I am confused about Figure 310-6. It depicts what I consider the grounded neutral current carrying conductor, yet references 250.66, which talks about the grounding electrode conductor. Am I missing something here? Thanks, Sam

Can Table 310.15(B)used for a sub-panel in a single family dwelling?

I really wish the NEC would assume 40C/104F or even 50C/122F as their starting point for all this rather than 30C/86F.

How hot is your attic in the summer? How hot is it in Phoenix? I worked in a factory in MT in the summer and it was well over 100F inside. When the sun beats down, it beats down, even in Alaska.

I sometimes think I'm the only person who temperature de-rates conductors.

Most instruments and machines are stamped for 40-50C max operating temperature and you know the inside will be hotter still.

Yet when you get these little handy wheel chart shortcut toys and such, they have no de-rating.

I had a friend who was chronically late, so we'd just tell him the (fill in blank) started 45 minutes earlier than it really did, and it worked. This is the same deal.

Just woundered if cables built with heat carring materials installed were ever concidered for general use?

THIS MAKE'S THING'S SO MUCH CLEARER THANK,S

On Figure 310-4, aren't the paralleled conductors all supposed to be in the same conduit run? Is the bottom figure correct? I thought I saw this somewhere but can't remember or find it.

From the way I see 310.15(B)(6), the reduced feeder size does not apply in a multifamily situation where the unit feeder is derived from a 120/208 volt, 3-phase service whether the unit feeder is single phase or three phase since the voltage is not 120/240. Is this true?

In a dwelling with romex run through bored holes , does the neutral of a 2 wire 120v circuit count as a current carring conductor or does it fall under 310.15(B)(4)(a).

This is insane this is never enforced anywhere that I know of it was important about 15 yrs ago when the new electronic ballasts were throwing off sick harmonics and proportional heat but nowadays the ees have gotten better with power supply and ballasts to eliminate harmonics. The old cables used to cook under full load but those ballasts are long gone

As I understand it, the neutral of a 3ph-4W circuit is considered conductor #4 and requires that an 80% multiplier be used for just one 4W circuit (plus gnd)? True or false?

Hi Mike. I have a question,concerned to the word -PHASE.

I understan the word how is applicable inside de motors,maybe is more easy cacht the idea in my brain,but I can't to diggestive in Service Box,when the cables enter the box, for example three cable enter in the box , each one is called Phase: PHASE A PHASE B PHASE C

Please,explain to me,because I have a little confuse about this, I will appreciate.