26_05_73.13_08_ARC_FLASH_HAZARD_ANALYSIS.pdf

FY14 Mac Lock Modernization - Amendment 0002 FY14MCLMPC1

SECTION TABLE OF CONTENTS

DIVISION 26 - ELECTRICAL

SECTION 26 05 73.13 08

ARC FLASH HAZARD ANALYSIS

PART 1 GENERAL

1.1 REFERENCES

1.2 SYSTEM DESCRIPTION

1.3 SUBMITTALS

1.4 QUALIFICATIONS

1.5 COMPUTER ANALYSIS SOFTWARE

PART 2 PRODUCTS

2.1 STUDY

2.2 DATA COLLECTION

2.3 ARC FLASH HAZARD ANALYSIS

2.4 REPORT SECTIONS

PART 3 EXECUTION

3.1 ARC FLASH WARNING LABELS

3.2 ARC FLASH ANALYSIS REPORT

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SECTION 26 05 73.13 08

ARC FLASH HAZARD ANALYSIS

PART 1 GENERAL

1.1 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA 70E (2012; Errata 2012) Standard for Electrical Safety in the Workplace

UNDERWRITERS LABORATORIES (UL)

UL 969 (1995; Reprint Nov 2008) Standard for Marking and Labeling Systems

1.2 SYSTEM DESCRIPTION

The Contractor shall perform and furnish an Arc Flash Hazard Analysis Study per NFPA 70E, reference Article 130.5 and Annex D.

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-06 Test Reports

Arc Flash Analysis Report; G AOF

The results of the arc flash hazard analysis studies shall be submitted in a final report. No more than five bound copies of the complete final report shall be submitted.

The Contractor shall also provide all native project data base study files to the Government in electronic format. Studies shall be conducted using the software specified in paragraph COMPUTER

ANALYSIS SOFTWARE

1.4 QUALIFICATIONS

The arc flash hazard analysis studies shall be conducted by a licensed electrical engineer skilled in performing and interpreting the power system studies. This person shall be a full-time employee of the Engineering Services Organization and shall have a minimum of 5 years of experience in performing power systems studies. Engineering services organization shall demonstrate experience in Arc Flash Hazard Analysis by submitting names of

SECTION 26 05 73.13 08 Page 2 at least ten actual arc flash hazard analyses it has performed in the last 2 years.

1.5 COMPUTER ANALYSIS SOFTWARE

The study shall be performed using the latest revision of the SKM Systems Analysis Power Tools for Windows (PTW) software program.

PART 2 PRODUCTS

2.1 STUDY

The Contractor shall furnish an Arc Flash Hazard Analysis Study per NFPA 70E, reference Article 130.5 and Annex D

2.2 DATA COLLECTION

The Contractor shall collect all field data as required by the power system studies to ensure accurate equipment modeling. The individual(s) collecting the field data shall be qualified as defined by NFPA 70E.

Data collection shall begin downstream from the primary of the new 500 KVA transformers and continue down through the project electrical distribution system. The available short circuit current at the primary of the new 500 KVA transformers will be provided by the Government

Include fault contribution of motors in the study.

2.3 ARC FLASH HAZARD ANALYSIS

a. The arc flash hazard analysis shall be performed according to the IEEE 1584 equations that are presented in NFPA 70E, Annex D. The arc flash hazard analysis shall be performed in conjunction with the short-circuit analysis and the protective device time-current coordination analysis in Section 26 28 01.00 10 COORDINATED POWER

SYSTEM PROTECTION.

b. The flash protection boundary and the incident energy shall be calculated at all significant locations in the electrical distribution system such as switchboards, switchgear, motor-control centers, panelboards, industrial control panels, motor control panels, etc., where work could be performed on energized parts.

c. The Arc-Flash Hazard Analysis shall include all equipment locations operating at 50 volts and higher that may be inspected, modified, serviced or maintained while energized.

d. Safe working distances shall be specified for calculated fault locations based upon the calculated arc flash boundary considering an incident energy of 1.2 cal/cm2.

e. The short circuit calculations and the corresponding incident energy calculations for multiple system scenarios must be compared and the greatest incident energy must be uniquely reported for each equipment location. The Arc Flash Hazard analysis shall include calculations for maximum and minimum contributions of fault current magnitude for normal and emergency operating conditions. The minimum calculation shall assume that the utility contribution is at a minimum and shall assume a minimum or no motor load. Conversely, the maximum

