# 400A resi service.



## tates1882 (Sep 3, 2010)

220/221 said:


> This is what we trpically use out here when we need a big resi service.
> 
> 200A 40 space main breaker/bus on the outside and another 200A 40 space panel, sometimes mounted ourside, next to the service, sometimes (in this case) mounted inside and feed with cable (4/0 Al here).
> 
> ...


We have to pull 350mcm al here.


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## Dennis Alwon (May 9, 2009)

tates1882 said:


> We have to pull 350mcm al here.


His is a clear violation once another breaker is added to the exterior panel. The knockout above the bus bar is also not compliant without sealing locknuts but AZ does things differently.


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## captkirk (Nov 21, 2007)

220/221 said:


> This is what we trpically use out here when we need a big resi service.
> 
> 200A 40 space main breaker/bus on the outside and another 200A 40 space panel, sometimes mounted ourside, next to the service, sometimes (in this case) mounted inside and feed with cable (4/0 Al here).
> 
> ...


 Oh man I love that panel combo.....nice and clean

Last week I did a service change that required me to put a 200 disco switch outside and had to run ser inside to panel... I though I was being generous by ordering 50 feet of cable and I had about less than a foot left in scrap...talk about to close for comfort..


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## 220/221 (Sep 25, 2007)

Dennis Alwon said:


> His is a clear violation once another breaker is added to the exterior panel. .


Que?



> The knockout above the bus bar is also not compliant without sealing locknuts but AZ does things differently


I'll give you that one :jester:


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## rnr electric (Jan 29, 2010)

Can i assume that the breaker on th right serves the interior,(fed from busbar) and the one on the left serves the distribution? (only, doesnt serve the 200 on right)


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## rnr electric (Jan 29, 2010)

what?? NO BUSHING ON KO???


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## rexowner (Apr 12, 2008)

220/221 said:


> Que?
> 
> Because 310.15(B)(6) doesn't apply, and therefore you need to use
> Table 310.16, which requires a larger conductor than 4/0 AWG assuming
> 75C termination.


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## 220/221 (Sep 25, 2007)

> Because 310.15(B)(6) doesn't apply, and therefore you need to use
> Table 310.16


Why doesn't it apply??

*Table 310.15(B)(6) Conductor Types and Sizes for*
*120/240-Volt, 3-Wire, Single-Phase Dwelling Services and*
*Feeders.* Conductor Types RHH, RHW, RHW-2, THHN,
THHW, THW, THW-2, THWN, THWN-2, XHHW,
XHHW-2, *SE*, USE, USE-2
Conductor (AWG or kcmil)
Service or Feeder
Rating (Amperes) Copper
*Aluminum* or
Copper-Clad
Aluminum​100 4 2
110 3 1
125 2 1/0
150 1 2/0
175 1/0 3/0
*200* 2/0 *4/0*
225 3/0 250
250 4/0 300
300 250 350
350 350 500​400 400




> Can i assume that the breaker on th right serves the interior,(fed from busbar) and the one on the left serves the distribution? (only, doesnt serve the 200 on right)


Yes.



> what?? NO BUSHING ON KO???


 
Come on. Give me a _little_ credit :laughing:


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## NolaTigaBait (Oct 19, 2008)

zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz.....Use 4/0 and be done with it....Either let us use the stupid chart or get rid of it....


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## Dennis Alwon (May 9, 2009)

4/0 is only legal if the feeder carries the entire load of the service. Once a breaker is added in the exterior panel the 4/0 se cable is no longer compliant because it must follow 310.16


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## 220/221 (Sep 25, 2007)

Dennis Alwon said:


> 4/0 is only legal if the feeder carries the entire load of the service. Once a breaker is added in the exterior panel the 4/0 se cable is no longer compliant because it must follow 310.16


 
Is the bolded section what you are talking about?

