• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Arc Flash and Coordination studies - are they code required?

Y

Yikes

Gold Member
Joined
Nov 2, 2009
Messages
3,084
Location
Southern California
I'm working on an existing building where they are swapping out the main switchgear and installing a step-down transformer to feed old load centers. The contractor is asking if an "Arc Flash and Coordination study" is required.
To be honest I hadn't heard of it before, but a quick google search mentions NFPA 70e (I don't have a copy), and it looks like it's more of a periodic systems testing issue for ongoing employee safety, rather than an electrical code requirement during construction. Does anyone else have experience with this? Should I just refer it back to the client's facility manager to decide whether they need it?
 
I believe it is an OSHA requirement rather than a code requirement. You can view NFPA 70E at:

NFPA 70E®: Standard for Electrical Safety in the Workplace®

<p>This standard addresses electrical safety-related work practices, safety-related maintenance requirements, and other administrative controls for employee workplaces that are necessary for the practical safeguarding of employees relative to the hazards associated with...
www.nfpa.org
 
As steveray says, it is a code requirement. Sometimes I feel that I am the only one requiring this. I always write it on the plan during a review. Every time I ask for the the label the electricians say they never heard of it. I hadn't required it for 200A commercial services and lower but I probably should.

110.24 (A) always requires it
110.24 (B) Modifications has an exception for industrial installations where they have qualified persons to service the equipment.
 
steveray said:
110.24 would require you to post the available fault current....I know there is some other stuff around there too....
Click to expand...

It appears that California Electrical Code 110.24(A) posting requirements are about the equipment ratings not about performing the test.
110.24(B) is about verifying or recalculating when the utility provider's service changes.

In our case, the utility provider gave us the arc fault of 30,000 AIC in 2021 when the design took place. Now that it is being installed, I assume that info is sufficient for our posting purposes.

110.24 Available Fault Current​
​
(A) Field Marking​
​
Service equipment at other than dwelling units shall be legibly marked in the field with the maximum available fault current. The field marking(s) shall include the date the fault-current calculation was performed and be of sufficient durability to withstand the environment involved. The calculation shall be documented and made available to those authorized to design, install, inspect, maintain, or operate the system.​
Informational Note: The available fault-current marking(s) addressed in 110.24 is related to required short-circuit current ratings of equipment. NFPA 70E-2015, Standard for Electrical Safety in the Workplace, provides assistance in determining the severity of potential exposure, planning safe work practices, and selecting personal protective equipment.​
​
​
(B) Modifications​
​
When modifications to the electrical installation occur that affect the maximum available fault current at the service, the maximum available fault current shall be verified or recalculated as necessary to ensure the service equipment ratings are sufficient for the maximum available fault current at the line terminals of the equipment. The required field marking(s) in 110.24(A) shall be adjusted to reflect the new level of maximum available fault current.​
Exception: The field marking requirements in 110.24(A) and 110.24(B) shall not be required in industrial installations where conditions of maintenance and supervision ensure that only qualified persons service the equipment.​
 
We have also been providing comments for the arc-flash requirements on the plan review since many "forget about it"
 
You must log in or register to reply here.
Top