Feeder cable size

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augie47

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There is a simple 3 step process that works in most all situations:
1. Calculate your load
2. Choose a conductor to carry the load after applying all adjustment factors and taking 110.14 into account
3. Select your overcurrent device based on Art 240.
 

hhsting

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It's not compliant, send the plans back. What is the problem? It's not your role to come up with a solution

Problem is when they don’t provide feeder cable size existing. They just say oh they are just adding simple receptacles, lights and only provide panel schedule. When you hold plans they complain or say oh we dont know whats existing they cant see the existing feeder sizes

Even this job hold the plans and they complain go above for short job like this
 

infinity

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New Jersey
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Problem is when they don’t provide feeder cable size existing. They just say oh they are just adding simple receptacles, lights and only provide panel schedule. When you hold plans they complain.

Even this job hold the plans and they complain go above for short job like this
Whoever "they" is, they should know better. Can one would assume that there is an engineer involved? If not then it's on the guy who's name is on the permit.
 

hhsting

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Whoever "they" is, they should know better. Can one would assume that there is an engineer involved? If not then it's on the guy who's name is on the permit.

Their is always professional engineer (PE) involved with their stamp. Ofcourse if feeders are in raceway or hidden how do they know the size if they are not electrician they cant see whats in panelboard or open them. Their is no way to tell existing feeder size
 
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DrSparks

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Location
Madison, WI, USA
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There is a simple 3 step process that works in most all situations:
1. Calculate your load
2. Choose a conductor to carry the load after applying all adjustment factors and taking 110.14 into account
3. Select your overcurrent device based on Art 240.
Well put

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roger

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Their is always professional engineer (PE) involved with their stamp. Ofcourse if feeders are in raceway or hidden how do they know the size if they are not electrician they cant see whats in panelboard or open them. Their is no way to tell existing feeder size
In your first post you said the feeders were 500's so why are you adding what if's now? The feeder size is known and the respondents in this thread have given you the correct answers and advice

Roger
 

hhsting

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Glen bunie, md, us
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In your first post you said the feeders were 500's so why are you adding what if's now? The feeder size is known and the respondents in this thread have given you the correct answers and advice

Roger

Yes in this it is given and know but their are cases and many it was not shown or was told they cannot find it they are not electrician only professional engineer so they cant open

Maybe change in NEC code to include feeder cable sizes feeding panelboard, switchboard, transformer etc with directory would be great?
 

DrSparks

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Location
Madison, WI, USA
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Master Electrician and General Contractor
Yes in this it is given and know but their are cases and many it was not shown or was told they cannot find it they are not electrician only professional engineer so they cant open

Maybe change in NEC code to include feeder cable sizes feeding panelboard, switchboard, transformer etc with directory would be great?
A PE is allowed to use other formulas to determine ampacity. I think about that every time I wire #12 wire to #18 wire in an appliance. There are many "engineering supervision" exceptions in the code.

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hhsting

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Glen bunie, md, us
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Junior plan reviewer
A PE is allowed to use other formulas to determine ampacity. I think about that every time I wire #12 wire to #18 wire in an appliance. There are many "engineering supervision" exceptions in the code.

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If PE cannot see the cable, its hidden or if its not know due to any reasons since they cannot open panelboard due to not being electrician then they dont use any formula. PE only says they dont know they cannot see cable type size or see it or tell the existing. Simple.

Telling you all feeder cable sizes installed at site feeding panelboard, switchboard, transformers etc need to be with directory next code cycle
 
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infinity

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New Jersey
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If PE cannot see the cable, its hidden or if its not know due to any reasons since they cannot open panelboard due to not being electrician then they dont use any formula. PE only says they dont know they cannot see cable type size or see it or tell the existing. Simple.

Telling you all feeder cable sizes installed at site feeding panelboard, switchboard, transformers etc need to be with directory next code cycle
It's the designers problem if they cannot access the existing equipment not yours. You look at what they submitted and give it the big REJECT. Then they can resubmit with conductor sizes. Next....
 

roger

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Fl
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Yes in this it is given and know but their are cases and many it was not shown or was told they cannot find it they are not electrician only professional engineer so they cant o

Maybe change in NEC code to include feeder cable sizes feeding panelboard, switchboard, transformer etc with directory would be great?
Ok but at least I can make proposal to the CMP about it. Link?
Look in the back of your code book

Roger
 

don_resqcapt19

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Illinois
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retired electrician
Nothing in 240 changes the ampacity of the conductors, but sometimes the rules in 240 permit you to use an OCPD with a rating that is greater than the conductor ampacity.
All conductors must have an ampacity at least equal to the calculated load.
 

don_resqcapt19

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retired electrician
Their is always professional engineer (PE) involved with their stamp. Ofcourse if feeders are in raceway or hidden how do they know the size if they are not electrician they cant see whats in panelboard or open them. Their is no way to tell existing feeder size
Then they are required to hire someone qualified to open the panel to complete their design. If they don't verify the existing conditions, they have no business putting their stamp on the design.
 

roger

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Fl
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Then they are required to hire someone qualified to open the panel to complete their design. If they don't verify the existing conditions, they have no business putting their stamp on the design.
Agree and most PE firms I dealt with had field electricians on their payroll for this and quality control issues

Roger
 
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