shock protection boundary closest to the exposed energized parts and may only be crossed by qualified electrical workers following safe electrical work-practices which include wearing appropriate shock protection and using insulated tools.

Arc-flash labels were based on existing conditions and settings, as it is recognized that recommendations in this report may not be implemented immediately in full. It should be noted that modification of equipment, changes to the system configuration, adjustment of protective device settings, or failure to properly maintain equipment may invalidate these results and labels will need to be updated.

6.5 Arc-Flash Hazard Analysis – Results and Recommendations

The results of the arc-flash hazard analysis as presented in this report are based on the IEEE 1584 calculation procedures and assume that protective devices considered are in working order and will operate within their specified tolerances to clear faults from the system.

The full results can be found at the end of this report in Appendix H, and Appendix I, where each electrical bus (panel, switchboard, motor control center, transfer switch, etc.) is identified with corresponding voltage, working distance, fault current, incident energy, arc-flash boundary, and PPE requirements.

The values shown in the arc-flash hazard analysis assume that the fault is cleared by the upstream protective device; even if the equipment contains a main overcurrent protective device. This assumption is intended to produce conservative results and therefore cover the case where faults originating in such equipment may propagate to the line side of the local main breaker. The calculations are cut off at a maximum arcing duration of 2.0 seconds.

A conservative fault current value may not reveal the worst-case Arc-Flash incident energy values that may be present. Lower fault currents sometimes result in higher arc-flash energies because a protective device may take longer to operate and extinguish the arc.

For reference, an incident energy value of 1.2 cal/cm2 is considered the threshold of second-degree burns; while incident energy values of approximately 8-12 cal/cm2 are commonly considered the boundary line between “low” and “high” PPE levels, and an incident energy level of 40 cal/cm2 is considered as “maximum allowable”.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -19

While NFPA 70E does not explicitly prohibit work at locations with energy levels above 40 cal/cm2, research into the potential for non-burn injuries (internal injuries, hearing damage, etc.)

indicates that these other injuries become a significant concern at such high-energy locations. NFPA 70E does not define protective clothing classes with arc-ratings above 40 cal/cm2 and many employers have used this level as a threshold above which no energized work is allowed under any conditions due to the increased risk of non-burn injuries (hearing damage, etc.)

Achieving lower arc-flash incident energy levels requires faster tripping of the overcurrent protective devices. This is somewhat contrary to the goal of selective coordination where the upstream overcurrent protective devices are intentionally adjusted to hold for longer trip times to allow for the downstream devices nearest a fault to open and isolate the fault while keeping the remaining system in operation. As such, a compromise must be made between selective coordination or expensive mitigation systems.

We analyzed the system under existing conditions and found that all of the electrical devices’ incident energy levels were just above the second-degree burn threshold (1.2 cal/cm2). Thus, requiring the lowest level of PPE if worked on while energized. We do not offer any recommendations to lowering the arc-flash incident levels. Qualified and trained electrical workers will need to select appropriate PPE when working on this equipment.

Electrical work must only be accomplished by qualified electrical workers. Protection from arc-flash hazards can best be provided by working only on circuits or equipment that have been placed in an electrically safe work condition. This could mean eliminating the potential electrical hazard completely by deenergizing the entire system.

For Arc-Flash results, corresponding to existing devices and settings connected to normal utility power, see Appendix H: Arc-Flash Results – Existing Settings.

For Arc-Flash results, corresponding to recommended devices and settings connected to normal utility power, see Appendix I: Arc-Flash Results – Recommended Settings.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -20

7. Non-Destructive Inspection

7.1 General

Routine inspection and maintenance of electrical systems is recommended by electrical equipment manufacturers and NFPA safety codes. Specific intervals of inspection and maintenance could vary anywhere from a few months to a few years and is dependent on the equipment’s age, condition, use, loading, environment it is installed in, etc. Typical industry recommendations include inspect-ing electrical equipment each year or after any severe short circuit. Inspection and maintenance help to identify impending equipment failure and safety hazards, as well as preventing of equipment damage and personnel injury. Inspection and maintenance should be conducted on a regularly scheduled basis, by qualified personnel properly trained and certified.

NPC Energy Services inspected all electrical panels to determine if any system overloads, loose de-fective components, loose or defective connections or splices, damaged equipment or materials, hot spots or places of excess heat, current carrying conductor anomalies that may cause failures, shock hazards, and/or other electrical safety issues exist in the facility. The inspections were done with the equipment energized and under normal operating loads and conditions.

In addition to visual observations, commercially accepted methods and equipment were used to per-form the inspections. Infrared scanning was done to detect the presence of heat at connection points, breakers, fuses, conductors, etc.; ultrasonic testing was performed to detect high frequency noise emitting from any electrical components that are failing; various measurements were made to con-firm that the voltage, amperage, and harmonic levels are within the intended operating range; me-chanical connections were checked, tightened and torqued where it could be done safely; minor code and safety violations, such as loose connections and missing breaker blanks were corrected.

