Electrical Safety ARC FLASH ANALYSIS Electrical ARC Safety

Electrical Safety ARC FLASH ANALYSIS

Electrical ARC Safety FLASH ANALYSIS

ARC-FLASH Electrical Safety • As much as 80% of all electrical injuries are burns resulting from an arc-flash and ignition of flammable clothing. • Arc temperature can reach 35, 000°F - this is four times hotter than the surface of the sun Fatal burns can occur at distances over 10 ft.

ARC EXPOSURE ENERGY BASICS Electrical Safety • Exposure Energy is Expressed in cal/cm 2 • 1 cal/cm 2 Equals the Exposure on the tip of a finger by a Cigarette Lighter in One Second • An Exposure Energy of Only One or Two cal/cm 2 Will Cause a 2 nd Degree Burn on Human Skin

Industry Standards and Regulations Electrical Safety • OSHA 29 CFR 1910 Subpart S • OSHA Enforces NEC 2002 110. 16 & NFPA 70 E • NFPA 70 E-2000 • Requirements for shock and arc flash boundaries • Requirements for personal protective equipment • NEC 110. 16 -2002

NEC 2002 110. 16 Flash Safety Protection. Electrical Switchboards, panel boards, industrial control panels, and motor control centers in other than dwelling occupancies, that are likely to require examination, adjustment, servicing, or maintenance while energized, shall be field marked to warn qualified persons of potential electric arc flash hazards. The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment. FPN No. 1: NFPA 70 E-2000, Electrical Safety Requirements for Employee Workplaces, provides assistance in determining severity of potential exposure, planning safe work practices, and selecting personal protective equipment. FPN No. 2: ANSI Z 535. 4 -1998, Product Safety Signs and Labels, provides guidelines for the design of safety signs and labels for application to products.

Sample NEC Warning Article 110. 16 Electrical Safety WARNING ! Arc Flash and Shock Hazard Appropriate PPE Required

ARC Flash Analysis Electrical Safety • OSHA 1910. 132(d) Where work will be performed within the flash protection boundary, the flash hazard analysis shall determine, and the employer shall document, the incident energy exposure to the worker (in cal/cm 2) • OSHA 1910. 269(I)(6) Flame resistant (FR) clothing and PPE shall be used by the employee based upon the incident energy exposure associated with the specific task. • As an alternative, PPE requirements of NFPA 70 E Part II 3 -3. 9 may be used in lieu of a detailed flash hazard analysis.

Sample NEC Warning Article 110. 16 Electrical Safety

Electrical Safety

Approach Boundaries Electrical Safety Nominal System Voltage Range Limited Approach Boundary Restricted Approach Boundary Prohibited Approach Boundary Phase-to-Phase Exposed Moveable Conductor Exposed Fixed Circuit Part Includes Inadvertent Movement Adder 0 - 50 Not specified 51 - 300 10 ft. 0 in. 3 ft. 6 in. Avoid contact 301 - 750 10 ft. 0 in. 3 ft. 6 in. 1 ft. 0 in. 0 ft. 1 in. 751 V - 15 k. V 10 ft. 0 in. 5 ft. 0 in. 2 ft. 2 in. 0 ft. 7 in. 15. 1 – 36 k. V 10 ft. 0 in. 6 ft. 0 in. 2 ft. 7 in. 0 ft. 10 in. 36. 1 – 46 k. V 10 ft. 0 in. 8 ft. 0 in. 2 ft. 10 in. 1 ft. 5 in. 46. 1 – 72. 5 k. V 10 ft. 0 in. 8 ft. 0 in. 3 ft. 3 in. 2 ft. 1 in. 72. 6 – 121 k. V 10 ft. 8 in. 8 ft. 0 in. 3 ft. 3 in. 2 ft. 8 in. 138 – 145 k. V 11 ft. 0 in. 10 ft. 0 in. 3 ft. 7 in. 3 ft. 1 in.

NFPA 70 E provides two choices for PPE selection: Electrical Safety • Do an arc flash hazard analysis, and document the incident energy exposure – IEEE 1584 – SKM (Arc Flash Evaluation Module) – Arc. Pro Software – Duke Power Cal/Flux Software • As an alternate, use the “Hazard Risk Category Classifications” table to choose the PPE level required for the task

Hazard Risk Category Tables Electrical Safety

Hazard Risk Category Classification Electrical Safety • NFPA 70 E – Hazard Risk 0 – This hazard risk category poses minimal risk. • NFPA 70 E – Hazard Risk 1 – This hazard risk category poses some risk. • NFPA 70 E – Hazard Risk 2 – This hazard risk category involves tasks that pose a moderate risk. • NFPA 70 E – Hazard Risk 3 – This hazard risk category involves tasks that pose a high risk. • NFPA 70 E – Hazard Risk 4 – This hazard risk category represents tasks that pose the greatest risk.

Methods of Reducing Hazard Risk Electrical Safety • Specifying Current Limiting Fuses on Low Voltage Switchgear Breakers • Specifying ARC Resistance Medium Voltage Switchgear • Remote Control of Switchgear Breakers • High Resistance Grounding on Low Voltage and Medium Voltage (15 k. V and below) Systems

What We Offer Our Clients Electrical Safety • Design of safer power systems while insuring compliance with OSHA NFPA 70 E standards and IEEE 1584 • Save time with the fully integrated Short Circuit, Time Current Coordination, Equipment Evaluation and Arc Flash Evaluation • Offer alternatives to reduce exposure to ARC Flash Energy.