# bigger service



## papaotis (Jun 8, 2013)

i fell into a job i really dont want but got myself stuck with it because its part of the other job. have to make 2 200a services 1 400a service. i dont normally deal with 400a (three phase) but the way i read the 'book' this has to be 750 mcm wire in a 4" pipe. why can the poco use a wire half that size to feed it?


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## MTW (Aug 28, 2013)

Poco goes by their own load data and not the NEC to size their conductors. They know they have no need to size it per the NEC since the true load is almost always 1/2 to 1/3 the NEC calculation. Furthermore, the NEC would result in grossly oversized and wasteful transformer sizing


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## frenchelectrican (Mar 15, 2007)

papaotis said:


> i fell into a job i really dont want but got myself stuck with it because its part of the other job. have to make 2 200a services 1 400a service. i dont normally deal with 400a (three phase) but the way i read the 'book' this has to be 750 mcm wire in a 4" pipe. why can the poco use a wire half that size to feed it?


The POCO side they have it own rules and sizes they can deal with it.

Is this a overhead or underground service ?

If the overhead the POCO stop at the POA spice location so after that you have to bring in the correct size conductors.

why not parallel it ? it easier and cheaper in some case instead of fool around with big arse 750 Kcm ., 

the last one I done on 400 amp service is parallel 500 Kcm due the distance I have to pull.


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## Southeast Power (Jan 18, 2009)

papaotis said:


> i fell into a job i really dont want but got myself stuck with it because its part of the other job. have to make 2 200a services 1 400a service. i dont normally deal with 400a (three phase) but the way i read the 'book' this has to be 750 mcm wire in a 4" pipe. why can the poco use a wire half that size to feed it?


Im not convinced you need a full 800 amps for that service, we generally see the engineer size them according to the load.
The last 800 amp we did I think were 3x 350 AL.


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## MDShunk (Jan 7, 2007)

Some years back I posted a picture of a big service I did that was so large I had to have a custom fabricated weatherhead made. The PoCo fed it with #2 or something like that. I'll see if I can scare up that picture.


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## MDShunk (Jan 7, 2007)

Found it. Hidden in the stuff PhotoBucket bastids are holding for ransom.


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## MTW (Aug 28, 2013)

That remains the weirdest and ugliest service I have ever seen.


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## matt1124 (Aug 23, 2011)

MDShunk said:


> Found it. Hidden in the stuff PhotoBucket bastids are holding for ransom.


Looks about right. I’d be curious what that triplex is carrying with the building loaded up with a/c or electric heat!


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## MDShunk (Jan 7, 2007)

MTW said:


> That remains the weirdest and ugliest service I have ever seen.


I spent an awful lot of years specializing in "weird". 

You're right, though. I should have done about a dozen paralleled runs of SE cable. lain:


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## Cow (Jan 16, 2008)

That is a weird service! 



I expect the power co. to run smaller wire, but I've never had one that the ratio of mine to theirs was that far apart!



Just an observation, but why can no one point the splices up so they shed water like an umbrella? Every time I see overhead splices like that, I can't help but think, it's only a matter of time....


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## MTW (Aug 28, 2013)

MDShunk said:


> I spent an awful lot of years specializing in "weird".
> 
> You're right, though. I should have done about a dozen paralleled runs of SE cable. lain:


What's even weirder is a poco that allows an overhead service that large. Our poco requires anything over 800A to be padmount. If you don't agree to this, you're on your own and have to build and own it yourself and receive primary metering. I assume this fits into the latter category?


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## papaotis (Jun 8, 2013)

frenchelectrican said:


> The POCO side they have it own rules and sizes they can deal with it.
> 
> Is this a overhead or underground service ?
> 
> ...


teh pull is only 13 feet. one offset to get around the rain gutter. still looking for someone to make that offset. the big guys around here arent cooperating yet!


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## Cow (Jan 16, 2008)

papaotis said:


> teh pull is only 13 feet. one offset to get around the rain gutter. still looking for someone to make that offset. the big guys around here arent cooperating yet!



We can do the 4" offset, but shipping to cornfield America wouldn't be cheap...:biggrin:


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## pjholguin (May 16, 2014)

Have checked with your Supply Houses? Some of them will rent a bender or possibly bended it for you. :vs_cool:




papaotis said:


> teh pull is only 13 feet. one offset to get around the rain gutter. still looking for someone to make that offset. the big guys around here arent cooperating yet!


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## EJPHI (May 7, 2008)

MDShunk said:


> Found it. Hidden in the stuff PhotoBucket bastids are holding for ransom.


Say it ain't so MD, but it looks like all the conductors in each phase are in separate pipes.

EJPHI


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## MDShunk (Jan 7, 2007)

EJPHI said:


> Say it ain't so MD, but it looks like all the conductors in each phase are in separate pipes.
> 
> EJPHI


I've been doing this type of work an awful long time. It ain't so, and you don't have x-ray vision. Carry on...


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## Southeast Power (Jan 18, 2009)

EJPHI said:


> Say it ain't so MD, but it looks like all the conductors in each phase are in separate pipes.
> 
> EJPHI


That big, I suspect its aluminum.
No matter, it is nothing less than a piece of artwork. :smile:
I think I would have just put a weatherhead on each of those pipes but, it looks like you have two sets in each pipe, not enough holes in that plastic disk for that.


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## CTshockhazard (Aug 28, 2009)

MTW said:


> That remains the weirdest and ugliest service I have ever seen.



