2000 amp service

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k3r

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I am building a 2000 amp service for a grocery store with no electrical plans of specs. I am planning on making five runs of 4 inch conduit with three runs of 600 mcm and one run of 500 mcm for the neutral. Is it still correct by code for me to drop a size on the neutral. Also I plan to run a 2/0 ground in your opinion is that the correct size for the service?
 
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What is the calculated load?

How was 2000 amps chosen?

What voltage?

How is a permit being obtained without plans?

You can drop your neutral many sizes if the calculations show it is of adequate size.
 
k3r said:
I am building a 2000 amp service for a grocery store with no electrical plans of specs. I am planning on . . .
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In your first sentence you said you had no plans. In your second sentence you said you were planning on doing something. I don't get it.
 
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So each conduit will have 3-600 kcmil and 1-500 kcmil conductors? Forget the #2/0 grounds.

As Bob said what's the calculated load or is it unknown?
 
k3r said:
I am building a 2000 amp service for a grocery store with no electrical plans of specs. I am planning on making five runs of 4 inch conduit with three runs of 600 mcm and one run of 500 mcm for the neutral. Is it still correct by code for me to drop a size on the neutral. Also I plan to run a 2/0 ground in your opinion is that the correct size for the service?
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Are you decreasing the size of the neutral on a WYE system?
 
iwire said:
Wye not? :smile:
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That is clever. :grin:


In our area, there are many jurisdictions that do not provide plan review for the electrical portions of jobs.

This store having no plans does not surprise people from where I work. This does present a problem just as in the OP's post.

Sizing the grounded conductor can be performed as in 250.24(C)(1)&(C)(2).

If one knows the calculations one can use 220.61.



It sounds like you are installing an "isolated phase installation" as in 300.3(B)(1)exception???

If so, are you sure how to install this properly, and do you have the blessing of your POCO?
 
k3r, a couriousity question.. do you know the supply AIC rating ?
 
for some reason, in this area, that has had the consistancy of many of the "old wives tales". I hear often: "you can't reduce the neutral on a wye system" and I have never found the origin.
 
Well we do not engineer or design plans or drawns , i only do distribution at work meaning install new work from the ground up .
All our one line drawns show a service or switchboard one line each by example maybe a 4000amp or 5000 amp mains section one .

If you calculate the main feeders into these switchboards section one which we check the electrical engineer on each project when plan review and estimate , take offs , value design or construction take offs as mistakes are made by engineers .

we see 100 % feeder and neutral on every project these are wye/ 480v 3 phase ,we also see on new projects today a increase in neutral size 200%on the neutral today .
Since ive been in the trade and i know you can reduce it meaning the neutral but i have never seen parralled runs with reduced neutrals even when its in the code. best to yas
 
iwire said:
It would have to be an odd building to require service with a 200% neutral.
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Bob,
Im surprised you mentioned that with all of the big work you guys do.
Did you do any of the co location work or data centers back in the dot com years?
We had 200% neutral busbars coming out of our substations.
 
iwire said:
It would have to be an odd building to require service with a 200% neutral.
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Well not all projects on the 200 % neutrals but a increase in the last few years ,and yes we kinda do some odd projects my last job was a Fat Bones and Grease Plant and before that a Turbine Plant meaning a plant that manufactures the turbine blades for power generators . We do some oddball stuff .Take care be safe
 
As you know a 'service' supplies the entire building not just the non-linear loads in the data center and regardless of the fact an entire building may be a data center the linear loads will still account for the majority of the loading on the service.

The HVAC load for instance, all that electronic data equipment has to be cooled and those AC units as far as I know are linear loads.

But forget that, go into one of these places and go to the service gear, many times they have at least basic power monitoring equipment at the service disconnect and look for the max neutral current and it will be a pretty low percentage of the service rating.

EEs like to cover their rear and I don't blame them a bit, it is really what they are paid for but at the same time I have seen a lot of what looks like waste to me. :smile:

Hey they want to pay us to put in 200% neutrals I will be glad to but I think the need for it is more hype then reality.:smile:
 
Well we have on all jobs after final and CO is completed a test on PF & amp checks that neutral return flow !! Guess what ?

Its normally low and yes i agree!! Its something that is extra work for me to pull in larger conductors and they always have some engineer who sizes the conduit to the minmmmmm code which is the next point i like to adriss dont go NEC code on feeders ENGINEERS !!! They calculate conduit fill by code minummmmm this really ticks me off .
They need to come out on my next 600 foot run that they picked the pipe size on and pull it .
Sorry the code says its ok .We only put 2 x 90 s in any run and never offset underground its my rule on distribution on every job.
Duck banks level straight . Any change in direction is a 20 foot sweep rules to go by .

They need to come out and pull what they call for
In real life comments ?
Best to yas
 
ohmhead said:
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Its normally low and yes i agree!! Its something that is extra work for me to pull in larger conductors and they always have some engineer who sizes the conduit to the minmmmmm code which is the next point i like to adriss dont go NEC code on feeders ENGINEERS !!! They calculate conduit fill by code minummmmm this really ticks me off .
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If you do the pulling calculations, you will find that there in not really much difference in the pulling force required to pull conductors in a code minimum sized raceway and an oversized one. If you think it really makes that much difference in the required labor, you could oversize the raceway from what the drawings say and make some additional profit on the job.
 
don_resqcapt19 said:
If you do the pulling calculations, you will find that there in not really much difference in the pulling force required to pull conductors in a code minimum sized raceway and an oversized one. If you think it really makes that much difference in the required labor, you could oversize the raceway from what the drawings say and make some additional profit on the job.
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Well we disagree with your statement heres why first ive been in the electrical trade for over 35 years and in the field working as a electrician same company for 26 years my crew only does power distribution work.
We install all underground work and we pull all the feeders on every job if you pull wire in a 4 inch conduit the pulling force is less then in a 3 1/2 inch conduit .
I dont need a formula to tell me this i know .

Heres why you can see it on pound gauge on our tugger you can feel the rope tighten up in your hands its not the straight run of conduit its the 90 part thats the issue its tight in the 90 and if the engineers came out and did a pull with us they would not get so close on most projects .
You need room for the basket or fingers and head make up no code book calculates this inside the conduit '

Just to add thers different jackets that dont pull easy .
And there is length & distance the bigger the conduit the better the pull its kinda common practice but then there is a formula for everything some times real work is what is the best test . If you use soap it goes better . Sorry but all ive done for years is run pipe pull wire and set equipment kinda pulled a few feeders in my time .We also work for the 23 largest electrical contactor in the USA so we have the best pulling tools you can buy today .
ive got all the toys and enjoy it everyday . There is more but i need my nap now . Best to yas i hope i did not offend anyone
 
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