# 150 amp feed to a 200 amp panel



## scram (May 3, 2017)

I would like to know if there is a code preventing me to connect a 200 amp panel to a 150 amp breaker and 2/0 copper wire


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## frenchelectrican (Mar 15, 2007)

scram said:


> I would like to know if there is a code preventing me to connect a 200 amp panel to a 150 amp breaker and 2/0 copper wire


Techally ., no it a code issue but the issue is if you have 200 amp panel .,

the conventail 2 pole breaker the largest one you will find is 125 amp the tops but once you get over that size you will go with *four*.,, yes four pole breaker. ( basied on single phase circuits ) 

Be aware some panels will NOT take 150 amp breaker so check it ahead of time. 

And it is not a common item in stock so you will have to order it ahead of time and 4 pole breaker is not cheap by the way.

And the termation on four pole breakers are in angle so watch out on that when you run those larger conductors.


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## Kevin (Feb 14, 2017)

There's no restrictions that I know of on an OCPD being smaller than the load. It's only to protect the wire really. You can put the 200 amp panel on a 150 amp breaker. I have no clue about the 2/0 copper apmacity though. Good luck!

Sent from my SM-G920W8 using Tapatalk


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## frenchelectrican (Mar 15, 2007)

Kevin_Essiambre said:


> There's no restrictions that I know of on an OCPD being smaller than the load. It's only to protect the wire really. You can put the 200 amp panel on a 150 amp breaker. I have no clue about the 2/0 copper apmacity though. Good luck!
> 
> Sent from my SM-G920W8 using Tapatalk


the 2/0 copper THHN ampcapitcy is about 170 amp but I will verify with my chart to make sure. 

And with this large a conductor will use 75°C table not the 60°C tables.


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## scram (May 3, 2017)

why cant I use the 90 degree table?


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## frenchelectrican (Mar 15, 2007)

scram said:


> why cant I use the 90 degree table?


very simple .,, the 90°C table is for derating purpose only.

The keyword is termation tempture that what really count there due some are rated for 75°C and some are at 60°C. very few and I mean very few termations are rated much higher but genrally not covered in common discussion here. 

If those termation devices are marked on 90°C then you can use 90°C table easy.


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## telsa (May 22, 2015)

scram said:


> I would like to know if there is a code preventing me to connect a 200 amp panel to a 150 amp breaker and 2/0 copper wire


Such schemes are ten-a-penny in three-phase world.


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## backstay (Feb 3, 2011)

Kevin_Essiambre said:


> There's no restrictions that I know of on an OCPD being smaller than the load. It's only to protect the wire really. You can put the 200 amp panel on a 150 amp breaker. I have no clue about the 2/0 copper apmacity though. Good luck!
> 
> Sent from my SM-G920W8 using Tapatalk


The 200 amp panel isn't a load. And yes you can feed the 200 amp panel with 150 amp breaker. 2/0 copper is good to 175 amps.


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