Derate or more runs

[electricalist]

What are some pro s and cons when deciding to derate to get multiple to a locarion vs just run more smaller conduits with less circuits. . I have seen j men battle witts for hrs just on proper derating. Thanks

 

[infinity]

IMO part of the issue is how hard is it to run the raceway. If there's a rack already there and you're simply throwing conduits on the rack then more raceways with smaller conductors might be more cost effective. On the other hand if the routing of the conduit is difficult a singular larger raceway with larger conductors may be better. For argument's sake what size circuits are we talking about?

 

[iwire]

Don't forget that with 14, 12 & 10s in most cases derating will not be a factor till you exceed 9 current carrying conductors. That being the case multiple runs of 3/4" with under 9 CCCs each is a pretty solid plan.

Of course I would just use MC and be done with it.

 

[electricalist]

Im learning based on 12 & 10 awg. And 9 ccc is what I use as example. That is 9 circuits using tge 3 pole method (fullboatx3) 4 cicuits wirh single pole method 1 ungrounded 1 neutral

 

[iwire]

Im learning based on 12 & 10 awg. And 9 ccc is what I use as example. That is 9 circuits using tge 3 pole method (fullboatx3) 4 cicuits wirh single pole method 1 ungrounded 1 neutral

It could be four - 2-wire circuits as well.

Keep in mind that sometimes a 'full boat' would have to be counted as four current carrying conductors.

2011 NEC 310.15(B)(5)(c)

(c) On a 4-wire, 3-phase wye circuit where the major
portion of the load consists of nonlinear loads, harmonic currents
are present in the neutral conductor; the neutral conductor
shall therefore be considered a current-carrying conductor.

 

[electricalist]

For arguments sake. This is an amazing web site. Honestly I was some days I would ask my self how many jack a-- stuck up know it all electrician s am I gonna have to deal with til I get more knowledge. On my X forum site the general answer to these type questions was if u dont know then u have no buisness asking. All the mods would help.

 

[electricalist]

It could be four - 2-wire circuits as well.

Keep in mind that sometimes a 'full boat' would have to be counted as four current carrying conductors.

2011 NEC 310.15(B)(5)(c)

Just to keep it simple for and the electrician after me I was thinking a full boat like black (a) phase for x amount of office computer outlets maybe 2 or 4 then b phase 6 office outlets. .- 2 offices c phase same as b . Im thinking that will take care of 4 offices . A phase can be put on battery back up right at the panel . A being soft load comp circuits B /C Having room to add

 

[J.P.]

Anytime I have to think about derating I just run more conduit or mc.
So far ( for me ) derating has never been worth the hassle of running larger wire than planned or larger pipe.

it has been my experience just to run multiple conduits or mc. Derating so you can only run one larger pipe never seems worth it once you actually figure the wire size you have to use to carry the load. Then of course you need to use larger conduit because the wire is larger.....Oh now you can fit more in, the derate percentage just went up...I'm not pulling #6 for a 20A circuit.


I needed to run 30 120v 20A circuits to a gutter. I ended up using 12/2 mc for simplicities sake. No derating, no conduit fill, no identifying circuits in the pipe.

 

[jumper]

Don't forget that with 14, 12 & 10s in most cases derating will not be a factor till you exceed 9 current carrying conductors. That being the case multiple runs of 3/4" with under 9 CCCs each is a pretty solid plan.

Of course I would just use MC and be done with it.

Im learning based on 12 & 10 awg. And 9 ccc is what I use as example. That is 9 circuits using tge 3 pole method (fullboatx3) 4 cicuits wirh single pole method 1 ungrounded 1 neutral

The "magic rule" of 9 CCCs in a pipe does not work for #10s. 40A x 70% = 28A.

 

[iwire]

The "magic rule" of 9 CCCs in a pipe does not work for #10s. 40A x 70% = 28A.

Hint, sometimes 240.4(B) applies.

 

[jumper]

Hint, sometimes 240.4(B) applies.

Doh!!!!

:slaphead::slaphead::slaphead:

 

[electricalist]

Ty very much to all of you. I hope the vast amount of things I have learned here ofset the amount of time im not working cause I csnt but to take in all the info I can . Atleast im not on the phone doing nithing important.

 

[MasterTheNEC]

Don't forget that with 14, 12 & 10s in most cases derating will not be a factor till you exceed 9 current carrying conductors. That being the case multiple runs of 3/4" with under 9 CCCs each is a pretty solid plan.

Of course I would just use MC and be done with it.

And I love your way of thinking....