# Junction Box



## nkalghatgi (Nov 14, 2013)

I am working on a roadway lighting project. I want to size a junction box which will be embedded in the concrete for the lights on the roadway bridge. I am using a 3" conduit for all the light poles and a 2" conduit from the base of the pole to the luminaire. What should be the size of my junction box ?


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## Dennis Alwon (May 9, 2009)

It depends on whether the pulls are straight or angle pulls.


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## Dennis Alwon (May 9, 2009)

Here are some graphics


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## Dennis Alwon (May 9, 2009)

Here are some more


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## nkalghatgi (Nov 14, 2013)

There will be straight pulls from one pole to the next and angle pull from the base of the pole to the luminaire.


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## Dennis Alwon (May 9, 2009)

nkalghatgi said:


> There will be straight pulls from one pole to the next and angle pull from the base of the pole to the luminaire.


The diagram above should tell you the info-- try and figure it out


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## sbrn33 (Mar 15, 2007)

For something like that an12X12 or 12X18 quazite box will be fine. Might not meet the exact codes though.


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## 360max (Jun 10, 2011)

...keep in mind, the diagrams Dennis posted *are only required if conductors are larger than #4 AWG*


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## 360max (Jun 10, 2011)

Dennis Alwon said:


> It depends on whether the pulls are straight or angle pulls.


...if smaller than #4, the x6 and x8 rules do not apply


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## nkalghatgi (Nov 14, 2013)

Based on above diagrams and considering that my wires are greater than #4AWG, I found out the length should be at least 24" and width should be at least 18". I just need to know whether I am correct.

Thank you everyone for the help.


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## Dennis Alwon (May 9, 2009)

360max said:


> ...if smaller than #4, the x6 and x8 rules do not apply


And do we know the size of the conductors? We have had to pull some large conductors for VD on pole lights.


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## nkalghatgi (Nov 14, 2013)

The wires running from one light pole to the next are #2AWG and from the base of the pole to the luminaire are #10AWG.


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## LGLS (Nov 10, 2007)

nkalghatgi said:


> The wires running from one light pole to the next are #2AWG and from the base of the pole to the luminaire are #10AWG.


Aren't the boxes spec'd by DOT?


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## nkalghatgi (Nov 14, 2013)

MassDOT doesn't specify the sizes


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## LGLS (Nov 10, 2007)

nkalghatgi said:


> MassDOT doesn't specify the sizes


I find that hard to believe. Every city has a standards spec. If it's not project specific then the DOT should have approved manufacturers, typical cut sheets, and guidelines.


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