SECTION 26 05 73.13 08 Page 3 calculation shall assume a maximum contribution from the utility and shall assume motors to be operating. Facility operational conditions shall be considered. Fault contributions from induction motors should not be considered beyond 5 cycles.

f. For each equipment location with a separately enclosed main device (where there is adequate separation between the line side terminals of the main protective device and the work location), calculations for incident energy and flash protection boundary shall include both the line and load side of the main breaker.

g. When performing incident energy calculation on the line side of the main breaker, the line side and load side contributions must be included in the fault calculation.

h. Mis-coordination should be checked amongst all devices within the branch containing the immediate protective device upstream of the calculation location and the calculation should utilize the fastest device to compute the incident energy for the corresponding location.

i. Arc Flash calculations shall be based on actual overcurrent protective device clearing time. Maximum clearing time will be capped at 2 seconds based on IEEE 1584.

j. Provide the following:

1. Results of the Arc-Flash Hazard Analysis shall be submitted in tabular form, and shall include device or bus name, bolted fault and arcing fault current levels, flash protection boundary distances, working distances, personal-protective equipment classes and AFIE (Arc Flash Incident Energy) levels.

2. The Arc-Flash Hazard Analysis shall report incident energy values based on recommended device settings for equipment within the scope of the study.

3. The Arc-Flash Hazard Analysis may include recommendations to reduce AFIE levels and enhance worker safety.

2.4 REPORT SECTIONS

a. Input Data shall include but not be limited to the following:

1. Utility three-phase and line-to-ground available contribution with associated X/R ratios

2. Motor contribution data

3. Feeder type, construction, size, # per phase, length, impedance and conduit type

4. Generation contribution data (utility and generator) including short circuit reactance, rated KVA, rated voltage, three-phase and single line-ground contribution for utility source and X/R ratio.

5. Transformer primary & secondary voltages, winding configurations, kVA rating, impedance, and X/R ratio

6. Reactor data, including voltage rating and impedance

b. Incident energy and flash protection boundary calculations.

1. Arcing fault magnitude

2. Device clearing time

3. Duration of arc

4. Arc flash boundary

SECTION 26 05 73.13 08 Page 4

5. Working distance

6. Incident energy

7. Hazard Risk Category

8. Recommendations for arc flash energy reduction

PART 3 EXECUTION

3.1 ARC FLASH WARNING LABELS

The Contractor shall provide a color 4 in. x 5 in. thermal transfer type label of high adhesion polyester for each work location analyzed. Labels shall be designed in accordance with NEMA Z535.4, UL 969, and NFPA 70. All labels shall be based on recommended overcurrent device settings and will be provided after the results of the analysis have been submitted to the Government and after any system changes or adjustments have been incorporated. The label shall have an orange header with the wording, "WARNING, ARC FLASH HAZARD", and shall include the following information:

1. Location designation

2. Nominal system voltage

3. Flash protection boundary

4. Hazard risk category

5. Incident energy

6. Working distance

7. Study report number and issue date

Labels shall be machine printed, with no field markings.

Arc flash labels shall be provided in the following manner and all labels shall be based on recommended overcurrent device settings.

1. For each 600, 480 and applicable 208 volt panelboards and disconnects, one arc flash label shall be provided

2. For each motor control center, one arc flash label shall be provided

3. For each low voltage switchboard, one arc flash label shall be provided

4. For each switchgear, one flash label shall be provided

5. For each motor control panel, starter panel, control panel, one arc flash label shall be provided.

Labels shall be field installed by the Contractor.

3.2 ARC FLASH ANALYSIS REPORT

The report shall include, but not be limited to, the following:

1. Executive Summary including Introduction, Scope of Work and Results/Recommendations.

2. Arc Flash Hazard Methodology Analysis Results and recommendations including details of the incident energy and flash protection boundary calculations, along with arc flash boundary distances, working distances, incident energy levels and personal protection equipment levels

3. Arc Flash Labeling section showing types of labels to be provided

4. Comments and recommendations for system improvements, where needed

5. One-Line system diagram that shall be computer generated and will clearly identify individual equipment buses, bus numbers used in the short circuit analysis, cable and bus connections between the equipment, calculated maximum short circuit current at each bus

SECTION 26 05 73.13 08 Page 5 location, device numbers used in the time-coordination analysis, and other information pertinent to the computer analysis.

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