multifamily dwelling

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warriorelectrician

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I am bidding on some 6plex units and have a few questions. First is the service, the specs. call for two parallel runs of 4-0 with 3-0 neutral on a 350 amp main breaker all grouped together. Now I now you can do this but where does it say you can group more than 6? My next question is the specs are calling to run #2 alum SER to each unit on a 100amp breaker from the service. I have failed this on inspection before because this does not follow under the 310.15 code because he considered the service entrance where the 100amp main breaker was (at the service) outside. Therefore I had to follow 310.16 and run 1-0 ser. Oh yeah 60 degree or 75 degree on the SER wire.
Now I know this could be considered using the entire load per unit but each inspector has his own interpretion. What is yours
 
I assume they are meaning grouped together at the service. Running two-two inch pipes would be fine for the parallel runs. As far as the #2 ser can't you run the 100 amp circuit off of the individual units panel? The 60 degree column applies after you enter the building I believe.

Good luck
 
"warriorelectrician", is this a commercial or residential project your biding on?

#2 SE-R, when used for residential, is allowed to be fuse at 100 amp. at the
service. Table 310.15(B)(6) ARTICLE 310.15(6)

#2 SE-R in comerical use, should be fuse at 90 amps., that my opinion.

So 1/0 SE-R would be used in a commercial application.
 
warriorelectrician said:
I am bidding on some 6plex units and have a few questions. First is the service, the specs. call for two parallel runs of 4-0 with 3-0 neutral on a 350 amp main breaker all grouped together. Now I now you can do this but where does it say you can group more than 6? My next question is the specs are calling to run #2 alum SER to each unit on a 100amp breaker from the service. I have failed this on inspection before because this does not follow under the 310.15 code because he considered the service entrance where the 100amp main breaker was (at the service) outside. Therefore I had to follow 310.16 and run 1-0 ser. Oh yeah 60 degree or 75 degree on the SER wire.
Now I know this could be considered using the entire load per unit but each inspector has his own interpretion. What is yours
Click to expand...

You said it is six plex so unless it needs a house meter what is problem ?
 
Your new here so give you a welcome and suggestion, we need to know where your located.
You left out a lot of needed info like heat / ac /gas appliances /laundry, house meter. We like to help but really need details.
 
I am in the state of washington. The job is residential and I agree about table 310.15.6 #2 is good but when do you have to rate conductors at 60 degrees. Would you have to rate the feeder at 60 degrees, my opinion is no because each feeder would carry 100 % of the load to each unit. It does need a house panel that is what I'm confused about. Can you group 7 disconnects together 6 100amp for each unit, 1 125 amp for house panel?
 
warriorelectrician said:
I am in the state of washington. The job is residential and I agree about table 310.15.6 #2 is good but when do you have to rate conductors at 60 degrees. Would you have to rate the feeder at 60 degrees, my opinion is no because each feeder would carry 100 % of the load to each unit. It does need a house panel that is what I'm confused about. Can you group 7 disconnects together 6 100amp for each unit, 1 125 amp for house panel?
Click to expand...

Main disconnect for the entire service. Then you can group all the meters with their respective main breakers down stream from there.
 
warriorelectrician said:
I am in the state of washington. The job is residential and I agree about table 310.15.6 #2 is good but when do you have to rate conductors at 60 degrees. Would you have to rate the feeder at 60 degrees, my opinion is no because each feeder would carry 100 % of the load to each unit. It does need a house panel that is what I'm confused about. Can you group 7 disconnects together 6 100amp for each unit, 1 125 amp for house panel?
Click to expand...

230.40 ex. #5 says you can have another service drop or lateral but 230.71 says only six allowed at one location. How far apart would be considered another location? I'm sorry but I don't know that answer.
 
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