How To Derate Electrical Conductors

[@cameronforbes2649]

This was what I needed short and simple right to the point.

[@MountaineerOutdoors]

Awesome glad to hear that this helped you

[@icevariable9600]

For 2023 NEC, the percentage adjustment factors are in Table 310.15(C)(1), not Table310.15(B)(2). This video was fantastic!!! Thank you SO much! I was unaware of the asterisks and to use the values from Section 240.4(D), even though it was right in front of my stupid face. You really helped.

[@MountaineerOutdoors]

Glad to hear that this helped you. Thanks for watching and commenting ☺

[@icevariable9600]

@@pld8993 Maybe you misunderstood. We literally do use the values from 240.4(D) for the size of the OCPD where it literally says: “after any correction factors for ambient temperature and number of conductors have been applied”. I know you’re trying to be snarky, and I know electricians hate to be proven wrong; but in this instance, the code (again) literally says to not exceed the values of 240.4(D) after applying derating of temperature and bundling. But by all means, go ahead and double down and ignore what I said. It’s expected.

[@icevariable9600]

@@pld8993 I stand corrected. I responded without rewatching the video. I hadn’t seen this video for a while, and you’re right, he’s derating from the 60°C column. He should be derating the 10 AWG from the 90°C column in Table 310.16. So, you were right.

[@MrTommysupra13]

You are supposed to use the 90 degree table and it’s worth 40.

[@kodykarlik5221]

No

[@jeremyragsdale8530]

In the 2021 NEC. Table 310.16 for 10awg wire that is THHN, it is showing a rating of 40amp. So wouldn’t you go 40 x .80? For type TW, UF you would use the 30amps for 10awg

[@MountaineerOutdoors]

You need to pay attention to the asterisk. It steers you to another code number for the clarification. If you need further information about this please don't hesitate to ask me. But do check out the asterisk

[@Ed-uu9eo]

@@MountaineerOutdoors pretty sure when you’re “derating or adjusting” you use the actual rating of the insulation. Which would be 40 amp on 90 degree column.

[@Journeyman1642]

It’s article 310.15 (b) (16)

[@omarmarquez2976]

Hey thank you for the information i have a question does this applies lets say if i run 1 1/2 pipe i cant run more than 6 wires?

[@MountaineerOutdoors]

No every wire size and conduit size falls into different categories.

[@omarmarquez2976]

@@MountaineerOutdoors thank you ! Where can i learn more about that ? About how many conductors on a pipe

[@MountaineerOutdoors]

kzbin.info/www/bejne/qXfZhXh6l82bbrc

[@oscar27ization]

THHN 90 degree column number 10!is rated for 35amps?

[@luis_ayala_134]

Great video as usual 👍

[@jorge197]

How many 12-2 wire can i run in a 1 inch hole? Thanks

[@brianhogan433]

Can you help me interpret 110.14C. I read at it as the adjustment can be used at the max value of the insulation and as long the corrected valve is not exceeding my terminal rating. My example is 6 current carrying #10 THHN. My air conditioning equipment max amp rating was 29.1A. My terminal ratings was 75°C My stance was 80% of 40A (#10 @ 90C) = 32A wire My 75°C terminations not to exceed 35A I want to say my adjusted wire ampacity can handle 29.1 as well as my terminations can handle 29.1. Great video. Wondering your thoughts on a situation like this.

[@mac_361]

Good stuff

[@hutotgab]

Hi Sir, I’m running in to a situation where the plan has Voltage drop calculations already what that means is it asks #4 for a 20A fridge. The usage is 12.5 A The run is 300 feet . To safe labor and conduit I’m planning to run 1”1/2 conduit I’ll have 16 current carry conducor. How do I figure out if the 50% derate? Thank you for the answer 🙏

[@1k90ol6]

Very helpful ty

[@MountaineerOutdoors]

My pleasure thanks for watching and commenting ☺

[@gregriley649]

Awesome video thank you for sharing .👍

[@MountaineerOutdoors]

Always my pleasure ☺

[@rezzle2457]

Thank you so much, very helpful

[@MountaineerOutdoors]

My pleasure thanks for watching and commenting ☺

[@prestinb]

Is this formula for total number of conductors (including neutrals/grounds) inside conduit or just total number of hots in a conduit?

[@MountaineerOutdoors]

It's all current carrying conductors. Nuetral and hots.

[@Shon-z7w]

Do I have to derate if the conduit is only 5 feet?

[@MountaineerOutdoors]

Yep if it's 2 foot you can use the 60% column not what you asked but I was just sharing that with you.

[@Yummyfudge]

One thing can really add up, it to define what a "current carrying conductor" is. If all your working in is 3 phase, no neutrals, this works, but if you have single (split) phase 240, your neutral may not always be counted as a current carrying conductor. Otherwise, great and to the point.

[@NicholasTheGreat]

I get the math, but in your first example, what does that 24 amps look like in the field? My load (say a heater) can’t exceed 24 amps for that specific circuit? Or my breaker must be 24a or larger

[@mr.g937]

How do you actually enforce this derating of conductors? People are still going to throw a 30 amp breaker on that 10 guage conduit run no?

[@MountaineerOutdoors]

Yep your exactly correct. However once someone needs the correct voltage and items start failing or you check voltage and see that your true voltage isn't what it's supposed to be that's when you will have to think about fixing the problems. As far enforcing it goes, a true electrician or company will definitely know what to do. It's kinda like the speed limit.. Its posted but not alot of people abide by it.

[@Calebjones87]

I understand the math. I don’t understand what is the math for as in Are you pulling that many wire in conduit for one breaker? If one 10 gauge wire is 30 amp why are you worry about 10 wire equal to 30 amp. That what I was confuse about this video

[@MountaineerOutdoors]

Sometimes you pull out of a commercial or industrial panel and leave with more than one circuit. It's to keep you from over filling.

[@theoisaac9948]

💯👍