I heard a comment that I still use when teaching this material. FLC = Full Load CODE, use the tables to size conductors, OCPD, devices. FLA = Full Load ACTUAL use for sizing the Overloads. Great little cheat, for remembering it.
Sure, the NEC sits there accessible in our rooms, work vehicles & classrooms etc. It's instructors like this gentleman, however, who inspire us to read and apply it to our work. Good teachers are a gift to the world, thank you for sharing, sir.
Great material. I'm mostly unfamiliar with NEC and motors and have my exam soon. This helped simplify the application and how to find the information in 430. Great examples and little tips to help navigate the material quicker
Thanks! You're an excellent instructor. You clearly explain the concept, address the nuance, anticipate and answer questions, and explain the "why" and applications.. Excellent. I wish many of my flight instructors were as good.
That is exactly it, the why to me is really important. I know a lot of guys that just say hey that's code so just do it, but having that why really helps me understand the code a lot more.
I really enjoy your videos. The topic is explained in a very logical and easy to understand way. Much better than procedural instruction given at school: you do this, then take this and based on that you do that because the table allows you this if that but not this because of that. Thank you. You helped another electrician to enjoy his job.
Ryan, always a pleasure watching you and I love the refreshers. Being a little bold and hopefully not requesting too much, I'd love a refresh on multi-motor crane calculations and arc welder calculation for conductor, etc. Again, thank you for everything you do for the electrical community!!!
I love the videos man. Nice to have a guy like you that helps clarify some things in the code. Im always bugging the masters and other journeyman I know about code and you are honestly a better resource them some of them.
I need to replace the service on my house, I am a union electrician, I normally do not do Residential work.I would like to see a video from you about what I need to know about arc fault breakers. I graduated from my locals apprenticeship program in 1996, way before arc fault circuits.
I'm a little confused about when to use the 430.6 (1) Exception No 3. 42 minutes into this video, there's a motor nameplate with both HP and full load current. Why are the NEC Part XIV tables used instead of the nameplate values?
Kind regards, I have a question. I understand the methodology applied for overcurrent protection, but I don't fully understand its reasoning. Why are protections calculated with these maximum settings? In my opinion, it becomes confusing for the following reasons: If I have a 90 kW motor at 440 VAC, its nominal current is approximately 145 A. The starting current is around 1140 to 1200 A (in a direct start). Now, to determine the overcurrent protection according to Article 430.52, assuming an instantaneous protection device with a maximum setting of 800% FLC, it would be 1160 A, which commercially would mean a 1200 A device (magnetic function only). Commonly, these devices are designed to trip magnetically at (10 x In, single setting), which is approximately 12 kA. This is where I am confused: why would you use a nominal 1200 A switch (magnetic protection only) for a 145 A load as overcurrent protection? I would appreciate it if you could clarify my doubt.
@jefersonsanchezjerez7000 You have to remember that the overcurrent device you discuss is not protecting against overcurrent...it is protecting against ground faults and short circuits. A fault shall result in thousands of amperes, opening the device in a timely (safe) manner. The "normal" current of the motor is only used for protection against overloads. For a non-motor application, protecting against all three types of overcurrent can easily be done with one breaker or fuse. For a motor it is very hard to protect against overloads while allowing the motor to start up with a single device.
@@RyanJacksonElectrical First of all, thank you very much for taking the time to respond. I agree with what you said, the device is protecting against short circuits or ground faults, where the overcurrents are in the kA range. The settings established in the standard allow for differentiation between current during startup and faults due to short circuits or ground faults. However, personally, I still believe that these maximum settings are quite high. One last question: you mentioned that it is complex to provide protection against overload and short circuit with a single device, but for example, motor circuit breakers (such as the Schneider GV3P80) are designed for magnetic tripping between 14 to 16 times the motor's rated current (FLC). This would provide good discrimination during startup, which is typically between 6 to 8 times the motor's nominal current (FLC) in a direct start. Of course, there will be special cases where this would not be sufficient, but in most cases, it should be applicable, right?
@@jefersonsanchezjerez7000 In most cases, the values in the NEC table work fine. But the NEC also recognizes that they will not always work, so the NEC gives the allowances in 430.52(C)(1)(b). Note that 430.52(B) always applies, so if the numbers in 430.52(C)(1)(b) don't work you would have to use a different protection method.
I disagree with the too high of a value motor amps when connecting 2, 4 or 6 pole plain jane Nema frame motors that in my 50 years as a commercial electrician covered over 99% of installtions. Of the thousands of motors that I have replaced, moved, installed or PM'ed never came across a single motor that was within 10% of the NEC ampere. Just went 125% of the motor FLA & if a long run would calculate voltage drop and would increase wire size if needed. We had AHU'S that had two 60 to 125 HP motors where both supply motors ran 24/7 but seldom over 50% of full speed and on VFD'S. I could run over 1200 amps of AHU motors from a 800 amp distribution panel for 50 years snd never trip out the 800 amp breaker because of constant reduced speeds feed from VFD'S. Only time a supply motor ran close to full speed was when other motor was down for PM or rare replacement.
