Single Family Dwelling Load Calculations. Solving for OCPD. (NEC 2020)
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- Опубликовано: 15 мар 2022
- I cannot provide a copy of the worksheet. But it is more of a burden than a help. Here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
Res. Load Calc: • Residential Load Calcu...
Optional Method: • Optional Method Load C...
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(A few vids I posted on my other channel before making this channel) :
Sizing Conduit
• Sizing Conduit (NEC 2020)
FLC Motors
• Figuring Out Full Load...
Sizing Pull Boxes
• Sizing pull boxes (NEC...
Impedance
• How to solve for imped...
ERRATUM: 33:58 Sizing wire from OCPD, there is no need to multiply by 1.25. Furthermore I should have not used Table 310.16 because I need to math in the 83% rule for Residential Load Calc. This is already calculated for you in Table 310.12.
So in this circumatance with 179.94 which gave us the 200 Amp OCPD (T240.6 (A)) we would then go into table 310.12 and find 200 amps and then match it with the correct wire size. In this senario 200 amps (T310.12) will give us: 2/0 cu. and 4/0 al. As you can see from the header of Table 310.12, it is for Services and also Feeders. The wires from the load side of the service attatching to the main breaker (OCPD) would be considered feeders.
I will redo this portion of the video in a new video where I can explain it better.
I cannot provide a copy of the worksheet. But it is more of a burden than a help, here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
ruclips.net/video/er07gUB1l7g/видео.html&t
Optional Method Video: ruclips.net/video/qjgStSt4xJo/видео.html&t
Great Work! Do you have a worksheet / video for the Optional Method?
Thanks! Yes it is one of my most recent videos, here is the link:ruclips.net/video/qjgStSt4xJo/видео.html&t
Also, I have a newer video on the standard method where I show the process without a worksheet, which is more realistic to the actual test so I highly recommend that video too. It is called Residential Load Calculations, here is the link:ruclips.net/video/er07gUB1l7g/видео.html
Is the first time I've seen the total load been multiply by continuos load I am saying this because I have wacht Mike Holt, Ryan Jackson and The electrical code coach videos and they always apply the 83% rule to the service wires that is why we put 200 OCPD on a 4/0 aluminium Could you please tell me where in the code I can find that we have to multiply the total load by 1.25 and I will apreciate it...
so when do we use the 83% rule?
i thought we use it on service feeders
This was a mistake that I had not realized at the time, look for my pinned comment at the top of the comments for an explanation.
@@erikdaelectrician6102 This was a mistake that I had not realized at the time, look for my pinned comment at the top of the comments for an explanation.
I really like your video. I have a question, if we know the total VA of general light and receptacle, can we know exactly how many lights and outlets are there in that dwelling unit
The exact amount would not be known but there are minimums. Such as a minimum number of branch circuits on General Lighting using #14 AWG or #12 AWG. You would figure this out by getting your sqft multiplied by 3va. Then From this number dividing it by 120v then divide that by the amps you are working with, 15a or 20a. This will tell you how many branch circuits you have with this portion plus an additional FOUR 20-amp Branch Circuits for: 2 SABC, 1 Laundry Circuit, and 1 Bathroom circuit.
For example: if you had a 2,500 sqft dwelling then you would first do
2,500 x 3 = 7,500 from here you divide by 120.
7,500 / 120 = 62.5 from here you divide by the amps you are working with, first I will do 15A for #14 AWG.
62.5 / 15 = 4.166
You always round up to the NEXT whole number. So even though you normally would not round up 4.166 in this case you always round up to the next whole number.
4.166 becomes 5.
This means you need 5 Branch Circuits for this 2,500 sqft dwelling plus an additional FOUR 20-amp Branch Circuits as explained above.
This is a complicated area because they might ask how many general purpose branch circuits you would need... this means instead of the additional 4 you would only count the 5 for the lighting portion.
If you had 20A for #12 AWG then you would divide accordingly:
62.5 / 20 = 3.125
again round up to the NEXT whole number
Now you can have 4 General Purpose Branch Circuits for this 2,500 sqft dwelling and if you are doing the entire General Lighting Load you should know the additional FOUR 20-amp branch circuits explained above.
