Grouping of disconnects for service

[ikeberg]

So I have a addition to a house I am doing and because everything is going to be electric and no gas and what's existing on the original house, the existing 200a service wont cut it so were adding a new 150a panel in the addition. Installing a new meter for the 350A service. Since both panels are in different sections of the house, I need to have a disconnecting means in one central location ideally within 10' of eachother. What I am wondering is if it is ok to put the service disconnect for the 150a in the bedroom right next to the existing 200 and that is where the serve penetrates the building? Since that disconnect has to be an enclosed cb or fused disconnect( which aren't cheap) I will now eliminate having to put two expensive disconnects outside and I wont have to seperate the grounds and neutrals in the 200a existing service. Any ideas and insight is appreciated

Also where I am trying to put the disconnect is about 40 feet or so from the 150a panel and I am trying to utilize the 50' of 2/0 2 conductor al se cable I have, but I still need one more insulated cable. Is there a cable that is approved to be pulled through an attick with the se cable instead of buying se cable with 3 insulated conductors. I know I could pipe it in 2", but that's a pita since there isn't much room above the panel to get it down there. I couldn't get a hold of an inspector today, but I've never heard of a cable that is approved for that or see anything in the code about one. Thanks

 

[Dennis Alwon]

All conductors must be in the same raceway or cable assembly so you need to buy the appropriate cable.

Also if the 200 amp panel inside the house is a service disconnect then the 150 amp must be grouped with it--- it sounds like that is what you are doing. Yes?

 

[augie47]

I agree with Dennis. You have Code issues with each scenario. 230.72 requires the service disconnects be grouped together and 300.3 requires the conductors be contained in the same raceway, cable, etc.

 

[kwired]

Are you adding enough load that 200 amps is not enough or is the existing 200 just out of unused spaces?

Services with multiple disconnects must have the disconnects grouped together.

All conductors including equipment grounding conductor of a circuit must be within the same raceway or cable.

 

[ikeberg]

Ya I know they have to be grouped together. Originally I had planned on doing two enclosed circuit breakers outside by the meter but what I'm planning now is putting one enclosed 150a CB in the room by the 200a main breaker panel. That will allow me to not have to separate the grounds and neutrals in the 200 and there will be a disconnecting means for both in one location. I just want to make sure that would be acceptable.

 

[infinity]

Sounds like you need to buy some SER cable.

 

[ikeberg]

It wasnt for panel spaces, its for calculated load. The addition plus the the house is 3600 ft. Plus electric stoves in both, electric heat in the addition, plans for power out to the garage, etc. There's no gas out there so everything is electric except oil heat in existing.

 

[augie47]

Acceptable.
You may need to address your grounding electode conductor size, locations, etc.
It kinda looks like you are stuck with conduit or a 4 wire SER cable for your 150 amp panel.
You mentioned 2/0 AL. Note, depending on how your AHJ views the NEC, if that cable is installed inside, the ampacity could be viewed as 115 amps.
(338.10/334.80).
Locally for that install you would need a 4/0 AL SER.

 

[Little Bill]

Acceptable.
You may need to address your grounding electode conductor size, locations, etc.
It kinda looks like you are stuck with conduit or a 4 wire SER cable for your 150 amp panel.
You mentioned 2/0 AL. Note, depending on how your AHJ views the NEC, if that cable is installed inside, the ampacity could be viewed as 115 amps.
(338.10/334.80).
Locally for that install you would need a 4/0 AL SER.

Gus, Is the SER cable allowed in attics here (locally)? In your area, what is the distance inside that is allowed to a disco./panel if there is not one outside?

 

[infinity]

Gus, Is the SER cable allowed in attics here (locally)? In your area, what is the distance inside that is allowed to a disco./panel if there is not one outside?

I think that the assumption is that when using SER the OCPD is outside adjacent to the meter so the SER can run for an unlimited length within the structure.

 

[augie47]

Gus, Is the SER cable allowed in attics here (locally)? In your area, what is the distance inside that is allowed to a disco./panel if there is not one outside?

Other than NEC restrictions, TN has restrictions on installing SE on exterior walls of metal or masonry. Beyond that there are no restrictions. Unfortunately, 338.10 & 334.80/310/15 are addressed differently by local AHJs.
230.70(A)(1) enforcement also varies slightly but is normally held to 3ft or 5 ft maximum interior run unprotected.

 

[ikeberg]

Thanks for the info.
Now augie47, you mentioned to address my grounding electrode. I'm assuming you were saying that because if my local AHJ required me to run 4/0 since I might run it in the attic, I would then have to make my grounding electrode a 4 copper or 2 aluminum, however if I run 2/0 #6 copper is acceptable. I'm going the route of 2" pvc outside underground with 2/0 al and 2 ground rods with #6 copper since there is no other electrode available, or now that I'm looking at 250.64 (D), should I have to tap off the 200A electrode, which should be a #2(depending on what type of electrode they're using). Sound correct?