Fault currents motor contribution

[jim dungar]

As much as I disagree, I can see your logic, but how then do you provide labels on items downstream mentioned with no calc, or are we back to it’s all done after the permit process.

The labels have to be field installed because they are based on the installed system. How can this happen at the plan review stage prior to a permit.

 

[MyCleveland]

The labels have to be field installed because they are based on the installed system. How can this happen at the plan review stage prior to a permit.

I won’t argue that Jim, I am only trying to get at study must be done….any permit issued must be conditional, and that study should rest in the city archives for all to see.

 

[xptpcrewx]

As much as I disagree, I can see your logic, but how then do you provide labels on items downstream mentioned with no calc, or are we back to it’s all done after the permit process.

I’m not advocating for not doing a study. I always recommend it be done, especially done per industry recommend practices and executed by a licensed professional. All I’m saying is the NEC does not require a short-circuit study, and does not specifically address how to achieve compliance. It merely states to select and coordinate devices appropriately - whether it’s calculated, given, overestimated, etc.

Yes, arc-flash and coordination are done after the permit is issued, after you’ve selected the equipment/devices and generated protection settings. For certain types of occupancies, the permit process may have a stage where the Engineer of Record is required to certify compliance or submit of the power system study report to the building department for review. Again, this is an administrative process beyond the scope of the NEC.

 

[hhsting]

Don
Going through Ohio Building Code, 2017.

Chapter 1 Administration
106.1.1 Information on construction documents
List of 17 items…number 17, Additional information required by the building official to determine compliance. Seems open ended where a SCC study could be requested.

Did you find that in state building code Not county building code? Can you please let me know so i can check here?

 

[xptpcrewx]

If the lawyer argues at the time of plan submission, no such administrative procedure existed to perform a fault study, and the plan reviewer even approved the plans then Plan reviewer would also be liable no?

Maybe maybe not. Depends on if you executed the work within the scope of your authority. As plan reviewer, you aren’t verifying the entire design. Mostly spot checking within your competency and administrative rules. This is one reason a signed/sealed set of plans is required. Because it is certification in of itself the design is complete and adequate.

 

[xptpcrewx]

I won’t argue that Jim, I am only trying to get at study must be done….any permit issued must be conditional, and that study should rest in the city archives for all to see.

One thing to consider is it’s not the Engineer of Record who is typically performing the power system study, but an equipment manufacturer or third party contractor hired through one of the electrical contractors.

 

[hhsting]

One thing to consider is it’s not the Engineer of Record who is typically performing the power system study, but an equipment manufacturer or third party contractor hired through one of the electrical contractors.

So on the plans if you get something like following for new building:

Series rating shall be provided between meterstacks main breaker to meterstack feeder breaker to downstream panelboard

Their is no AIC rating provided for meter stacks, down stream panelboard.

No available fault current provided meterstacks, panelboard.

Since fault currents cannot be asked and AIC rating cannot be asked, Would as plan reviewer ask designer to provide note series rating shall not be used where 240.86(C) applies or would you ask for fault currents and AIC ratings and verify 240.86(C) applies or not?

 

[MyCleveland]

Maybe maybe not. Depends on if you executed the work within the scope of your authority. As plan reviewer, you aren’t verifying the entire design. Mostly spot checking within your competency and administrative rules. This is one reason a signed/sealed set of plans is required. Because it is certification in of itself the design is complete and adequate.

Your last sentence…you, myself, and most everyone here is subject to review. A PE is simply your qualification to be in the game, it alone does not guarantee against errors or emissions.

 

[xptpcrewx]

So on the plans if you get something like following for new building:

Series rating shall be provided between meterstacks main breaker to meterstack feeder breaker to downstream panelboard

Their is no AIC rating provided for meter stacks, down stream panelboard.

No available fault current provided meterstacks, panelboard.

Since fault currents cannot be asked and this AIC rating, Would as plan reviewer ask designer to provide note series rating shall not be used where 240.86(C) applies or would you ask for fault currents and AIC ratings and verify 240.86(C) applies or not?

Could you leave a note for the inspector to check with the permit holder how series ratings were applied? Whether it be 240.86(A) or 240.86(B) and (C).

 

[MyCleveland]

One thing to consider is it’s not the Engineer of Record who is typically performing the power system study, but an equipment manufacturer or third party contractor hired through one of the electrical contractors.

I understand this completely, more the reason a conditional permit must be issued because the design is not complete.

The owner should be told his EE of record, well of record for everything less the power system.

Have you discussed this with the vendors providing these studies, ALL I have discussed with do not believe they even hold any liability

 

[hhsting]

Could you leave a note for the inspector to check with the permit holder how series ratings were applied? Whether it be 240.86(A) or 240.86(B) and (C).

I could leave a note but meterstacks schedule and panel schedule would not have AIC rating. So as plans reviewers approve without any AIC rating? You know contractor will put whatever they want lowest AIC equipment. Should their not be note on plans power study to be provided or approved but AIC rating determined by short circuit study?

