Brady Safety Client User Manual

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

Brady Safety Client 1

Arc Flash Risk Assessment Report

* This is a sample report

Prepared for: Brady Safety Client 1 Date: January 1, 2021

Project # ABCD12345

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

January 26, 2021

Brady Safety Client 1

Attention: Name Address Email Phone

Dear Brady Safety Client 1,

We are pleased to provide the following Brady Safety Software and Services “Arc Flash Risk Assessment Report” for the Brady Safety Client 1 location. An arc risk assessment is a very important step to help

ensure a safe and compliant workplace. We commend you on your decision to take this step, and are honored to be your trusted advisor and partner. We look forward to working with you to help improve your level of compliance and create a safer workplace environment for your employees.

Brady Safety conducted the on-site data gathering portion of your assessment on December 14 through December 16, 2021. Once the data was compiled and reviewed, a software model of your electrical system was created and various electrical engineering calculations were performed. The following report includes the findings of the assessment, as well as recommendations to help you achieve your compliance goals.

It was our pleasure being of service to you and we look forward to helping you with any future needs. Please do not hesitate to contact me if you have any questions or concerns regarding the work done onsite or any of the data presented in this report.

Sincerely,

*Brady Electrical Engineer

Safety Software & Services Brady Corporation

safetyservices@bradycorp.com

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

Table of Contents

1. Introduction



General Discussion.................................................................................................................... 5



Facility and Electrical System Description ................................................................................. 6

2. Executive Summary



Scope of Work ........................................................................................................................... 7



Fault Current Study.................................................................................................................... 7



Equipment Evaluation ................................................................................................................ 7



Coordination Study .................................................................................................................... 7



Arc Flash Study ......................................................................................................................... 8

3. Fault Current Study



Fault Current Study Procedure .................................................................................................. 9



Fault Current Study Calculation Data and Assumptions ........................................................... 9



Fault Current Study Results .................................................................................................... 10



Fault Current Study Recommendations .................................................................................. 10

4. Equipment Evaluation



Protective Device Evaluation ................................................................................................... 11



Protective Device Recommendations ...................................................................................... 12

5. Coordination Study



Coordination Study Procedure ................................................................................................ 13



Coordination Study Assumptions ............................................................................................ 13



Coordination Study Results ..................................................................................................... 14



Coordination Study Recommendations ................................................................................... 14

6. Arc Flash Risk Assessment



Arc Flash Risk Assessment Procedure ................................................................................... 15



Arc Flash Risk Assessment Assumptions ............................................................................... 15



Arc Flash Labels and NFPA 70E Requirements ..................................................................... 15



Arc Flash Risk Assessment Results ........................................................................................ 16



Arc Flash Risk Assessment Recommendations ...................................................................... 17

7. Additional Recommendations



NEC Compliance Issues .......................................................................................................... 18



General Observations .............................................................................................................. 18

Appendix A



Fault Current Study Details

Appendix B



Equipment Evaluation Details

Appendix C



Time-Current Curve (TCC) Plots

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

Appendix D



Arc Flash Risk Assessment Details

Appendix E



System Input Data

Appendix F



Brady Single Line Diagram Drawing No. SVCF123456-01

Appendix G



Utility Information

Appendix H



Sample Energized Electrical Work Permit

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

SECTION 1: INTRODUCTION

General Discussion:

The Occupational Safety and Health Administration (OSHA) requires that employers provide a workplace for their employees that is free from recognized hazards that may cause death or serious injury. An arc flash risk assessment is a key part of what OSHA requires as it relates to electrical hazards, and allows employers to identify the potential arc flash risks and what kind of personal protective equipment (PPE) is needed to keep employees safe from the heat, light and blast associated with an arc fault incident.

OSHA standard 1910 Subpart S deals with electrical safety related work practices. OSHA 1910.132(d)

requires that “The employer shall assess the workplace to determine if hazards are present, or are likely

to be present, which necessitate the use of personal protective equipment (PPE). If such hazards are present, or likely to be present, the employer shall: select, and have each affected employee use, the types of PPE that will protect the affected employee from the hazards identified in the hazard assessment; communicate selection decisions to each affected employee; and, select PPE that properly

fits each affected employee.” Furthermore, “The employer shall verify that the required workplace hazard

assessment has been performed through a written certification that identifies the workplace evaluated; the person certifying that the evaluation has been performed; the date(s) of the hazard assessment; and,

which identifies the document as a certification of hazard assessment.” To reiterate the requirement,

OSHA 1910.335(a)(1)(i) requires that “Employees working in areas where there are potential electrical

hazards shall be provided with, and shall use, electrical protective equipment that is appropriate for the

specific parts of the body to be protected and for the work to be performed.”

