Feeders

[imported_Ohm1]

What size wire are you using? And why not any other sizes? Residential only please! Thanks!

[imported_Ron]

You'll need to share some more, to get a valid answer.

[imported_Ohm1]

What size feeders.

[Wgoodrich]

Feeders or branch circuits are sized relative to load being served and ambient conditions that wire is being installed in.

Service conductors sized by demand load set in Chapter 2
Branch circuit conductor sized depending on use of branch circuit, general lighting per TAble 220.3.A, single utilization equipment depending on type of equipment if just dwellings. Heaters would be 80% of wattage rating, cooking equipment again demand load of 220.19, motors per Article 430, detached garage sized per Table 220.3.A and 430 for conductor serving several motors. Many different rules depending on load being served. These are the common rules being used, there are specialty loads with specialty rules found in Chapters 4 through 7 of the NEC.

HOpe this helps

Wg

[imported_Ohm1]

Thank you "WG". This is the area of knowledge that I lack. I can't get a clear answer in the trade. Most are being trained (or not at all) in specific areas of residential, so when it comes to services, or things in realation to calculating, everyone goes dead. I'm trying to teach myself, and being online with you guys/gals will help me. Thanks!

[Wgoodrich]

If your concerns pertain to wiring size for a dwelling's service entrance conductor then you are required by the NEC to perform a demand load calculation to find the MINIMUM service size required to serve that home. The service conductors then must be sized in ampacity to meet or exceed that MINIMUM demand load calculation answer in amps. Then using Table 310.15.B.6 for dwelling service conductor requried ampacity ratings you size your service entrance conductor. Don't forget to add loads of any detached accessory structures fed from that same common dwelling service and add that to your dwelling demand load calculation answer to find total demand load of the entire dwelling estate using that common service of that dwelling. See following article liked;

http://www.homewiringandmore.com/homewiringusa/2002/definitions/demandcalc02/DwlingDmdCalc02.html

If all you are doing is trying to find proper ampacity of a conductor being a normal feeder or branch circuit then start by reading the following ampacity calculation format link that will address ampacity deration required for ambient temperature and more than 3 current carrying conductors in a raceway that are normal concerns of every feeder and branch circuit conductor using Table 310.16 and 240.4 and 110.14.C to size ampacity of branch circuit and feeder conductors.

http://www.homewiringandmore.com/homewiringusa/2002/definitions/ampacity/amp.html

Enjoy reading may help

Wg