joshandkerr
New member
- Location
- Sioux Falls, SD
Missing Info? Mike Holt's "Standard Method Load Calculation" vs NFPA Annex D1(b)
Hi, hoping for some answers on this one.
I've pretty thoroughly gone through Mike Holt's "Electrical Exam Preparation" book based on the 2014 code for Standard Method Load Calculations on "One-Family Dwelling" units, actually even going to Arne Electric Tech's class for Master's exam preparation in Rapid City, SD.
Unit 9 of Mike Holt's "Electrical Exam Preparation" covers these single dwelling unit calculations. So, after test driving Unit 9, and taking the tests I felt I did pretty well. So, I decided to up the ante a bit and take my newly acquired skills to the code book. I decided to actually tackle the Informative Annex D "Example D1(b) in the back of the code. This example also builds on Example D1(a). And it's the standard method of one-family dwelling so I thought it would be easy.
I applied all that I had learned in Holt's book to their example and still missed the answer by 10 amps. :?
Here is how it breaks down for the calculations. Again, standard method is being used.
Dwelling unit square feet: 1500 x 3 = 4500VA
Small Appliance: 4500VA
9000VA total. First 3000VA at 100%. 6000VA at 35% = 2100VA
Total General Lighting and Recept: 5100VA
12kW Range: 8000VA
5.5kW Dryer: 5500VA
A/C unit: 115V, 12 AMP 1380VA
A/C unit: 230V, 6 AMP 1380VA
Disposer: 115V, 8 AMP 920VA
Dishwasher: 120V, 10 AMP 1200VA
Total: 23480VA / 240 = 97.83 amps.
A 100 Amp service should cover this IF you just follow the directions in Mike Holt's book on page 274 for a full "Standard Method Load Calculations Example."
However, when you follow the code book they come out with an 110 Amp service in Annex D1(b).
Why is this? What am I missing in Mike's very thorough calculation book and his didactic step-by-step method?
If anyone has some answers for me on this, please let me know. Thanks. Much appreciated as I will be taking my Master's test soon and I know this type of question will be on the test in Sioux Falls, SD!
Hi, hoping for some answers on this one.
I've pretty thoroughly gone through Mike Holt's "Electrical Exam Preparation" book based on the 2014 code for Standard Method Load Calculations on "One-Family Dwelling" units, actually even going to Arne Electric Tech's class for Master's exam preparation in Rapid City, SD.
Unit 9 of Mike Holt's "Electrical Exam Preparation" covers these single dwelling unit calculations. So, after test driving Unit 9, and taking the tests I felt I did pretty well. So, I decided to up the ante a bit and take my newly acquired skills to the code book. I decided to actually tackle the Informative Annex D "Example D1(b) in the back of the code. This example also builds on Example D1(a). And it's the standard method of one-family dwelling so I thought it would be easy.
I applied all that I had learned in Holt's book to their example and still missed the answer by 10 amps. :?
Here is how it breaks down for the calculations. Again, standard method is being used.
Dwelling unit square feet: 1500 x 3 = 4500VA
Small Appliance: 4500VA
9000VA total. First 3000VA at 100%. 6000VA at 35% = 2100VA
Total General Lighting and Recept: 5100VA
12kW Range: 8000VA
5.5kW Dryer: 5500VA
A/C unit: 115V, 12 AMP 1380VA
A/C unit: 230V, 6 AMP 1380VA
Disposer: 115V, 8 AMP 920VA
Dishwasher: 120V, 10 AMP 1200VA
Total: 23480VA / 240 = 97.83 amps.
A 100 Amp service should cover this IF you just follow the directions in Mike Holt's book on page 274 for a full "Standard Method Load Calculations Example."
However, when you follow the code book they come out with an 110 Amp service in Annex D1(b).
Why is this? What am I missing in Mike's very thorough calculation book and his didactic step-by-step method?
If anyone has some answers for me on this, please let me know. Thanks. Much appreciated as I will be taking my Master's test soon and I know this type of question will be on the test in Sioux Falls, SD!
