SER 4/0 service feeder

[WireCop]

First read 338.10 (B)(4) this is for a single family home, the feeder leave a 200 amp OCD at meter, runs through the attic of garage to a 200 amp MLO panel in house. IS the 4/0 SER rated for 200 amps? When run through the insulated attic?

2011 NEC

 

[infinity]

Is the SE cable under the insulation?

 

[augie47]

You have entered an area that has been much debated here on the Forum.
You might gain some insight from the following thread:
http://forums.mikeholt.com/showthread.php?t=114010&page=4&highlight=SE+ampacity
(I found post 40 particularly interesting)

 

[texie]

First read 338.10 (B)(4) this is for a single family home, the feeder leave a 200 amp OCD at meter, runs through the attic of garage to a 200 amp MLO panel in house. IS the 4/0 SER rated for 200 amps? When run through the insulated attic?

2011 NEC

Yes, if it qualifies as carrying the ENTIRE load of the dwelling. Under the 2011 NEC the resi table 310.15(B)(7) makes no other requirements for derating. This has been modified in the 2014 NEC to fix this contradiction.

 

[GoldDigger]

First read 338.10 (B)(4) this is for a single family home, the feeder leave a 200 amp OCD at meter, runs through the attic of garage to a 200 amp MLO panel in house. IS the 4/0 SER rated for 200 amps? When run through the insulated attic?

2011 NEC

Two potential problems that I see, both based on the fact that they are still service conductors until they reach the first disconnect with OCPD, even though you have passed the meter:
1. They run through one building to reach another if it is a detached garage and
2. They run inside the house for some unspecified but large distance before reaching the service disconnect, if it is an attached garage.

Do not forget that whether over or under the insulation, conductors in the attic are inside the building. (See 230.6) [2011]
I suppose you could encase them in concrete, but that seems to be such a waste and may require strengthening the ceiling structure.

 

[infinity]

Two potential problems that I see, both based on the fact that they are still service conductors until they reach the first disconnect with OCPD, even though you have passed the meter:
1. They run through one building to reach another if it is a detached garage and
2. They run inside the house for some unspecified but large distance before reaching the service disconnect, if it is an attached garage.

Do not forget that whether over or under the insulation, conductors in the attic are inside the building. (See 230.6) [2011]
I suppose you could encase them in concrete, but that seems to be such a waste and may require strengthening the ceiling structure.

He did say service feeder and I'm assuming that "OCD" means he has overcurrent protection at the meter.

 

[kbsparky]

He did say service feeder and I'm assuming that "OCD" means he has overcurrent protection at the meter.

Persactly.

I believe that OCD = Over Current Device

Since it carries the entire load of a dwelling (we assume this of course), the existing Code allows a 200 Amp rating.