# 20Kw heat strips #4 circuit



## erics37 (May 7, 2009)

I just do what the nameplate sticker tells me to do.


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## aftershockews (Dec 22, 2012)

erics37 said:


> I just do what the nameplate sticker tells me to do.


Most 20Kw I have done either had 2 60 amp 2 pole breakers or 4 60 amp fuses. I tried explaining to the boss that we need to run #2.


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## drspec (Sep 29, 2012)

I haven't wired up a 20 kw in years. If I remember right, a couple of the ones I wired had a 60 amp 2 pole and 2 - 30 amp 2 pole breakers. 
We would run #2 SEU copper. But that was probably 12 years ago.


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## Dennis Alwon (May 9, 2009)

I don't recall every being allowed to wire a heater without using 125% but I am not as old as your boss. The funny thing is that he got it passed all those years


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## ralpha494 (Oct 29, 2008)

The way I see it: 20,000W/ 240V = 83.3A 
210.19 (A)(1) 125%. 83.3 x 1.25 = 104.2 
#3 THWN-2 or #2 THW or #1 TW
It could be #1 THWN-2 if the terminations are 60 degrees.


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## raider1 (Jan 22, 2007)

ralpha494 said:


> The way I see it: 20,000W/ 240V = 83.3A
> 210.19 (A)(1) 125%. 83.3 x 1.25 = 104.2
> #3 THWN-2 or #2 THW or #1 TW
> It could be #1 THWN-2 if the terminations are 60 degrees.


#3 THWN-2 would not work because it has an ampacity of 100 amps at 75 degrees C. You would not be able to use the 90 degree column because there is no equipment that is rated for 90 degrees C.

The 90 degree column is used for ampacity adjustments.

Chris


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## hardworkingstiff (Jan 22, 2007)

aftershockews said:


> Most 20Kw I have done either had 2 60 amp 2 pole breakers or 4 60 amp fuses. I tried explaining to the boss that we need to run #2.


What size does the boss want you to install?


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## aftershockews (Dec 22, 2012)

hardworkingstiff said:


> What size does the boss want you to install?


Boss is determined to run #4. I wont be doing this job as I am busy. He is sending another crew to do this.


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