New to posting on this Forum would like to ask a question to Mike Holt

[al ruckman]

I'm new to the form but not in utilizing all of Mike Holts seminars and continuing Education for various state licenses I hold in multiple states and with regards to NEC interpretations is there a way to get question to Mike Holt? I really would like to get his interpretation on some requirements in section 110.16 as it would apply to a Industrial complex. I realize 90% of this is for residential and commercial installation but I deal strictly with Industrial Complexes and I feel the all the examples are for the residential and commercial applications not very much on Industrial Complexes.

 

[tom baker]

Mike is seldom on this site. But there are many here who know the code. Ask away.
120.16 applies to all occupancies except dwelling units.
I see a lot of posts about industrial locations, there are only a few NEC sections with exceptions for industrial locations.

 

[al ruckman]

Thanks for the Reply. So my question I'm asking is in regards to 110.16 Arc-Flash Hazard Warning, Other than Dwelling Units. It is real easy in Commercial installation where the equipment defined in the code as Service ends and Feeders or Branch Circuits begins. The code spells out that only services need the more detailed Arc-Flash Hazard Warning Labels with the detailed information that is required in NFPA 70E and in 2022 it said Feeders as well. Well the new code know states that only Feeders of over a 1000A. Then this code cycle a new definition was added Branch Circuit, MotorMotor Branch Circuit) The circuit conductors, including equipment, between the motor branch-circuit short-circuit and ground-fault protective device and an individual motor. My interpretation on this new definition is that MCC's with individual bucket assemblies are by this definition NOT SERVICE equipment but branch circuits and only require the generic label that just warns qualified persons of the potential of the arc flash hazard. Even if people define these as Feeders I only have two Feeders over a 1000 amps most are 800 amps. I was just attempting to get a consensus of what Electrical Engineers with a PE would define this equipment. Of the ones I personally know they define MCC's as Feeders even then they are not over 1000A and need the more detailed Arc-Flash Label just the warning label. Thoughts

 

[Little Bill]

Be patient and some of the more knowledgeable guys will come along. Hopefully some PEs as well.

 

[don_resqcapt19]

Most industrial projects using that type of equipment will have the arc flash label on every bucket, even though not required by the NEC.

 

[jim dungar]

Most industrial projects using that type of equipment will have the arc flash label on every bucket, even though not required by the NEC.

No.
In my experience, putting a label on each bucket is information overload. Most of the places I installed labels wanted them on every two or three vertical sections. The MCC incident energy for each bucket would be based on its line side fault current which is the MCC bussing.

Complying with OSHA, and typically NFPA 70E, is usually an issue after equipment has been installed per the NEC and the facility is occupied.

 

[don_resqcapt19]

No.
In my experience, putting a label on each bucket is information overload. Most of the places I installed labels wanted them on every two or three vertical sections. The MCC incident energy for each bucket would be based on its line side fault current which is the MCC bussing.

Complying with OSHA, and typically NFPA 70E, is usually an issue after equipment has been installed per the NEC and the facility is occupied.

Yes, I should have said each MCC not each bucket.

 

[al ruckman]

I would like to thank everyone that has commented on my question. I agree with the statement that a applied label on every bucket is information overload. It's nice to get these thought from other people and I apricate it.

 

[mayanees]

Thanks for the Reply. So my question I'm asking is in regards to 110.16 Arc-Flash Hazard Warning, Other than Dwelling Units. It is real easy in Commercial installation where the equipment defined in the code as Service ends and Feeders or Branch Circuits begins. The code spells out that only services need the more detailed Arc-Flash Hazard Warning Labels with the detailed information that is required in NFPA 70E and in 2022 it said Feeders as well. Well the new code know states that only Feeders of over a 1000A. Then this code cycle a new definition was added Branch Circuit, MotorMotor Branch Circuit) The circuit conductors, including equipment, between the motor branch-circuit short-circuit and ground-fault protective device and an individual motor. My interpretation on this new definition is that MCC's with individual bucket assemblies are by this definition NOT SERVICE equipment but branch circuits and only require the generic label that just warns qualified persons of the potential of the arc flash hazard. Even if people define these as Feeders I only have two Feeders over a 1000 amps most are 800 amps. I was just attempting to get a consensus of what Electrical Engineers with a PE would define this equipment. Of the ones I personally know they define MCC's as Feeders even then they are not over 1000A and need the more detailed Arc-Flash Label just the warning label. Thoughts

