"I-Line" bus arrangements

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ibew441dc

ibew441dc

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408.3(E) is pretty clear in pointing out phase arrangements. Front to back, top to bottom, left to right.

Although I do not see this as a violation , If a set of bus bars are arranged front to back (vertically) . The breakers on the right would be arranged
A
B
C

the breakers on the right are
C
B
A

Personnaly I do not like this style of switchboard or panelboard. Although the buses are arranged in a code compliant manner , I am not sure if I if the right side is possibly a violation.

C
B
A

Does this arrangement violate 408.3(E) At first I thought it did, but now I'm not sure.

Any feedback would be great.

ibew441dc
 
LarryFine said:
Why do I not understand? :-?
Click to expand...
It is not a violation of 408.3(E), which is a requirement for the phase arrangement of buses only. It does not apply to circuit breaker terminals.

I-LineBus.jpg
 
LarryFine said:
Why do I not understand? :-?
Click to expand...

I-Line panel boards are different than any other panel boards I have seen. They are typically used as distribution panels.

I like them, they have a lot of nice features.

For one you can install a 800 amp breaker in the same spaces as a few single pole 20s without having to change any bus hardware.

Smart$ posted a great picture of the stacked bus arraignment and you can see how the breakers plug in.

The down side of this arrangement is that on the left side the breaker terminals are from top to bottom A B C, put that breaker on the right side and the terminals run C B A from top to bottom. By the way the terminals are marked with the phase letters to make this clear.

Another issue is the position in the panel does not determine the phase the breaker is connected to. Circuit 1 can be A, B or C dependent on the breaker itself.

When you order a single pole breaker you must specify if you want it phase A, B or C. If you want a two pole you must specify A-B, A-C or B-C phases.
 
I-Line

I-Line

LarryFine said:
Great pic .
Click to expand...

Yes. But he's holding the breaker incorrectly. :)
You must:
(a) work the panel "hot"
(b) reset ther breaker before installing
(c) use the lugs as guides, placing your fingers in them as you would a bowling ball.

Sorry, just a quick trip down nostalgia lane. One of life's "learning experiences"
 
only "smarts" briefly

only "smarts" briefly

"Nothing is foolproof to a sufficiently talented fool. "

raises hand!
 
Smart$,

Thanks for the great picture.

I have been working in the electrical trade for about 7 years , (mostly new construction, commercial and industrial).

Recently I was schooling a young apprentice on phase arrangement , top to bottom , front to back, left to right. The apprentice then challenged my logic by pointing out the labels on the breakers appearing to be up-side-down.

Not having any experience with this I-Line type panelboard I did what any competent electrician would do . I expained that the breaker manufacture always labels from left to right and instucted him to ignore the letters and make up the panel
A
B
C
on both sides.

Later that day I became curious about this configuration, so I disected a panelboard , to find that whoops! the labels were right . At first glance , My thought was VIOLATION of 408.3(E) . After reading the section over and over again ( I thought the more I read it , the words would morph into what I thought it said:rolleyes: ) I realized I was totally wrong.

Good thing I caught it when I did. We are not close to energizing and have many more of these I-Lines to go. The result of my original assumption could have been terrible.

I originally stated that I didn't like this set up , but I am slowly changing my opinion, I see many advantages.

I do think that Square D should make an obvious warning on there equipment.
After consulting many of my mentors about this I have come to the conclusion that I am not the only one that has made this mistake.

This was a great lesson learned for me , that I havn't seen it all. ( keeps me the right size)

thanks ,

Ibew441dc
 
Square D makes offers all I-Line breakers with a phase arrangement so that this "phasing" problem goes away.

Simply order the breaker with the suffix CBA (i.e. FA34100CBA).
 
jim dungar said:
Square D makes offers all I-Line breakers with a phase arrangement so that this "phasing" problem goes away.

Simply order the breaker with the suffix CBA (i.e. FA34100CBA).
Click to expand...


I'm assuming that's a 3 pole breaker with the terminals reversed top to bottom?

I also like specifying the Iline panels. But I just realized, a lot of the time I have spent on Iline panel schedules putting 2 pole breakers in certain spaces so they wind up on certain phases was all for not. I didn't realize it is the breaker part number that determines the phasing.

Also, if you order Ilines with the front doors, I don't like the latches or locks. A lot of times you have to slam the door and hammer the latches to get the door open and closed. Then you are lucky if the lock will work. Does anyone else think the doors and locks could use some improvement?
 
steve66 said:
I'm assuming that's a 3 pole breaker with the terminals reversed top to bottom?
Click to expand...

They offer these "reversed" load connections on both 2 pole and 3 pole designs.

This phasing issue is very rarely a problem, because the normal breakers have phasing identification right at the lugs. Square D has been making these reversed breakers since at least 1978, but relatively few people use them. I think the only times I have needed them have been on government projects.
 
steve66 said:
Does anyone else think the doors and locks could use some improvement?
Click to expand...

I use SQ D I-Line Nema 3R/12 panels at marinas. These have the hinged cover, a door handle in the middle (lockable) and a couple of 1/4-turn screws that operate a latch (one above the handle and another below the handle) to keep the door closed. I had an interesting experience last week. We hung the panels, installed the interiors, took the trim pieces and stuffed them into the sides and bottom of the panel. When we went to open the door the next day, I couldn't get the lower 1/4-turn screw to turn put about 5 degrees. I finally realized that the trim pieces that I just stuffed into the bottom of the panel were wedged under the latch on the bottom 1/4-turn screw. I tried banging on the door while turning the screw but it would not budge. I tried banging on the door then turning the screw, still no luck. I had a fiberglass ground probe that I was able to get in-between the door and can from (had to pry on the door) the bottom and push the trim pieces back, and then get the screw to turn. Whew, I was getting panicky, because I did not want to take that 500 lb. panel (it at least feels like 500 lbs.) off the wall.
 
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