 

[xptpcrewx]

Have you discussed this with the vendors providing these studies, ALL I have discussed with do not believe they even hold any liability

As someone who is experienced with working for large manufacturers, I can tell you they are wrong. This is a frequent thing I have to deal with. They don’t understand the law. Company employees performing power system studies often believe they are shielded/protected.

Power system studies are considered engineering reports/analysis with recommendations, and many state laws require such work be performed and signed/sealed by licensed engineers. It’s the licensed professional that is accountable to the state board and not necessarily the company.

A funny thing I hear all the time is if you don’t sign/seal the study then you aren’t liable. False. Not signing/sealing a document in accordance with your state laws only increases the liability you already had in the matter.

What do you think the manufacturers insurance company is going to say when a claim is filed against the company (and the individual) when legal comes to find out state/local law regarding the practice of professional engineering were not followed? Do you think there will be a good legal defense against liability from failure to follow codes, negligence, errors/omissions, standard duty of care? I don’t think so.

 

[don_resqcapt19]

And these admin rules are usually on AHJ website stating what documents are require for plan review?

They have to be legally adopted rule by the unit of government that adopted the code.

However once there are legally adopted rules they would be provide to the permit requester in some form that could include publishing them on the AHJ webpage.

 

[don_resqcapt19]

Don
Going through Ohio Building Code, 2017.

Chapter 1 Administration
106.1.1 Information on construction documents
List of 17 items…number 17, Additional information required by the building official to determine compliance. Seems open ended where a SCC study could be requested.

Probably so open ended that it is not legally enforceable should someone care to take the issue to court.

 

[hhsting]

They have to be legally adopted rule by the unit of government that adopted the code.

However once there are legally adopted rules they would be provide to the permit requester in some form that could include publishing them on the AHJ webpage.

Ok alright. I didnt find anything like that in our website. So I cant really ask for short circuit study or fault current calculation.

Anyways the plans that I have now for brand new high rise building have panelboard schedules, meterstacks schedules without AIC ratings.

You know contractor will install the lowest rated AIC device. Should the plans be approved noting that AIC rating to be provided by short circuit study with motor contribution or not?

 

[electrofelon]

I could leave a note but meterstacks schedule and panel schedule would not have AIC rating. So as plans reviewers approve without any AIC rating? You know contractor will put whatever they want lowest AIC equipment. Should their not be note on plans power study to be provided or approved but AIC rating determined by short circuit study?

Just put a note on plans "AIC ratings to be checked on inspection" how hard is that? The last set of plans I submitted, I had ALL the AIC rating data and ALL the available fault current data. Included the series rating chart and everything, and plan reviewer still put "AIC ratings to be verified in field by inspector". Had to go over it twice with two different inspectors in the field. Showed them the relevant series rating chart and everything, even though it was ALL in the plans. So long story short, it is totally fine to have field verification of stuff. You seem to think you need all the data and need to give a complete and final approval of EVERYTHING.

 

[hhsting]

Just put a note on plans "AIC ratings to be checked on inspection" how hard is that? The last set of plans I submitted, I had ALL the AIC rating data and ALL the available fault current data. Included the series rating chart and everything, and plan reviewer still put "AIC ratings to be verified in field by inspector". Had to go over it twice with two different inspectors in the field. Showed them the relevant series rating chart and everything, even though it was ALL in the plans. So long story short, it is totally fine to have field verification of stuff. You seem to think you need all the data and need to give a complete and final approval of EVERYTHING.

Ok but this is like 12 stories high rise. If it was small tenant fit out or even four stories building then I would have been done with.

Stakes are higher. There are like 4-480/277v three phase switchboards 2000A two in garage and two in first floor. Explosion due to overduty equipment can cause high rise to fall you know. Worse someone getting hurt.

 

[MyCleveland]

Probably so open ended that it is not legally enforceable should someone care to take the issue to court.

Are we not discussing the case where the study will be provided, just whether or not it happens with plan submitted or later via EC/gear supplier.
No one would make a court challenge on this, we are down to a timing issue of when submittal will be provided.
Are you stating a permit cannot be conditional based on this lack of data ?

Should the owner not be fully aware his engineer of record is not the one providing this info ?

 

[electrofelon]

Ok but this is like 12 stories high rise. If it was small tenant fit out or even four stories building then I would have been done with.

Stakes are higher. There are like 4-480/277v three phase switchboards 2000A two in garage and two in first floor. Explosion due to overduty equipment can cause high rise to fall you know. Worse someone getting hurt.

again, what is wrong with putting a note "AIC to be verified in field"? The inspectors look at all the write ups on the plans, thats what they do.

 

[don_resqcapt19]

Ok alright. I didnt find anything like that in our website. So I cant really ask for short circuit study or fault current calculation.

Anyways the plans that I have now for brand new high rise building have panelboard schedules, meterstacks schedules without AIC ratings.

You know contractor will install the lowest rated AIC device. Should the plans be approved noting that AIC rating to be provided by short circuit study with motor contribution or not?

I see no issue with you rejecting the plans based on incomplete information and requiring a revised set of plans that show the required SSCR and AIC ratings.

But even that could be an issue where the administrative rules do not require the submission of plans with the permit application.