Panelboards 408.36

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MasterTheNEC said:
Why not download the image and zoom in....I just snapped a picture of it out of the mcgraw-hill handbook...because I knew it had a picture for Don.
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Perhaps because the native resolution of the picture is low enough that the text is not readable and the main breaker wiring including separate feeder breaker direct from input) could be clearer too.
 
steve66 said:
It looks like it fits the rule to me.

I can't really read the example you posted, but the only difference I see is the second breaker in your post supplies a feeder, instead of another bus. I don't see anything in 408.36 Exception 2 that differentiates between the two types of panels shown in this thread.
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That is correct....nothing says the upper left breaker can't feed a second bus structure in the same enclosure which is quite common in commercial applications....but Ex 3 is residential driven.
 
I downloaded it and did zoom in before I requested a better picture. I requested a better picture because I still couldn't read it.
Can you provide one so that I can read what it says? I cant tell what is tied to the line between the 2 breakers for one thing.....
Thanks,
 
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boptrop said:
I downloaded it and did zoom in before I requested a better picture. I requested a better picture because I still couldn't read it.
Can you provide one so that I can read what it says? I cant tell what is tied to the line between the 2 breakers for one thing.....
Thanks,
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Im trying fella...lol....let me try again...lol

So as you see it is not really a SPLIT-BUS design.......but each circuit breaker could protect 42 ckts each...either in the same enclosure or a totally separate load.
 

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If its a BMP you may need to change it to a JPG....lowers the file size.

Sorry, I see the original pict. was a JPG....you will probably have to lower the resolution or compress it.
 
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Yes and thanks! Never seen that setup before. Breaker #2 if feeding other breakers in the same panel would most likely make it a split bus panel ...this would be illegal to arrange, now, I think. Usually when you need breaker #2 it has to be assembled by the factory upon request (as the breaker is large in amperage) and would feed other loads not in the panel and usually the breaker would be feed downstream from breaker #1 I guess both breakers in the pict. cannot be a tap...because (as I recall) a tap has to terminate in 1 set of fuses or CB as I remember. So I don't know where that arrangement would come from unless it is old?
 
GoldDigger said:
Good point about the feeder not being a tap, but as long as there is upstream protection there would not be a tap.
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I think in the picture the bussing between the breakers must be sized for a 200A feeder...If it were rated for less, then, that portion where the feeder terminates and the breaker(s) would be where the tap is.....This set up must be equivalent to the sum of breakers fed off a transformer...in the usual sense.
 
boptrop said:
Yes and thanks! Never seen that setup before. Breaker #2 if feeding other breakers in the same panel would most likely make it a split bus panel ...this would be illegal to arrange, now, I think. Usually when you need breaker #2 it has to be assembled by the factory upon request (as the breaker is large in amperage) and would feed other loads not in the panel and usually the breaker would be feed downstream from breaker #1 I guess both breakers in the pict. cannot be a tap...because (as I recall) a tap has to terminate in 1 set of fuses or CB as I remember. So I don't know where that arrangement would come from unless it is old?
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Only a violation in a residential application.....the example in Ex. 2 is used a lot in a commercial setups.
 
MasterTheNEC said:
That is correct....nothing says the upper left breaker can't feed a second bus structure in the same enclosure which is quite common in commercial applications....but Ex 3 is residential driven.
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That is exactly what the diagram I posted shows. Two main breakers supplying separate bus structures within the same enclosure. How is that not the intent of Exception No. 2?
 
RB1 said:
That is exactly what the diagram I posted shows. Two main breakers supplying separate bus structures within the same enclosure. How is that not the intent of Exception No. 2?
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Actually...I revisited your image and my mistake...for some reason I had in my mind you were showing a (6) CB Split Bus setup as depicted in Ex. 3....forgive my oversight.

Your image would be an example of using Ex. 2....and mine is just another version without showing the second bus systems...both of which are limited to 42 ckts...Sorry Fella...
 
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