(6) 120/240-Volt, 3-Wire, Single-Phase Dwelling Services
and Feeders*.*​​​​For individual dwelling units of onefamily,
two-family, and multifamily dwellings, conductors,
as listed in Table 310.15(B)(6), shall be permitted as
120/240-volt, 3-wire, single-phase service-entrance conductors,
service-lateral conductors, and feeder conductors
that serve as the main power feeder to each dwelling unit
and are installed in raceway or cable with or without an
equipment grounding conductor. *For application of this section,*
*the main power feeder shall be the feeder between the*
*main disconnect and the panelboard that supplies, either by*
*branch circuits or by feeders, or both, all loads that are part*
*or associated with the dwelling unit. *The feeder conductors
to a dwelling unit shall not be required to have an allowable
ampacity rating greater than their service-entrance conductors.
The grounded conductor shall be permitted to be
smaller than the ungrounded conductors, provided the requirements​
of 215.2, 220.61, and 230.42 are met.


If so, I don't even understand the verbage. Did they leave out a word? Misplace a comma?

Leaving out the qualifications for clarity, it's not written in proper English.

*The main power shall be the feeder between the main disco and the panelboard, all loads that are part or associated with the dwelling unit.*

Someone enlighten me, please.


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## Dennis Alwon (May 9, 2009)

220/221 said:


> Is the bolded section what you are talking about?


Correct.....


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## 220/221 (Sep 25, 2007)

Dennis Alwon said:


> Correct.....


Got it. I was leaving out a couple words.

*The main power shall be the feeder between the main disco and the panelboard that supplies... all loads that are part or associated with the dwelling unit.*

Still confusing but, since there isn't a *main disco* that *suplies power to all loads*, 310.15 doesn't apply.


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## NolaTigaBait (Oct 19, 2008)

Nevermind...still think 4/0 is ok even though the experts say it isn't..


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## user4818 (Jan 15, 2009)

Since this cable is connected to a main breaker wouldn't that make this a "main power feeder." Personally, I think the 4/0 is fine. Just my opinion of course. It seems this might be a grey area.


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## Dennis Alwon (May 9, 2009)

Peter D said:


> Since this cable is connected to a main breaker wouldn't that make this a "main power feeder." Personally, I think the 4/0 is fine. Just my opinion of course. It seems this might be a grey area.


It is a 400 amp service and presumably there will be other circuits in the exterior panel. It is not a gray area at all. Is 4/0 fine-- probably so but the code is clear on this.


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## NolaTigaBait (Oct 19, 2008)

Dennis Alwon said:


> It is a 400 amp service and presumably there will be other circuits in the exterior panel. It is not a gray area at all. Is 4/0 fine-- probably so but the code is clear on this.



I dont think its clear at all. If it was, there wouldn't be any confusion.


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## electures (Oct 23, 2008)

220/221 said:


> This is what we trpically use out here when we need a big resi service.
> 
> 200A 40 space main breaker/bus on the outside and another 200A 40 space panel, sometimes mounted ourside, next to the service, sometimes (in this case) mounted inside and feed with cable (4/0 Al here).
> 
> ...


1. Is there a connector on the SER? 
2. All branch circuits through one connector?


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## NolaTigaBait (Oct 19, 2008)

electures said:


> 1. Is there a connector on the SER?
> 2. All branch circuits through one connector?


Yes, we know already....Don't even go there, don't waste your time...Its accepted here and where he lives....next..


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## electures (Oct 23, 2008)

NolaTigaBait said:


> Yes, we know already....Don't even go there, don't waste your time...Its accepted here and where he lives....next..


 
OH!


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## NolaTigaBait (Oct 19, 2008)

electures said:


> OH!


:laughing:...Yes, I live in Hack City


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## 220/221 (Sep 25, 2007)

electures said:


> 1. Is there a connector on the SER?
> 2. All branch circuits through one connector?


 
No (Plastic snap in bushings) and yes.

It's allowed by local ammendments since forever. It's _probably _the same in the entire SW region.

In Easten regions where panels and cables are usually exposed in basements, the connector rule makes sense. Out here, with exterior panels and concealed cables, we make adjustments.

There is no practical way to get the cables into the back of an exterior service and use connectors. In framed structures, the cables are secured/staples as the exit the panel. In block structures they generally drop down a cell and are pretty much secured by the forces of nature (friction).