Thanks. I would appreciate a copy of the load calculation sheet.
Unfortunately I realized it has a copyright on it and I cannot technically be distributing it. In all it is really simple and you could easily draw it, and doing so you would probably memorize it...
Hello I would like a copy of your worksheet ? Thanks
I cannot provide a copy of the worksheet. But it is more of a burden than a help, here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
Residential Load Calc:ruclips.net/video/er07gUB1l7g/видео.html&t
Optional Method Video: ruclips.net/video/qjgStSt4xJo/видео.html&t
Hey! I would like a copy of your worksheet please. Great video btw, thank you!
I cannot provide a copy of the worksheet. But it is more of a burden than a help, here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
Residential Load Calc:ruclips.net/video/er07gUB1l7g/видео.html&t
Optional Method Video: ruclips.net/video/qjgStSt4xJo/видео.html&t
I would like a copy of that sheet
I cannot provide a copy of the worksheet. But it is more of a burden than a help, here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
Residential Load Calc:ruclips.net/video/er07gUB1l7g/видео.html&t
Optional Method Video: ruclips.net/video/qjgStSt4xJo/видео.html&t
For dwellings you gotta use Table 310.12 for service feeder conductors. We are over sizing the heck out of wire.
This was a mistake that I had not realized at the time, you are correct and thank you.
Why 200 amps at 1.25%? I’m confuse
This was a mistake that I had not realized at the time, look for my pinned comment at the top of the comments for an explanation.
Hey how do I get that work sheet
I cannot provide a copy of the worksheet. But it is more of a burden than a help, here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
Residential Load Calc:ruclips.net/video/er07gUB1l7g/видео.html&t
Optional Method Video: ruclips.net/video/qjgStSt4xJo/видео.html&t
Pls don't be confused VA != W (there is a Pf in W)
VA and W are used interchangeably in load Calc. I forgot about this since I hadn't done it in a while. You are correct in real life, but here we use them the same.
How can I contact you??
javujo@gmail.com
I want that paper I want to take the exam so what ever tips you. Have you can send it to me
Please
Unfortunately I realized it has a copyright on it and I cannot technically be distributing it. In all it is really simple and you could easily draw it, and doing so you would probably memorize it...
Get this : www.amazon.com/Master-Electrician-Questions-Answers-Henry/dp/1733462112/ref=pd_bxgy_img_sccl_1/139-2602853-3801357?pd_rd_w=i2jiT&content-id=amzn1.sym.26a5c67f-1a30-486b-bb90-b523ad38d5a0&pf_rd_p=26a5c67f-1a30-486b-bb90-b523ad38d5a0&pf_rd_r=7515P2T7YKQZ2XRTSVTW&pd_rd_wg=EcBuU&pd_rd_r=9e786a00-e08a-431e-b86a-123de7dfa7bb&pd_rd_i=1733462112&psc=1
and this!
www.amazon.com/American-Electricians-Handbook-Frederic-Hartwell/dp/1260457915/ref=sr_1_1?crid=2Y6O5HE6FBY83&keywords=electricians+handbook&qid=1693394030&s=books&sprefix=electricians+handbook%2Cstripbooks%2C148&sr=1-1&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0
I caught at least two mistakes with your math before the video ended.
Where?
This is crap
It is hard to work with someone with remarks like that... I have a newer video if you are trying to learn. ruclips.net/video/er07gUB1l7g/видео.html&t
@@jarodvelectric7431 you’ll never get to a 200 amp panel at 1200’ home.
@@MarioLopez-iv2nw The point is not the answer it is how you got there... You must be very difficult in real life.
@@MarioLopez-iv2nw Go make your own video then buddy.
I would like a copy of that sheet
I cannot provide a copy of the worksheet. But it is more of a burden than a help, here is my newer video on Residential Load Calc that explains a method that relies on the book which is more accurate to a testing scenario. (Vid Below)
Residential Load Calc:ruclips.net/video/er07gUB1l7g/видео.html&t
Optional Method Video: ruclips.net/video/qjgStSt4xJo/видео.html&t