Fault currents motor contribution

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MyCleveland said:
Bottleneck…? Not an excuse. No experience, why are you selling a partial design service. You know this is not stated going in.

I agree on larger projects or items like PaulE brought up. It remains that what is being submitted is an incomplete design and ONLY a conditional permit should be issued.

Jim D brought up pages ago regarding how sometimes when the report finally appears, brand new equipment needs to ripped out. Are you eating this…no, the contractors are. Discussed this with a few GCs and all stated they ended up eating it. Fair?
None wanted to upset the customer or afraid they would get pulled from bidding future work.
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Its not an excuse. It's a fact that designs change and evolve during construction. There is no reason why some construction activities could not progress until the design becomes more complete. This is why many jurisdictions allow deferred submittals. Bottleneck because it would be inefficient to pause the whole project just because more exact conductor lengths, motor nameplate and other data are not known. Its not always the GC that eats the cost for equipment replacement, but it's 100% on them if they went ahead and made decisions on their own based on a limited understanding. The construction industry is full of risk. You will never get rid of that even with a perfect power system study up front.
 
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MyCleveland said:
Jim D brought up pages ago regarding how sometimes when the report finally appears, brand new equipment needs to ripped out. Are you eating this…no, the contractors are. Discussed this with a few GCs and all stated they ended up eating it. Fair?
None wanted to upset the customer or afraid they would get pulled from bidding future work.
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The reason equipment needs to be ripped out is often because of the electrical contractor.

They either ignored the requirement to conduct a study until the AHJ asked for it prior to an occupancy certificate.
There was such a delay in ordering the equipment so the project schedule would be impacted while waiting to for the study results.
The design was done by the contractor using 'sales tools' rather than detailed specs.
The utility supplied a different transformer than was anticipated.
 
xptpcrewx said:
Its not an excuse. It's a fact that designs change and evolve during construction. There is no reason why some construction activities could not progress until the design becomes more complete. This is why many jurisdictions allow deferred submittals. Bottleneck because it would be inefficient to pause the whole project just because more exact conductor lengths, motor nameplate and other data are not known. Its not always the GC that eats the cost for equipment replacement, but it's 100% on them if they went ahead and made decisions on their own based on a limited understanding. The construction industry is full of risk. You will never get rid of that even with a perfect power system study.
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What would you suggest in my case then leave a note conditionally approved AIC rating subject to be field approved based on final short circuit study with motor contribution?
 
jim dungar said:
The reason equipment needs to be ripped out is often because of the electrical contractor.

They either ignored the requirement to conduct a study until the AHJ asked for it prior to an occupancy certificate.
There was such a delay in ordering the equipment so the project schedule would be impacted while waiting to for the study results.
The design was done by the contractor using 'sales tools' rather than detailed specs.
The utility supplied a different transformer than was anticipated.
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The discussions I had with GCs…they did not imply the EC was guilty of anything except being forced into being part of design team via project specifications.

Yes, equipment is being ordered…told to place order because of time factors even though everyone is aware this mystery report may land and cause changes.

Why not keep the EE work/study as the responsibility of the design team and remove the EC from this and let them build.

Utility provides a different tranny should cost the owner.
 
MyCleveland said:
Why not keep the EE work/study as the responsibility of the design team and remove the EC from this and let them build.
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Granted I have only done work in Illinois, Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin, but I have never seen the general contractor not hold the electrical contractor responsible.

The final study cannot usually be done until the final construction approval has been given and all value engineering is completed. Typical issues that just be resolved include: which equipment vendor is chosen, are conductors going to be copper or aluminum, cable or conduit, equipment room changes.

I have redone some studies as much as 8 times over the course of a 2 year project due to changes during construction.
 
jim dungar said:
Granted I have only done work in Illinois, Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin, but I have never seen the general contractor not hold the electrical contractor responsible.

The final study cannot usually be done until the final construction approval has been given and all value engineering is completed. Typical issues that just be resolved include: which equipment vendor is chosen, are conductors going to be copper or aluminum, cable or conduit, equipment room changes.

I have redone some studies as much as 8 times over the course of a 2 year project due to changes during construction.
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Why the list of states, I never questioned your credentials.

I am not even sure we are arguing for or against the same thing anymore.

I will tap out now.
 
MyCleveland said:
Why the list of states, I never questioned your credentials.

I am not even sure we are arguing for or against the same thing anymore.

I will tap out now.
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We are not arguing.
I was clarifying a region of the country where I have experience with construction practices.
 
hhsting said:
No PE engineer would take responsibility or approve another PE. Yes it does two different PEs would convolute things.

NEC 2023 include calculations to be provided during plan review stage 110.9 110.10
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There are no PIs to put a requirement like that in 110.9 or 110.10 for the 2023 code.
You have plenty of time to write of PIs for a 2026 code change. The will have to be submitted by sometime in the fall of 2023.
 
hhsting said:
Never got response post #84
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You are asking me to break my word…

I did respond, see #119, but I would ask you not since time has expired.

Honestly, I have been listening to ECs, let’s say complain, on this topic for over 10 years and I do not believe one chimed in and offered an opinion. Except one to punt to the EI. Disappointing even more, at least to me, is no other engineer seems to agree.
Status quo it is.

You have been given your path “hh”, time to let it go.
 
Well its not only NEC 2017 Section 110.24(A) but also the following sections that require available fault current be marked or be documented and made available to authorized inspect

409.22(B) (documented and made available)
430.99 (documented and made available)
440.10(B) (documented and made available)
620.51(D)(2) (mark)
670.5(2) (mark)
620.16(A) (mark)
700.5(E)(marked)
701.5(d)(marked)
702.5(marked)
708.24(e)(marked)


And in NEC 2020
480.6 (marked)

I am not in NEC 2020 but I am in NEC 2017 so how can one just mark plans and say ok? Do you all think NEC 2017 Articles and sections above require short circuit study be delivered at plan review stage? How else max available fault current be found otherwise
 
electrofelon always gives you good advice.
Buy you a stamp "AIC ratings to be checked on inspection"
See Post #96
 
hhsting said:
Well its not only NEC 2017 Section 110.24(A) but also the following sections that require available fault current be marked or be documented and made available to authorized inspect

409.22(B) (documented and made available)
430.99 (documented and made available)
440.10(B) (documented and made available)
620.51(D)(2) (mark)
670.5(2) (mark)
620.16(A) (mark)
700.5(E)(marked)
701.5(d)(marked)
702.5(marked)
708.24(e)(marked)


And in NEC 2020
480.6 (marked)

I am not in NEC 2020 but I am in NEC 2017 so how can one just mark plans and say ok? Do you all think NEC 2017 Articles and sections above require short circuit study be delivered at plan review stage? How else max available fault current be found otherwise
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But none of that happens at the plan review or the permit stage of the project...in most cases that marking is one of the very last things that is done.
 
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