Trying to anticipate the next question, as far as bundling, it doesn't cause problems....ever. I've pulled off *hundreds* of panels and have not seen one single issue from _bundling_.




> Yes, we know already....Don't even go there, don't waste your time...Its accepted here and where he lives....next..


If you learn something, it's not a waste of time :thumbsup:


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## electures (Oct 23, 2008)

NolaTigaBait said:


> :laughing:...Yes, I live in Hack City


Is it really that bad??


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## Dennis Alwon (May 9, 2009)

NolaTigaBait said:


> I dont think its clear at all. If it was, there wouldn't be any confusion.


But that doesn't change the fact that I think it is clear, does it? :thumbup:

If you read the article in 2008 it is spelled out pretty well but I admit it takes reading a few times. Every code change there seems to be proposals on this. 

Why, for instance, if I add an a/c disconnect to the outside disco does that make the feeder have to comply with 310.16. We all know it lessens the load to the interior panel but for some reason we need a bigger wire. 

I do understand the reasoning but this scenario that I just presented is one of those case where it makes no sense.


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## tates1882 (Sep 3, 2010)

220/221 said:


> No (Plastic snap in bushings) and yes.
> 
> It's allowed by local ammendments since forever. It's _probably _the same in the entire SW region.
> 
> ...


 
Sure there is put the two screw on the ser first, tighten then pull ser through as you set the service, put on locknut.


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## 220/221 (Sep 25, 2007)

I was speaking more of the bundle of 10 to 15 cables that typically go thru the 2, 2.5" KO to feed the whole house. The bushing is good for those so it's good for the ser. :thumbsup:


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## user4818 (Jan 15, 2009)

220/221 said:


> I was speaking more of the bundle of 10 to 15 cables that typically go thru the 2, 2.5" KO to feed the whole house. The bushing is good for those so it's good for the ser. :thumbsup:



I like the snap-in bushing thingamabob you guys do out there. Makes it nice and simple.


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## Jlarson (Jun 28, 2009)

I know there is no way in hell I'm ever gonna chop a big hole in the side of a house to put a bunch of romex connectors on, the snap in bushing way is the best way to go IMO.


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## rnr electric (Jan 29, 2010)

Dennis Alwon said:


> 4/0 is only legal if the feeder carries the entire load of the service. Once a breaker is added in the exterior panel the 4/0 se cable is no longer compliant because it must follow 310.16


 Dennis: i totally agree with your interpratation of this (310.16). i met with state inspector today for a job and posed this to him, his oppinion was this. "this is a UL rated panelboard for this particular application and if you do not exceed rating at either board, you are compliant!!" ( his words not mine). He simply stated that because they were both fed from same bus bars but not from first to the second brkrs.his annalogy was if you feed two 60 amp subpanels from a 100 amp svc it is your TCL that determines this (?). also this panel is commonly called a 400 amp but it is actually a 320. whats your thoughts


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## Dennis Alwon (May 9, 2009)

I am not sure what the inspectpr stated has anything to do with my statement.

I agree that the TCL is the key not the breaker size. I can actually use a feed thru panel and feed 2,3, or more 200 amp panels as long as the TCL is under 200 amps.

In terms of the 400 amp panel that the op installed I have no issue with the 2 - 200 amp breakers as the panel is listed for that. My issue is with the wire to the sub panel.

The meter is rated 400 amps. it is only rated 320 if there were a continuous load. The same is true of a 200 amp meter. It is rated 200 amps but 160 continuous.


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## 220/221 (Sep 25, 2007)

I got the undergound in Friday. 

This is a relocate/upgrade and I had to intercept the direct buried POCO triplex and the markings were off about six feet.

I _only_ hit the water service, irrigation lines, phone and cable.....and a 16' x 16' concrete slab that was buried beneath 4" of decomposed granite coming into the garage.











Somebody with a jackhammer came by to remove the concrete but for some reason they left this for me to move.


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## 220/221 (Sep 25, 2007)

Got the UG done and backfilled. Got the Utility clearance for temp power.










I know.....My PVC slipped down.


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