Arc Flash NFPA 70E 3

Summary

The video script discusses the importance of proper Personal Protective Equipment (PPE) in preventing injuries from arc flashes and electrical hazards. It highlights the flammability and melting risks of various fabrics, emphasizing the need for non-melting materials in undergarments. The script also covers the use of arc-rated balaclavas, the placement of barriers and barricades, and the role of attendants in safety. It underscores the significance of incident energy in selecting PPE and the necessity for a qualified person to have the right skills and knowledge for electrical work safety.

Takeaways

• 🔥 Many fabrics, including cotton, polyester, and blends, are flammable and can continue to burn, posing a risk of serious injuries.
• 🌡 Synthetic materials like nylon, polyester, polypropylene, and spandex can melt during an arc flash, potentially aggravating burn injuries.
• 👚 Properly rated Personal Protective Equipment (PPE) is essential to limit the thermal energy exposure to a safe level, but it may not prevent undergarments from melting onto the skin.
• 🧥 Undergarments must be made of non-melting material to avoid additional injury from melted fabrics.
• 🎭 Arc-rated balaclavas, such as balaclava sock hoods, are designed to protect the neck and head, excluding the face, and should fit tightly with minimal air pockets.
• ⚠️ A barricade is a physical obstruction intended to provide a warning and limit access to hazardous areas, and it should be installed according to specific safety guidelines.
• 🚷 The placement of barriers and barricades is crucial for safety and is often the duty of workers performing tasks in proximity to electrical hazards.
• 👷‍♂️ Attendants are responsible for manual signaling and alerting to keep unqualified employees away from areas with electrical hazards.
• 🔢 Incident energy, measured in calories per square centimeter, is a critical factor in selecting appropriate PPE to prevent injury from electrical arcs.
• 🛡 PPE rated above the calculated incident energy value increases the likelihood of protecting employees from the thermal effects of an arc flash.
• 🏢 A qualified person is one with demonstrated skills and knowledge related to electrical equipment operations and has received safety training to identify and reduce hazards.
• 📚 Continuing education and demonstration of necessary skills are required to maintain the skill level for working safely with electrical equipment.

Q & A

Why are certain fabrics like cotton, polyester, and wool considered hazardous in the context of arc flash incidents?

These fabrics are flammable and can continue to burn, which can lead to serious injuries due to their tendency to melt onto the skin, exacerbating burn injuries.

What is the role of properly rated Personal Protective Equipment (PPE) in preventing injuries from arc flash?

Properly rated PPE should limit the thermal energy level and pinch on the employee's body to one that does not cause worse than second-degree burns, although it may not prevent the melting of undergarments.

Why is it essential for undergarments to be made of non-melting material in arc flash scenarios?

Undergarments made of non-melting material are crucial to prevent them from melting onto the employee's skin, which can cause additional severe burns.

What is an arc-rated balaclava, and how does it protect against arc flash?

An arc-rated balaclava is a head and neck covering that is tested and rated for arc flash protection. It fits tightly against the skin with minimal air pockets, providing protection to the neck and head except for the facial areas of the eyes and nose.

Why is it not advisable to wear a balaclava for warmth as arc flash protection?

A balaclava intended for warmth may not have the necessary arc rating and may not meet the requirements of NFPA 70E, thus failing to provide adequate protection during an arc flash event.

What is the purpose of a barricade in electrical safety?

A barricade serves as a physical obstruction and warning device to limit access to areas with electrical hazards, ensuring that only qualified personnel can approach.

How should the placement of barriers and barricades be determined during electrical work?

The placement should be determined by maintaining the limited approach boundary distance or ensuring that energized conductors or circuit parts are de-energized and safe to approach.

What is the role of an attendant in providing manual signaling and alerting during electrical work?

The attendant's primary duty is to keep unqualified employees outside the work area where they might be exposed to electrical hazards, ensuring that only those qualified are present.

What is incident energy, and why is it important in selecting appropriate PPE?

Incident energy is the amount of thermal energy impressed on a surface during an electrical arc event, typically expressed in calories per square centimeter. It is crucial for selecting PPE rated above the calculated incident energy value to ensure protection.

What qualifies a person as a 'qualified person' in the context of NFPA 70E?

A qualified person is one who has demonstrated skills and knowledge related to the construction operations of electrical equipment and installations, has received safety training to identify hazards, and reduce associated risks.

Why is continuing education and demonstration of necessary skills important for maintaining the requisite skill level to work safely?

Continuing education and skill demonstration are important to ensure that employees remain up-to-date with safety practices and can work safely on electrical equipment, as the nature of electrical work requires ongoing learning and skill development.