Hello, I have a motel that has 18 rooms and will be converted into 14 apartments. It has a 1200 amp 120/240 3/phase service currently but the poco is going to change to to 120/208 system. According to my load calculations I can get by with around 400 amps. Each apartment is approximately 650 sq ft and has a water heater, mini-spit system for heat/air, range, dishwasher, microwave. I'm wanting to install (2) 400amp panels and feed 7 apartments off each panel. The longest distance is around 160 feet. My question is, can the feeders to each apartment be #2 aluminum ser or should they be 1/0 ser? According to my calculation each apartment with the optional method would be around 91amps. I know there is an 83 percent rule which looks like it should apply to feeders also. I'll have 100 amp panels in each apartment. I also have 5 dryers and washers that I'll split between the 2 panels.
Apartments
- Thread starter frofro19
- Start date
- Status
- Location
- Connecticut
- Occupation
- Engineer
#2 Al would be sufficient for a 100A apartment feeder.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
No meters for these apartments?
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
It may depend on the code cycle and how they are installed. For a few code cycles, they required a lower temperature rating, then changed it to only if installed in insulation, then went back to the way it was.
There's a CT cabinet on the outside of the building and it feeds to the 1200 amp main disconnect in the mechanical room. The owner is paying all utilities so only one meter.
That's no longer allowed in many states due to the energy codes.
Are you referring to the poco? If so, I've already met with them and the AHJ and they are ok with it.
MyCleveland
Senior Member
- Location
- Cleveland, Ohio
Steve
Could you cite an example with a code reference ?
The International Energy Conservation Code (IECC) normally pronounced "Ick" which often seems fitting.
You can check local/state adoption here:
www.energycodes.gov
I'm not sure if you have a commercial or residential building. The requirements may differ, and here in Illinois, they have some additional rules about which buildings are commercial or residential.
You can check local/state adoption here:
Status of State Energy Code Adoption | Building Energy Codes Program
I'm not sure if you have a commercial or residential building. The requirements may differ, and here in Illinois, they have some additional rules about which buildings are commercial or residential.
- Location
- Connecticut
- Occupation
- Engineer
I don't believe that the IECC prevents a single utility meter so that the owner is paying all of the utility costs.
The IECC may require that you also provide a submeter for each dwelling unit, but that doesn't have to be a utility or revenue meter.
That does look like it would meet the code, but I have had AHJ's that read more into it than it actually says.
Does the AHJ have the final say?
According to what I am reading, the 83 percent rule can be applied (310.15(B)(1)(3)
Which allows #2 SER from the 75 degree column of 90 amps if not run in insulation and the 60 degree column would have to be used if the conductors are run through insulation for 10 feet or 10 % whichever is less which would be #1 SER in the 60 degree column of 85 amps. This sound correct? I'll be running the feeders through the crawl space but if they are run in insulation I'll probably go with 1/0 ser as my supplier doesn't carry the #1 ser.
Which allows #2 SER from the 75 degree column of 90 amps if not run in insulation and the 60 degree column would have to be used if the conductors are run through insulation for 10 feet or 10 % whichever is less which would be #1 SER in the 60 degree column of 85 amps. This sound correct? I'll be running the feeders through the crawl space but if they are run in insulation I'll probably go with 1/0 ser as my supplier doesn't carry the #1 ser.
- Status