200 amp riser

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irelandnewyork

Member
Location
san diego
What is the min size of a ridgid riser for a 200 amp house service, the riser will be used as attachment point for the poco supply. I know the book says 3 x 2 awg are good inside 1.5" but i have a feeling the min is 2". Install is in SO CAL
Thanks for the input
 
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suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
2 AWG is a bit small for a 200A service. For most wires, you can fit three 2/0 in a 1.5" pipe (I believe conduit fill would be the only issue as far as the NEC is concerned). But most utilities seem to want 2" for a 200A service.
 
infinity

infinity

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Location
New Jersey
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Journeyman Electrician
Since you're referring to a mast service where the pipe will be used to support that drop then I would say 2" is the minimum based on what out POCO requires around here. The NEC does not specify a particular size. I've heard some POCO's require 2.5" as a minimum.
 
Steve Beranek

Steve Beranek

Member
Location
St. Louis, Missouri
Sorry, I need to expand on my original post.

Since you need 2/0 wire you would then turn to TABLE C.8(A) for Rigid Metal Conduit fill.

If you are using THWN then you can fit 3 in 1-1/4".

I have been taught to upsize conduit a size so I personally would go with a minimum of 1-1/2" Rigid if not 2" just because I dont want to fight the wire in the pipe.
 
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curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
Steve Beranek said:
Sorry, I need to expand on my original post.

Since you need 2/0 wire you would then turn to TABLE C.8(A) for Rigid Metal Conduit fill.

If you are using THWN then you can fit 3 in 1-1/4".

I have been taught to upsize conduit a size so I personally would go with a minimum of 1-1/2" Rigid if not 2" just because I dont want to fight the wire in the pipe.
Click to expand...

The table you posted is for compact conductors. I have never seen copper compact conductors. You are not going to get 3 standard 2/0 THWN conductors in 1 1/4" rigid.
 
Little Bill

Little Bill

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Location
Tennessee NEC:2017
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Semi-Retired Electrician
I think the answer to your question will be found at your POCO. The ones around here have their own requirements. Most want 2-1/2" rigid for a 200A service.
 
electricguy61

electricguy61

Senior Member
Location
Remotely running business in Bay Area, CA from Med
Most cities in the South San Francisco Bay area require 2" rigid for 200amp, though a few will allow 1 1/2" with 3 4/0 compact aluminum.

On 2 story service changes, I've done 150amp upgrade so I don't have to change out the mast.
A little more expensive material wise (you have to buy a 200amp, and also purchase the replacement 150amp main), but much easier on labor and stucco repairs.
 
kwired

kwired

Electron manager
Location
NE Nebraska
irelandnewyork said:
What is the min size of a ridgid riser for a 200 amp house service, the riser will be used as attachment point for the poco supply. I know the book says 3 x 2 awg are good inside 1.5" but i have a feeling the min is 2". Install is in SO CAL
Thanks for the input
Click to expand...

First thing is it must be able to contain the installed conductors. After that 225.17 and 230.28 both say about the same thing - it shall be of adequate strength to support the overhead conductors or be adequately braced to support the overhead conductors. Neither section gives any details of what is adequate strength, and that will change based on the size and length of the overhead conductors.

3/4 or 1/2 inch mast could be strong enough for some situations with short overhead span of small conductors, but you may not have much luck finding attachment devices for that small of a raceway.

If it is service conductors often POCO will have requirements, if you do not comply with their requirements they do not have to hook you up.
 
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