7.2 Circuit Tracing

The National Electrical Code requires that all circuits be legibly identified as to its clear, evident, and specific purpose or use.

The accuracy of existing panel schedules is often questioned, due to the age and number of changes that typically occur in facilities over time.

All reasonable efforts were made to identify the loads connected to every circuit in each panel, us-ing commercially available equipment to trace each circuit in the facility.

Updated panel directories [will be] [have been] applied to each panel. Panel directories have also been included in Appendix L: Panel Schedules.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Page -21

7.3 Cable protection

The National Electrical Code (NEC), Article 240 requires that conductors be protected against overcurrent in accordance with their ampacities specified in NEC 310.15. Feeder overcurrent protective devices were reviewed to verify that the load side conductors are protected in accordance with NEC Articles 240 and 310. The analysis does not consider adjustment factors such as for voltage drop or conduit fill.

Conductors appeared to be adequately protected as required by the NEC, however we noted that the ampacity rating of the conductors in the exterior weatherhead riser are rated less than the ampacity rating of the protecting circuit breaker in Panel CS. In this particular case, it would be a concern if the load exceeds the rating of the conductor but not the overcurrent protective device rating. The NEC has a provision that allows for the next higher standard overcurrent device rating to be used (above the ampacity for the conductors being protected) where a set of conditions are met. One of the conditions is that the ampacity of the conductors does not correspond with the standard ampere rating of a fuse or circuit breaker.

7.4 System Deficiencies

As part of the site survey and non-destructive inspection of electrical systems at Building 2228, we noticed the following issues, code violations, and concerns:

1. The electrical distribution system does not have any connections to a grounding electrode system. We recommend that a grounding electrode system be installed consisting of new ground rods and connections to existing electrodes (building steel, metallic water piping, concrete footer) where present, with a new copper grounding electrode conductor terminated at the electrode system and service ground bar.

2. Panel CS (9800) does not have a ground bar for termination of the equipment grounding conductors. Existing equipment grounding conductors are terminated under panel mounting screws. We recommend that a ground bar be installed in the electrical panel and re-terminating the equipment grounding conductors to the ground bar.

For adverse findings associated with the non-destructive testing, see Appendix K: Non-Destructive Inspection.

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix A

Electrical Distribution System Riser Diagram

Existing Configuration

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix B

Short Circuit Input Data

DAPPER Fault Analysis Input Report (English)

Project: 2228 Base Project

Utilities

Contribution From Name

Bus Name

In/Out Service

Nominal Voltage

-------- Contribution Data -------- PU (100 MVA Base

X PUR PUX/RUnitsDuty

UTILITY TPRIMARY 12,470 Amps 4.67In 5,601

SLG:

3P:

Amps 4.56 0.9740.222

Pos:

Zero:5,238

0.173 0.808

Cables

Cable Name

From Bus To Bus

Qty /Ph

Length Feet

------ Cable Description ------

Size Cond. Type Duct Type Insul

Per Unit (100 MVA Base)

R pu jX pu

In/Out Service

WEATHERHEAD

PNL CS

1 15 6 Pos:

Zero:

12.7604 1.6667

4.2396

CBL PNL CS In

20.2865

MagneticCopper

TSECONDARY

WEATHERHEA

1 75 2 XLPE Pos:

Zero:

41.0807 4.0755

10.1172

CBL SERVICE DRO In

88.1771

Non-MagneticAluminum

2-Winding Transformers

Xformer Name Bus Conn. Volts FLA

Nominal kVA

Z PU (100 MVA Base)

R pu jX pu

In/Out Service

------------------Primary & Secondary---------------

TUTILITY TPRIMARY D 12,470 5

TSECONDARY D 240 241

15.0 Pos:

Zero:

23.3533

23.3533

57.6733

57.6733

In

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix C

Short Circuit Analysis

Riser Diagram

TPRIMARY

Nominal 12470.0 V

UB LL 4850.6 A

UB SLG 5238.0 A

S

P TUTILITY

Nominal 12470.0 V Nominal kVA 15 kVA Z% 2.8000 % X/R 2.4696

PNL CS

Nominal 240.0 V

UB LL 1617.4 A

UB SLG 1813.8 A

CBL SERVICE DROP

Size 2 AWG Qty/Phase 1 Insulation XLPE Class XHHW-2 Raceway Non-Magnetic Length 75.0 ft

TSECONDARY

Nominal 240.0 V

UB LL 2212.7 A

UB SLG 3584.8 A

UTILITY

CB PNL CS

Trip 60.0 A Plug 60.0 A

CBL PNL CS

Size 6 AWG Qty/Phase 1 Insulation Class XHHW Raceway Magnetic Length 15.0 ft

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix D

Overcurrent Device Coordination Analysis

Existing Settings

0.5 1 10 1

K

K

0.01

0.10

CURRENT IN AMPERES

T I M E

I N

S E C O N D S

SQUARE D

QO, 2-Pole

QO

Trip 60.0 A Plug 60.0 A Settings Phase Fixed (730-6, 60A)