Weirdest yeah, but not enough strut straps for ugliest. :biggrin:


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## splatz (May 23, 2015)

MDShunk said:


> I've been doing this type of work an awful long time. It ain't so, and you don't have x-ray vision. Carry on...


I wouldn't mind hearing more about this job, how you decided to do it this way, and what you'd do if you were going to do it again...


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## Cow (Jan 16, 2008)

I'm picturing that weatherhead and the oversized conductor openings doubling as one of the worlds largest weatherhead beehives....


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## frenchelectrican (Mar 15, 2007)

Cow said:


> I'm picturing that weatherhead and the oversized conductor openings doubling as one of the worlds largest weatherhead beehives....



That going be instering if the bees actually do build a beehive there. 

I just have one customer place done not too long ago got a local beekeeper and I told POCO to kill the service drop so they did and they kinda stood in distance while beekeeper clean out much as he can and then put the rest to sleep then I have to clean up aftermath mess .,,


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## Wiresmith (Feb 9, 2013)

splatz said:


> I wouldn't mind hearing more about this job, how you decided to do it this way, and what you'd do if you were going to do it again...


what about leaving tails out for the poco for them to use and leave the meatballs in the box?(or other connection method)


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## EJPHI (May 7, 2008)

MDShunk said:


> I've been doing this type of work an awful long time. It ain't so, and you don't have x-ray vision. Carry on...


I feel better already:devil3:


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## MDShunk (Jan 7, 2007)

splatz said:


> I wouldn't mind hearing more about this job, how you decided to do it this way, and what you'd do if you were going to do it again...


That job has been done for at least 15 years, so I'm a little foggy on the particulars. I do remember it was around 2000-3000 amps, 208, single phase. It was a larger single phase service than that PoCo allowed, technically, but it was a short aerial section of an U/G network service. It gave them an opportunity to balance out the phases with other single phase customers, so they didn't much mind. It was a knitting mill of some sort being changed into apartments. Oh, why the big weatherhead instead of separate weatherheads? I actually forget. I think "because I wanted to", and no other reason.


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## flyboy (Jun 13, 2011)

MDShunk said:


> That job has been done for at least 15 years, so I'm a little foggy on the particulars. I do remember it was around 2000-3000 amps, 208, single phase. It was a larger single phase service than that PoCo allowed, technically, but it was a short aerial section of an U/G network service. It gave them an opportunity to balance out the phases with other single phase customers, so they didn't much mind. It was a knitting mill of some sort being changed into apartments. Oh, why the big weatherhead instead of separate weatherheads? I actually forget. I think "because I wanted to", and no other reason.


Interesting application. I don't think I've ever seen an overhead *208* single phase service and definetly not one that big. Or underground for that matter.

I know it was a long time ago, but do you remember where the utility abandoned the third phase and only brought over two phases and the neutral? At the pole where it came overhead or underground before going up the pole?


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## Going_Commando (Oct 1, 2011)

flyboy said:


> MDShunk said:
> 
> 
> > That job has been done for at least 15 years, so I'm a little foggy on the particulars. I do remember it was around 2000-3000 amps, 208, single phase. It was a larger single phase service than that PoCo allowed, technically, but it was a short aerial section of an U/G network service. It gave them an opportunity to balance out the phases with other single phase customers, so they didn't much mind. It was a knitting mill of some sort being changed into apartments. Oh, why the big weatherhead instead of separate weatherheads? I actually forget. I think "because I wanted to", and no other reason.
> ...


I cant say I've ever seen a 208v single phase service. I've worked on plenty of 3 phase 208v services with stack metering pulling single phase to apartments, but never single phase coming in. Any single phase service I've seen has been 120v (really old) or 120/240v.


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## MDShunk (Jan 7, 2007)

Going_Commando said:


> I cant say I've ever seen a 208v single phase service. I've worked on plenty of 3 phase 208v services with stack metering pulling single phase to apartments, but never single phase coming in. Any single phase service I've seen has been 120v (really old) or 120/240v.


Never? I bet you have and never realized it. The downtowns of many medium sized and larger cities are on what's called a "network". They put big ass three phase transformers in vault under the sidewalk here and there and feed as many customers off that underground network secondary as they can. Keeps the aerial lines from cluttering up the downtowns. If you have no need for 3-phase, you get 208 single phase.


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## MTW (Aug 28, 2013)

MDShunk said:


> Never? I bet you have and never realized it. The downtowns of many medium sized and larger cities are on what's called a "network". They put big ass three phase transformers in vault under the sidewalk here and there and feed as many customers off that underground network secondary as they can. Keeps the aerial lines from cluttering up the downtowns. If you have no need for 3-phase, you get 208 single phase.


I only worked on one service fed from a downtown network, and it was 3-phase, 200 amps. The poco required a fusible disconnect ahead of the meter with very high AIC rated fuses, for obvious reasons. I'm sure other buildings in the area were probably served with single phase 208 volts services, but never saw them since obviously all the metering was indoors.

I'm sure you know this but for those that don't - these networks are fed from transformers that are all in parallel, connected with a very large amount of conductor in terms of circular area. As such, they have unbelievably high levels of available fault current, hence the need for proper fusible protection at the main disconnect or ahead as required. Regular breakers will fail like grenades under fault conditions on a network.


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## MDShunk (Jan 7, 2007)

Yes, this is one of two main instances where you see "cold sequence metering". That meaning a disco ahead of the meter(s).


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