Table 310.15(B)(2)(a)

[viclibo]

I have another situation. I have an existing residential 200 A service with a 2 inch schedule 80 going down to a LB and into the crawl space. There are probably 30 plus circuits going down through this chase into the crawl space. My concern are the number of current carrying conductors in this raceway and following this table. Any thought and feedback? Thanks in advance!!!!!!!!!!!!!!

 

[Twoskinsoneman]

I have another situation. I have an existing residential 200 A service with a 2 inch schedule 80 going down to a LB and into the crawl space. There are probably 30 plus circuits going down through this chase into the crawl space. My concern are the number of current carrying conductors in this raceway and following this table. Any thought and feedback? Thanks in advance!!!!!!!!!!!!!!

woah... wrong table sorry

Anyway since I started posting something wrong I'll go ahead and put something useful out there. The installer would of had to derate based on the number of CCC.
Based on 30 plus circuits in one raceway your looking at wow...35%

There are lots of factors that need to be known.... length of shed 80, type of wire, gage of wires, the more info the better.

 

[480sparky]

I have another situation. I have an existing residential 200 A service with a 2 inch schedule 80 going down to a LB and into the crawl space. There are probably 30 plus circuits going down through this chase into the crawl space. My concern are the number of current carrying conductors in this raceway and following this table. Any thought and feedback? Thanks in advance!!!!!!!!!!!!!!

What size of wires? What size are the OCDs for these wires? How many are truly CCCs?

 

[viclibo]

different size wires. Better to start figuring on circuit sizes. I have a 50 A, 2- 30 A. 15- 15a and 15 20 a.
Also I recently read that the breakers are only rated to 80% so after I derate I derate again to compensate for the breaker. I also use the 75 degree column from Table 310.16 because the panels and receptacles are rated for 75 degrees only.

 

[480sparky]

different size wires. Better to start figuring on circuit sizes. I have a 50 A, 2- 30 A. 15- 15a and 15 20 a.
Also I recently read that the breakers are only rated to 80% so after I derate I derate again to compensate for the breaker. I also use the 75 degree column from Table 310.16 because the panels and receptacles are rated for 75 degrees only.

Breakers are rated for full load. A 20a breaker can be loaded to 20 amps. Derating for raceway fill and/or continuous loads only applies to conductors.

Which column you use for derating depends on the conductor used. The terminals are not an issue.

 

[raider1]

Breakers are rated for full load. A 20a breaker can be loaded to 20 amps.

The standard breakers are rated at full load for non-continious loads, and 80% for continious loads. That is the reason that you must take 125% of the continious load when sizing branch circuit and feeders. Take a look at exception #1 to 210.19(A)(1) and 215.2(A)(1).

Chris