CB PNL CS

SQUARE D

QO, 1-Pole

QO

Trip 20.0 A Plug 20.0 A Settings Phase Fixed (730-3)

CB BRANCH CIRCUITS

SQUARE D

QO, 2-Pole

QO

Trip 20.0 A Plug 20.0 A Settings Phase Fixed (730-4, 20A)

CB BRANCH 2 POLE

SQUARE D

QO, 2-Pole

QO

Trip 60.0 A Plug 60.0 A Settings Phase Fixed (730-6, 60A)

CB PNL CS

SQUARE D

QO, 1-Pole

QO

Trip 20.0 A Plug 20.0 A Settings Phase Fixed (730-3)

CB BRANCH CIRCUITS

SQUARE D

QO, 2-Pole

QO

Trip 20.0 A Plug 20.0 A Settings Phase Fixed (730-4, 20A)

CB BRANCH 2 POLE

TPRIMARY

S

P TUTILITY

PNL CS

CBL SERVICE DROP

TSECONDARY

UTILITY

CB PNL CS

CBL PNL CS

TCC: 2228 PNL CS AS-IS Current Scale x 1 Reference Voltage: 240 2019

Nov 04, 2019 10:12:46 Page 1 Project Name: 2228 TCC Name: 2228 PNL CS AS-IS.tcc Reference Voltage: 240 V Current Scale: X 10^0 TCC Notes:

TCC Comment:

Fault Duty Option: Study Result - Bus Fault Current

ALL INFORMATION PRESENTED IS FOR REVIEW, APPROVAL, INTERPRETATION,

AND APPLICATION BY A REGISTERED ENGINEER ONLY.

SKM DISCLAIMS ANY RESPONSIBILITY AND LIABILITY RESULTING

FROM THE USE AND INTERPRETATION OF THIS SOFTWARE.

CAPTOR (Computer Aided Plotting for Time Overcurrent Reporting)

COPYRIGHT SKM SYSTEMS ANALYSIS, INC. 1983-2019

Device Name: CB PNL CS TCC Name: 2228 PNL CS AS-IS.tcc Bus Name: PNL CS Bus Voltage: 240.0V Function Name: Phase Manufacturer: SQUARE D Description: 15-125A Type: QO, 2-Pole AIC Rating: 10kA Fault Duty: 1813.8A Frame: QO 240V 60A Tcc Current Multiplier: 1 Tcc Time Multiplier: 1 Tcc Time Adder: 0 Trip: 60A Setting: 1) Fixed (730-6, 60A)

Device Name: CB BRANCH CIRCUITS TCC Name: 2228 PNL CS AS-IS.tcc Bus Name: PNL CS Bus Voltage: 240.0V Function Name: Phase Manufacturer: SQUARE D Description: 15-70A Type: QO, 1-Pole AIC Rating: 10kA Fault Duty: 1813.8A Frame: QO 240V 20A Tcc Current Multiplier: 1 Tcc Time Multiplier: 1 Tcc Time Adder: 0 Trip: 20A Setting: 1) Fixed (730-3)

Device Name: CB BRANCH 2 POLE TCC Name: 2228 PNL CS AS-IS.tcc Bus Name: PNL CS Bus Voltage: 240.0V Function Name: Phase Manufacturer: SQUARE D Description: 15-125A Type: QO, 2-Pole AIC Rating: 10kA Fault Duty: 1813.8A Frame: QO 240V 20A Tcc Current Multiplier: 1 Tcc Time Multiplier: 1 Tcc Time Adder: 0 Trip: 20A Setting: 1) Fixed (730-4, 20A)

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix E

Overcurrent Device Coordination Analysis

Recommended Settings

(No Recommendations)

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix F

Overcurrent Protection Device

Base Project

LOW VOLTAGE THERMAL MAGNETIC MOLDED CASE BREAKERS SETTINGS

DESIGNATION TRIP UNITFRAME

TYPE/MODELDescriptionMFRLocation/Name Amps

Frame

TYPE

MODEL

Amps

Sensor/Plug LT SETTING INST SETTING

Fixed (730-4, 20A) QO 2020 SQUARE D QO, 2-Pole15-125A20PNL CS

CB BRANCH 2 POLE

Fixed (730-3) QO 2020 SQUARE D QO, 1-Pole15-70A20PNL CS

CB BRANCH CIRCUITS

Fixed (730-6, 60A) QO 6060 SQUARE D QO, 2-Pole15-125A60PNL CS

CB PNL CS

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix G

Overcurrent Protection Device

2204, 2212, & 2218 Tasks 1, 2, 3, 4, & 5

Appendix H

Arc-Flash Results

Arc Flash Evaluation Report

Base Project

Working Distance

(in)

Equip Type

Breaker Opening

Time (sec.)

Trip/ Delay Time (sec.)

Protective Device Name

Incident Energy

(cal/cm2)

ArcFlash Boundary

(in)

Bus Name Bus Bolted Fault (kA)

Bus Arcing…