While OSHA makes it clear that employees need to be made aware of and protected from electrical risks, OSHA relies on the National Fire Protection Association (NFPA) standard 70E (Standard for Electrical Safety in the Workplace) for specific requirements as to how this should be done. NFPA 70E was developed by the NFPA to help employers meet the OSHA requirements. The OSHA documents are written in general terms that outline what shall be done; whereas NFPA 70E gives detailed information about how to achieve OSHA compliance by providing a safe workplace.

According to NFPA 70E 130.5, “An arc flash risk assessment shall be performed and shall determine if an

arc flash hazard exists. If an arc flash hazard exists, the risk assessment shall determine appropriate safety-related work practices, the arc flash boundary and the PPE to be used within the arc flash

boundary.” NFPA 70E then goes into great detail regarding the specifics of the arc flash assessment.

The requirements presented by OSHA and NFPA 70E are the driving force behind the arc flash assessment that Brady conducted at the Brady Safety Client 1 facility (BSC1).

Looking ahead, it is prudent to understand that over the course of time, buildings change and equipment may be added, removed or modified. Any change to an overcurrent protective device, conductor length or equipment location could invalidate some of the calculations performed as part of your arc flash risk assessment, leaving you and your employees vulnerable to an unsafe work condition. Performing a periodic review, or audit, helps to identify any potential gaps and allows you to ensure that you have a

safe and compliant workplace. According to NFPA 70E 130.5, “An arc flash risk assessment…shall be

updated when a major modification or renovation takes place. It shall be reviewed periodically, at intervals not to exceed 5 years, to account for changes in the electrical distribution system that could affect the

results of the arc flash risk assessment.” When changes are made, or the 5 year mark approaches, Brady

is available to offer continued support in order to facilitate ongoing compliance.

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

Facility and Electrical System Description:

The BSC1 facility being studied has an area of approximately 99,999 square feet. The facility primarily consists of offices, conference rooms, training rooms and other training and shop spaces. Power for the building is provided from the utility via a closed delta overhead transformer bank consisting of three transformers with a primary voltage of 12.47kV and a secondary voltage of 480Y/277. The building service disconnect contains 1500 amp fuses and feeds a main gutter in the electrical room. From this gutter, power is distributed throughout the facility by branch panelboards, transformer and disconnects. Refer to Appendix F for the single-line diagram produced by Brady (General Drawing).

Based on the information provided by the utility company, the available fault current at the secondary of the utility transformer using an infinite bus calculation is 21,999 amps. This information can be found in the utility letter in Appendix G.

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BRADY SAFETY SOFTWARE & SERVICES REPORT – Arc Flash Risk Assessment

SECTION 2: EXECUTIVE SUMMARY

Scope of Work:

The power system study for the BSC1 facility consisted of a fault current study, an equipment evaluation, a protective device coordination study with associated suggested device settings (if applicable), an arc flash study, and any comments and recommendations where necessary. The BSC1 facility does not have an emergency system or any switching schemes in the electrical distribution system; therefore one mode of operation was studied.

Using SKM Power*Tools Electrical Engineering Software Version 9.0.05 (SKM), a computer model of the BSC1 electrical distribution system was created based on the information gathered in the field by Brady. This model was then used to study the electrical system and run various calculations. The results of the calculations are contained in this report. The electrical system input data used for the calculations can be found in Appendix E.

Fault Current Study:

Fault current studies (also known as short-circuit current studies) are performed to determine the

maximum current that could flow through an electrical distribution system after a “fault” or abnormal

condition occurs. This study must be done to ensure that the electrical equipment specified (i.e. panels, disconnect switches, etc.) has adequate bus withstand ratings and that overcurrent protective devices have adequate interrupting duties.

The SKM “Dapper” module was used by Brady to calculate the available three-phase, RMS symmetrical, short circuit amperes at each piece of equipment in the system.

Equipment Evaluation:

The fault current calculations described in the previous section were used to evaluate the protective

devices connected to each bus. In this evaluation, the SKM “Equipment Evaluation” module uses the

voltage rating and interrupting rating of each protective device and compares them to the results of the fault current study. The results will show a status of Pass, Fail or Marginal.

Coordination Study:

Coordination studies are performed to limit the extent and duration of electrical service interruption when there are equipment failures, human error or other events that cause outages in any portion of the electrical system, or the electrical system overall. A properly coordinated system can also help prevent injury to personnel and limit damage to equipment or system components. Through a coordination study, devices are carefully selected and adjusted to trip in a specific sequence, preferably beginning and ending with the device closest to the fault.

The coordination study was done using the SKM “Captor” module. Overcurrent protective devices are

depicted on log-log graphs that use time on the horizontal axis and current on the vertical axis. Coordination discrepancies are best shown graphically on these time-current curve (TCC) plots where

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