Arc Flash analysis requirement

[Akten]

Hi,

I am working on a project where some HVAC equipment's are being replaced. The client's electrical equipment, including main switchboard, disconnects, etc does not have any Arc Flash labels on it. The original drawings are from around 50 years ago and it looks like they had some changes on their panels around 10-20 years ago so I am not sure why there isn't any Arc Flash labels on it. I believe there is some requirement by NFPA 70E that Arc Flash has to be updated every 5 years or when major upgrades happen. I am not sure if replacing Hvac equipment's is considered "major upgrade" but is the 5 years thing only applicable when there is an existing study already done? If there was no Arc Flash analysis done during the original installation, does the code (NEC or NFPA) require that an Arc Flash analysis be performed if we are doing any work on the panel (adding breaker, swapping a breaker to different rating, etc)? I'd like to ask for reference from the code in order to justify the Arc Flash requirement to the owner, if this is something they should be doing.

 

[jim dungar]

Arc Flash (NFPA 70E) is not a requirement of the NEC. The NEC requirements for Arc Flash warning labels do not mean a comprehensive arc flash study needs to be performed.

Compliance with NFPA 70E is usually enforced by OSHA and liability insurance policies.

 

[D. Castor]

Just to state this a little differently - there is no legal requirement (in the USA) to comply with NFPA 70E. They definitely should be following it, but it's not a legal requirement.

 

[tom baker]

What is the size of the service, voltage and phase? There is free software from Eaton you can use to calculate the available short circuit amps.

 

[Akten]

What is the size of the service, voltage and phase? There is free software from Eaton you can use to calculate the available short circuit amps.

The panel which feeds the HVAC equipment that is going to be replaced is 800A at 208V 3ph. This panel is however not the main service equipment, it is somewhere downstream, so I doubt the utility short circuit value will be helpful. Can you let me know the name of that free Eaton software?

 

[MyCleveland]

The panel which feeds the HVAC equipment that is going to be replaced is 800A at 208V 3ph. This panel is however not the main service equipment, it is somewhere downstream, so I doubt the utility short circuit value will be helpful. Can you let me know the name of that free Eaton software?

As an Engineer, or EC…you know the label requirement to indicate the AFC at each unit.
Did you exclude the calculations needed or hope the units coming out would have a label.

 

[tom baker]

800 amps would have a large poco transformer, and downstream fault current.

 

[tom baker]

The panel which feeds the HVAC equipment that is going to be replaced is 800A at 208V 3ph. This panel is however not the main service equipment, it is somewhere downstream, so I doubt the utility short circuit value will be helpful. Can you let me know the name of that free Eaton software?

Seems like there is an app since labeling is reqiured for new services. Or see what Mike Holt has on his website

 

[SVF]

I am in disagreement with our Electrical engineer. He wants to have incident energy ranges on the labels and I believe that NFPA requires the specific incident energy not a range. Any thoughts?

 

[jim dungar]

I am in disagreement with our Electrical engineer. He wants to have incident energy ranges on the labels and I believe that NFPA requires the specific incident energy not a range. Any thoughts?

What are incident energy ranges?
Everything I have ever seen is a single maximum incident energy value.
I have seen multiple values on labels, like when on normal or generator power, but they were usually dropped as being too confusing.

 

[mayanees]

I am in disagreement with our Electrical engineer. He wants to have incident energy ranges on the labels and I believe that NFPA requires the specific incident energy not a range. Any thoughts?

The requirement, if your company follows 70E, is to have an arc flash label with the worst-case incident energy listed, that being from any way that it is connected - typically either generator or Utility.