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Thread: Arc Flash PPE for HVAC work <= 480V

  1. #1
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    Arc Flash PPE for HVAC work <= 480V

    Will be doing NFPA 70E training with a mechanical service contractor who has HVAC technicians working on equipment typically operating at 480V and less. As you can expect, most of the commercial locations where they do service do not have Arc Flash Labels on their equipment. Per NFPA 70E, if an incident energy calculation has not been done, then the PPE Category method should be used for determining Arc Flash PPE. However, information such as the available fault current and clearing time are normally never available and trying to get this information would be extremely difficult. Just trying to be real! So looking for guidance on what they need to do to protect the workers. Ran across this document from the Mechanical Contractors Association of America:

    https://www.mcaa.org/pca/wp-content/...onalRelief.pdf

    What is basically states is when working on or around HVAC equipment at 480V and less that Category 2 PPE is required unless a risk assessment says it can be lower.

    Thoughts?

  2. #2
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    hmmmm

    Jim,

    You likely won't get many folks to agree with you on this because there could be that one installation that exceeds 8 calories, but generally speaking I think you're pretty safe with PPE 2.

    I looked back through some Studies we've completed and I couldn't find a single HVAC RTU disconnect that exceeded 8 calories, but of course that's not a carte blanch approval. I'd feel better looking upstream for the available fault current and protective device times in accordance with 70E table 130.7(C) (15)(a).

    The attached MCAA document loses credibility with their use of the term "pushing" 480 Volts, and it references 70E-2015. (the 2018 edition has been out for around seven months)

    But generally speaking, I think an 8-calorie suit will cover most HVAC installations.

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