Conduits Entering Switchboards

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mstrlucky74

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Location
NJ
This switchboard section was revised to add the feeder tags “1200”& “3000” which is 3 & 5 sets of 4”. These conduits would never enterthe sides, sort of like nipples, would they? Kind of how it's depicted. Or would they leave/enter each sectionfrom the top. Makes a big footage difference……how would you ever really knowduring the estimating phase. Experience I assume. Thanks.
 

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liquidtite

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Location
Ny
I think that's just how they drew it up not for you to enter in sides.

You could enter into switch board from top or stub into bottoms.

i never really seen switch board having conduits enter sides I don't think it would look good,

and then you could never add anouther section on in future.
 
infinity

infinity

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Location
New Jersey
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Is the 750 KVA transformer part of the switchboard or are these all separate components/sections? And the 500 kcmil to building steel/water pipe is a waste of someones money.
 
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mstrlucky74

Senior Member
Location
NJ
infinity said:
Is the 750 KVA transformer part of the switchboard or are these all separate components/sections? And the 500 kcmil to building steel/water pipe is a waste of someones money.
Click to expand...

Well switchboards that size always come as separate sections then get bolted together. In this case I'm not sure. I guess if they are bolted together they could still run conduits as shown but like Joe mentioned it could be bus tied together.....but then why show the conduits? A revision added those conduit tags and separated the xfrmr section as shown on the riser which is making me think...why:?
 
infinity

infinity

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mstrlucky74 said:
Why the 500mcm a waste. Way oversized I'm thinking?
Click to expand...

#3/0 is the largest size required but if the designer gets all warm and fuzzy using a 500 kcmil so be it.

Regarding the step-up transformer, since the drawing indicates separate raceways I would assume that the 750 KVA is not integral to the switchboard. If it's installed between the two sections then I would guess that short pieces of FMC could be used between the transformer and the high and low voltage sections.
 
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mstrlucky74

Senior Member
Location
NJ
infinity said:
#3/0 is the largest size required but if the designer gets all warm and fuzzy using a 500 kcmil so be it.

Regarding the step-up transformer, since the drawing indicates separate raceways I would assume that the 750 KVA is not integral to the switchboard. If it's installed between the two sections then I would guess that short pieces of FMC could be used between the transformer and the high and low voltage sections.
Click to expand...

As always, thanks.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
Where do you see conduit tags?

You gave us a "part of the picture", not the "whole picture". Interpretation: part of the electrical plans without symbol legend and notes involved. Without those all I see is a revision cloud labeled "triangle 2". Note there is another much smaller one to the right. Without the former drawing and any pertinent notes, I have no idea what got changed (revised).

All I see with what I assume you mean conduit tags are a couple leaders with 1200 and 3000 in an oval callout symbol... and the 1200 callout is subnoted 25. To me these are feeder (wire or bus) ampacity values. Nothing about 'em says conduit. No matter what, if these are truly physically separated switchgear sections, to run conduit between them is ludicrous. Worst cases scenario, wireway. For all I know from here, it can be bus duct.
 
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mstrlucky74

Senior Member
Location
NJ
Smart $ said:
Where do you see conduit tags?

You gave us a "part of the picture", not the "whole picture". Interpretation: part of the electrical plans without symbol legend and notes involved. Without those all I see is a revision cloud labeled "triangle 2". Note there is another much smaller one to the right. Without the former drawing and any pertinent notes, I have no idea what got changed (revised).

All I see with what I assume you mean conduit tags are a couple leaders with 1200 and 3000 in an oval callout symbol... and the 1200 callout is subnoted 25. To me these are feeder (wire or bus) ampacity values. Nothing about 'em says conduit. No matter what, if these are truly physically separated switchgear sections, to run conduit between them is ludicrous. Worst cases scenario, wireway. For all I know from here, it can be bus duct.
Click to expand...


Theres a a separate legend that has the 1200 and 3000 with the associated conduit and wore size.

so what changed is now they show the xfrmr separated from the other two sections .....before they were butted together and they added the feeder tags 1200 and 3000.
 
infinity

infinity

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mstrlucky74 said:
Theres a a separate legend that has the 1200 and 3000 with the associated conduit and wore size.

so what changed is now they show the xfrmr separated from the other two sections .....before they were butted together and they added the feeder tags 1200 and 3000.
Click to expand...

The original drawing was obviously incorrect because you had a 208Y/120 volt section and a 480Y/277 volt section. Now the transformer gets you from 208 to 480 volts.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
mstrlucky74 said:
Theres a a separate legend that has the 1200 and 3000 with the associated conduit and wore size.

so what changed is now they show the xfrmr separated from the other two sections .....before they were butted together and they added the feeder tags 1200 and 3000.
Click to expand...
I wonder why the sections do not abut. Probably has to do with proper ventilation, perhaps transformer heat not contributing to adjacent section temperature rise. Still, [straght] conduits between switchgear sections is DEFINITELY not the way to go.
 
dkidd

dkidd

Senior Member
Location
here
Occupation
PE
Smart $ said:
I wonder why the sections do not abut. Probably has to do with proper ventilation, perhaps transformer heat not contributing to adjacent section temperature rise. Still, [straght] conduits between switchgear sections is DEFINITELY not the way to go.
Click to expand...

The transformer is not switchgear construction. It is a standard Square D dry type.
 
Smart $

Smart $

Esteemed Member
Location
Ohio
dkidd said:
The transformer is not switchgear construction. It is a standard Square D dry type.
Click to expand...
That's the problem with these particular drawings. Look like a riser diagram but really nothing more than a one-line. A "wannabe".
 
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