No, reason being that we are calculating a demand load on the breaker. At the same time there is no continuous load to be concerned with. The Code says nothing about 125% of the breaker for dwellings! CM
Good refresher, I work for a goldmine company in North easter nv. I like but hate it because the pay and benies are great but for all the actual sizing and brain work the mine contracts the work out so as an electrician we just become parts changers and never really use the math that much. Also MSHA has alot less electrical standards to follow than the NEC, the MSHA standard is probably less than 5 pages. Thank you for this amazing video!
I really appreciate your time and videos. 220 is soooo freaking difficult because the way it's laid out in the NEC. It's flippin' ridiculous. I'm still fuzzy about much that goes on in 220, but this helps a lot. Thank you.
I'm a Transportation Elec apprentice and trying to understand for the state exam. lots of practice questions with 120/240 supply voltage. Breaker calculation divides by 240. why not divide by 120?
I guess the main breaker is a 240 volt breaker? I was kinda surprised to see that too... figured that main breaker on the panel was 120, but i guess it is not.
Please don't take this as an insult or anything but... Shouldnt that main feeder breaker be at a minimum (125%) of the total load. Which would come to roughly 187. My inspectors would fail me if I had any breaker under 200 amps. At least that's what I was taught when I got my license. You're going to make someone have an electrical fire. You may want to remake this video brother.
This is also my understanding. I was hoping to get a definite answer from RU-vid about this but most videos are not multiplying the load by 1.25. So I’m still confused.
Hey craig thanks for posting this, it helped me to remember what I was taught in school👍🏼(it's been awhile lol) also I have a question, is the calculation the same for a commercial location?
Thank you so much for watching my video. As for your question, NO it is not the same. A commercial calculation is a little me involved. I plan on doing some non dwelling calculations in the future. Just not sure of a time frame. Thank you again for watching!! CM
I would if you could answer this question, I cant seem to find the answer anyware how do you measure the total amps for the entire breaker panel, for 240 devices [like an Dryer] you only measure 1 leg [10a x 240 = 2400 watts] for 120 devices you only measure one leg [hot to neuetral], and then [from my understanding ] the neutral carries the imbalance between the 2 legs, so in other words lets say you have 12 on one leg 15 on the other leg and lets say 3 on the neutral , the question is how do you read this for a true total amps . . i have searched high and low is what is the formula to take these 3 numbers and calcullate the total amps or watts ? if you know the answer id reaaly appreciate it FOR EXAMPLE ; L1 N L2 10A N 10A [240v DEVICE 2400Watt ] 2A N 5A [2 separate 120v devices L1 240 Watt L2 600 Watt ] TOTAL L1 N L2 [neutral carries the difference between the 2 legs from my understanding] 12A 3A 15A Total watts using what we actually know 3,240watts which is 13.5 amp at 240v but if you look at the amps above if you were to measure them it is in no way 13.5A and if you were to measure any of those it would not give you 3240 watts. So how do you actually do it?????? I have looked every where for this answer
Thank for the videos they are helping a lot. If you don’t have a compactor, disposal, or any other appliances like that, what do you use for the motor load portion of the calculation?
Great video. I'm planning on taking the test to become a licensed electrician in the near future hopefully. Watching this video was a big help. Thanks for sharing your knowledge with us viewers.
Won't some of those loads only be using a single pole breaker on a 120/240v panel so most loads would just be using 120v instead of 240 which would affect the total amperage?
This video is showing how to Calculate the service demand. Yes you have 120v circuits but you must base the load off of the service voltage which is 240v. You will need to know which of those 120v circuits used so that you can size the neutral but I did not go that far in these videos based on I was just showing how to size the service Breaker. CM
So basically determine the VA From each appliance and divide 240v then you know what system off the service pole will be needed is that correct I have a question determine the calculation and run for a new electrical grid to a 3 story dwelling 😬😬
Hi there Craig, I went through the videos to calculate for an ADU 360sqft. single family home and now I'm wondering if I came up with the correct number. My final calculation was 27.27Amps. what would be the breaker size for that?
Hello Craig👋! ... I have watched all service Calculations episodes as I have come to the Administrator test. I watched most of your videos when I was taking the EL01 journeyman electrician exam. I passed it with 82%. THANK YOU!! Now, hoping o pass my administrator exam on the first try. Your explanation o beak up the calculation is SO understanding!! I WISH I live in the same city you live in to be your student. I learned a lot from you. AND HANK YOU for speaking very clearly as English is my second language.!! Please, keep up with your GREAT videos! Would like o know more about PLC. I have been doing classic Control for 10+ years. I'm also in processing o reach 40% of learning PLC, HMI, SCADA, Factory I/O, TIA Portal, PC SIMU, CADe SIMU, VFD, and others related to PLC. Again, THANK YOU FOR ALL GREAT VIDEOS!🤗☺🌸🌷👍👌
love ur videos! when calculating total VA is the largest motor counted twice? my largest motor is in line10 as a fixed appliance (water heater 28kVA) and again in line14 as largest motor? (7000VA) @25%. thanks.
@@craigmichaud-electricalins4602 thanks for the clarification Mr Michaud. This video series has been an extremely helpful refresher and I like the way you structured adding up the calculation.👍
Hello there, Thank you very much for your video it’s very helpful. Just have one question; After calculating we get 147.25 amps. Which give us 150 amps breakers Let’s assume it’s THHN conductor and for that we got 1/0 from table 310.15.(B)(16) The question since it one phase 3 wire system 2 hot and one neutral are we going to divide the hot on 2 so can we use 2 conductors of size 6 AWG which each carries 75 amps or we use 2 conductors of 1/0 AWG which each carry 170 amps? Or we go to page 800 and choose size 1AWG for both conductors? Hope you got my point.
Great question!! The answer is NO. See the sizing of the wire is based on the load of the overcurrent device. So we are sizing the one leg as stated in the video. Also regardless of the wire type you will always want to use the 75 degree table to size any service over 100 amps. I hope this helps!! Thanks for the question and watching!! CM
I just came across this video so it might be to late for u to notice but have a question on your comment about using the column 75 degrees, I'm assuming that you and this person are talking about sizing the wire in table 310.16. So what about Table 310.12 Single-Phase Dwelling Services and Feeders. Cause this table would make it a #1 awg copper instead of a #1/0. ??
You prolly dont care but does someone know a tool to log back into an Instagram account..? I somehow forgot my password. I would love any tips you can give me.
@Ryder Ahmir thanks for your reply. I found the site through google and I'm trying it out now. I see it takes a while so I will reply here later with my results.
Craig, thank you for all the information you provide! It has helped me a lot in learning this trade. Quick question on this load calculation... When adding new electrical equipment to an existing home, will these same steps be taken to determine if the panel needs to be upgraded? A little confused since most of the time homes aren't drawing much for amperage, but by calculation on equipment they still need to be upgraded. Example being I'd like to add a Tesla charger to my own home.
Thanks for the video. I can't get a straight answer on this, hopefully you can help settle an argument... If you have a 200 amp residential main service panel and you get a reading of 105 amps on each of the main 120v feeders, are you drawing 210 amps, therefore the 200 amp panel is overloaded? Or is it only drawing 105 amps total?