It's true that the 2023 NEC edition will now require arc flash labels for feeder-supplied equipment rated 1000 amps or more. I suppose this is because the incident energy increases as the amperage increases. So industry could get by with minimal labelling at the service-entrance and for 1000 amps and larger equipment. But my experience in industry is that everything gets labelled because an arc flash Study is done for the entire facility's electrical system. IEEE 1584 which is the calculating standard makes a statement that arc flash is less likely for 240 Volt systems where bolted fault currents are below 2000 amps, so that is sometimes taken as a cutoff, but it's easier to just analyze the whole system.
Note that 240.67 and 240.87 require fuses and circuit breakers to have some means to reduce clearing time, which is a direct result of arc flash, in my opinion.
So even though arc flash incidents are rare, and the biggest risk is still shock protection, arc flash has made its way into the NEC and has impacted the cost of electrical systems.

 

[jtinge]

Remember to not confuse what a service is and what feeder-supplied is. Don't interchange the terms. Many will call the supply to a building a service out of habit when in fact it may be an electrical supply from customer owned transformers (separately derived system) and feeders. They often have similar requirements but a service has a direct connection to the local utility and separately derived systems and feeders are often found in industrial complexes with their own distribution system. Whether or not equipment is rated over or under 1000 amps makes no difference to whether it is service equipment or not. IM me and I can email you a comparison doc I generated that helps to clarify this.

 

[al ruckman]

I totally agree with you're comment Jtinge of interchanging the terms, Thank you. Your right that many will call the supply to a building section or other buildings on site a service and your explanation is exactly right at this facility we own our substation and do exactly what you described. I know exactly what the differences are between Services, Feeders & Branch Circuit. My problem is auditors that have never even looked at the code books for either NFPA 70 or NFPA70E and attempt to dictate what is required. We have auditors that come on site and conduct audits of the various Heath and Safety requirements dictated by corporate for the various sites though out the United states and issue a score based on what they find on how well the facilities are complying with the standards and every state is different, and most states have made addendums to the NEC when they adopt the code by reference for that states compliance. Even what version of the code that state will adopt and these auditors don't know this information. In Tennessee the Adopted by Reference for Rules of the department of commerce and insurance division of fire protection Chapter 0780-02-01 Electrical Installations is the 2017 version of the NEC, which I still have a copy of and that version did not require the detailed arc-flash labels that are required in the the newer revisions of the NEC. Tennessee even made an addendum to the code section 110.24 that this requirements shall be optional.

 

[mayanees]

I totally agree with you're comment Jtinge of interchanging the terms, Thank you. Your right that many will call the supply to a building section or other buildings on site a service and your explanation is exactly right at this facility we own our substation and do exactly what you described. I know exactly what the differences are between Services, Feeders & Branch Circuit. My problem is auditors that have never even looked at the code books for either NFPA 70 or NFPA70E and attempt to dictate what is required. We have auditors that come on site and conduct audits of the various Heath and Safety requirements dictated by corporate for the various sites though out the United states and issue a score based on what they find on how well the facilities are complying with the standards and every state is different, and most states have made addendums to the NEC when they adopt the code by reference for that states compliance. Even what version of the code that state will adopt and these auditors don't know this information. In Tennessee the Adopted by Reference for Rules of the department of commerce and insurance division of fire protection Chapter 0780-02-01 Electrical Installations is the 2017 version of the NEC, which I still have a copy of and that version did not require the detailed arc-flash labels that are required in the the newer revisions of the NEC. Tennessee even made an addendum to the code section 110.24 that this requirements shall be optional.

P&G used to do that back when I worked for them 20 years ago. There were six disciplines that they evaluated as part of the Technical Safety Program, one of which was the power system. I think you have a case to practice under the NEC code edition that it was installed under, at least to a normal AHJ. But if they're anything like P&G, they'll have specific requirements. Good luck.