SERVICE WIRE SIZE
- Thread starter domnic
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Did you perform a load calculation?
- Location
- Bremerton, Washington
Not enough information.
How many meters?
Or is it a CT service?
What is the calculated load?
How many meters?
Or is it a CT service?
What is the calculated load?
one meter base two meters .
- Location
- Bremerton, Washington
So you want the size on the line side of the meters?
Can you post a sketch?
Can you post a sketch?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Sounds like a single set of service entrance condcutors to two meters and then to a 100 and 200 amp service disconnect. You'll need a load calculation to determine the conductor size ahead of the meters. I guess without one you can just size them for 300 amps.
timmermeier
Member
- Location
- alton il
- Occupation
- electrician
if i size them for 300 amps 250 KCM ??????????????????????????
For a commercial building, not unless you can show a calculated load of 255 amps or less.
Without a calculated load it's going to be 350kcmil cu
For many years our local Ultility company printed the "Blue Book " a 5 by 7" maybe 120 page book with great illustrations and tables. Have seen as many as five 100 amp services for small buildings be only feed with 4/0 aluminum SEU cable that is only rated for 200 amps in residential setting. Going by thier . . table 6.7.2 it states for multiple Residential installations four meters require a minimum of 4/0 aluminum and six require a minimum of 300 Aluminum MCM . Does not make sense that this table does not state if that small wire was for 100 or 200 amp services. A few times I installed a 200 amp service for a store on the first floor and a 100 amp service for a two bedroom apartment on the second floor and ran service conductor sized for 250 amps and always passed inspection. All had natural gas for furnace & appliances. The Blue Book that I mentioned is now only available over the Exelon/PECO web site.
- Location
- Bremerton, Washington
If you install 300 kcml you have a 255 amp service. That may be ok for now, but future tenants could add more load. In WA, we have to install an engraved label stating the service size is 255 amps
Agree with you 100%. Now with some states are going to ban natural gas in new homes then down the road make existing homes loose thier natural gas and some homes required two EV chargers wonder if some of larger all electric homes would require a minimum of a 300 amp service if they do not have load management system &/or PV with possible battery storage. I have installed just a two hundred amp three phase service in machine shops & plastic injection start ups where money was tight and tried to talk them into getting a 400 amp service. Had to come back in a few years to upgrade the service.