# 460 3 phase & 110 single phase in 10*12*8 junction box is it legal?



## 480sparky (Sep 20, 2007)

300.3 (c).


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## JohnR (Apr 12, 2010)

What he said , unless it is life safety. 517.30 (C)(1)


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## Calectrical (Oct 19, 2010)

Ok what about single phase and 3 phase in the same j-box or conduit.?


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## jwjrw (Jan 14, 2010)

Calectrical said:


> Ok what about single phase and 3 phase in the same j-box or conduit.?



Yep. Sure is.


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## mattsilkwood (Sep 21, 2008)

Calectrical said:


> Ok what about single phase and 3 phase in the same j-box or conduit.?


 Maybe. It all depends on the insulation. Most likely you're ok, it's probably 600v insulation.


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## McClary’s Electrical (Feb 21, 2009)

mattsilkwood said:


> Maybe. It all depends on the insulation. Most likely you're ok, it's probably 600v insulation.


 

This answer is confusing. 
Show me an instance that 2 single phase circuits in a box would be fine, and by removing one of those circuits , and replacing it with a three phase circuit, you say I now need special insulation?


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## mattsilkwood (Sep 21, 2008)

mcclary's electrical said:


> This answer is confusing.
> Show me an instance that 2 single phase circuits in a box would be fine, and by removing one of those circuits , and replacing it with a three phase circuit, you say I now need special insulation?


 300v SJ cord.


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## McClary’s Electrical (Feb 21, 2009)

mattsilkwood said:


> 300v SJ cord.


 

Ahhhh, yes. Couldn't think of an instance to fit your statement. Good catch.


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## Calectrical (Oct 19, 2010)

jwjrw said:


> Yep. Sure is.


 what article is this under?


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## ColoradoMaster3768 (Jan 16, 2010)

2008 nec: 300.3 (c) (1)


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## torito33 (Oct 29, 2010)

Let us not forget 210.5 C and 200.6 D when installing conductors of different systems.


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