NFPA vs NESC

[JimD1]

The NFPA -70E has 6 classes for arc flash,
class 0
class 1 - 4 cal/cm2,
class 2 - 8 cal/cm2,
class 2* - 8 cal/cm2
class 3 - 25 cal/cm2,
class 4 - 40 cal/cm2
How does this compare with the NESC?

Thanks,

Jim

 

[JCEdifice]

I think the NFPA got there numbers from IEEE 1584.

 

[dpc]

The NESC does not use that classification system at all. It simply states that PPE must have sufficient arc-rating.

PPE clothing manufacturers often rate clothing and equipment based on the NFPA 70E Hazard/Risk Categories.

David Castor

http://www.cvoes.com

 

[JimD1]

Thank you, are IEEE's the same as NFPA's?

 

[rbulsara]

IEEE 1584 provides detailed method and guidelines for "calculating" incident energy. IEEE does not define hazard categories.

NFPA 70E categorizes the hazard categories and PPE based on the level of incident energy, which can be determined from some short cut methods/tables (for specific conditions) included in NFPA 70E or can be calculated per IEEE 1584. IEEE method provides more accurate calculations. NFPA 70E also encourages use of IEEE method to calculate the incident energy.

This or any other like forum cannot be a substitute for reading and studying the pertinent standards and codes or getting a formal education on them.

Rafiq Bulsara

http://www.srengineersct.com