Please note that I somehow put 115V instead of 230V. At 230V, the motor is is 8A. At 115V, the motor would be 16A. Sorry for that.
I heard a comment that I still use when teaching this material. FLC = Full Load CODE, use the tables to size conductors, OCPD, devices. FLA = Full Load ACTUAL use for sizing the Overloads. Great little cheat, for remembering it.
Sure, the NEC sits there accessible in our rooms, work vehicles & classrooms etc. It's instructors like this gentleman, however, who inspire us to read and apply it to our work.
Good teachers are a gift to the world, thank you for sharing, sir.
Agree. He's an outstanding instructor!
Great material. I'm mostly unfamiliar with NEC and motors and have my exam soon. This helped simplify the application and how to find the information in 430. Great examples and little tips to help navigate the material quicker
A very gifted instructor.
Thanks! You're an excellent instructor. You clearly explain the concept, address the nuance, anticipate and answer questions, and explain the "why" and applications.. Excellent. I wish many of my flight instructors were as good.
Thanks for the donation! And thanks for the kind words, that's very nice of you to say.
@@RyanJacksonElectrical You're quite welcome, Ryan!
That is exactly it, the why to me is really important. I know a lot of guys that just say hey that's code so just do it, but having that why really helps me understand the code a lot more.
@@jsb7546 Absolutely!
I have learned so much from you Ryan. You make me a better electrician. Thank you.
Thanks for all you do Ryan. One of the best instructors out there. Great video
Definitely. He's excellent!
I really enjoy your videos. The topic is explained in a very logical and easy to understand way. Much better than procedural instruction given at school: you do this, then take this and based on that you do that because the table allows you this if that but not this because of that. Thank you. You helped another electrician to enjoy his job.
Ryan, always a pleasure watching you and I love the refreshers.
Being a little bold and hopefully not requesting too much, I'd love a refresh on multi-motor crane calculations and arc welder calculation for conductor, etc.
Again, thank you for everything you do for the electrical community!!!
I watched the entire video it helped me better to understand article 430 about motors rules . Thank you..
Thank you, Ryan. Love your explanation and concept as it is easy to understand.
I love the videos man. Nice to have a guy like you that helps clarify some things in the code. Im always bugging the masters and other journeyman I know about code and you are honestly a better resource them some of them.
Awesome video, very informative! Thank you, Ryan.
Awesome information. Thank you.
One word, Just Excellent.
Excellent video!! Thank you.
I need to replace the service on my house, I am a union electrician, I normally do not do Residential work.I would like to see a video from you about what I need to know about arc fault breakers. I graduated from my locals apprenticeship program in 1996, way before arc fault circuits.
Thank you Ryan!
would you do a video on 225.30
@@Jeremiah9909 Great idea! Part II of Article 225 is so misunderstood
Mr Jackson you are Mike Holt's successor.
is voltage drop a factor if the motor is 150ft, 30Hp 3Ph?
I'm glad I only have to size the circuit for my 6.5hp shop vac based on the FLC (13A). Otherwise it looks like I'd need an 80A 120V circuit for it!
I'm a little confused about when to use the 430.6 (1) Exception No 3. 42 minutes into this video, there's a motor nameplate with both HP and full load current. Why are the NEC Part XIV tables used instead of the nameplate values?
Kind regards, I have a question. I understand the methodology applied for overcurrent protection, but I don't fully understand its reasoning. Why are protections calculated with these maximum settings? In my opinion, it becomes confusing for the following reasons: If I have a 90 kW motor at 440 VAC, its nominal current is approximately 145 A. The starting current is around 1140 to 1200 A (in a direct start). Now, to determine the overcurrent protection according to Article 430.52, assuming an instantaneous protection device with a maximum setting of 800% FLC, it would be 1160 A, which commercially would mean a 1200 A device (magnetic function only). Commonly, these devices are designed to trip magnetically at (10 x In, single setting), which is approximately 12 kA. This is where I am confused: why would you use a nominal 1200 A switch (magnetic protection only) for a 145 A load as overcurrent protection? I would appreciate it if you could clarify my doubt.
@jefersonsanchezjerez7000 You have to remember that the overcurrent device you discuss is not protecting against overcurrent...it is protecting against ground faults and short circuits. A fault shall result in thousands of amperes, opening the device in a timely (safe) manner. The "normal" current of the motor is only used for protection against overloads. For a non-motor application, protecting against all three types of overcurrent can easily be done with one breaker or fuse. For a motor it is very hard to protect against overloads while allowing the motor to start up with a single device.
@@RyanJacksonElectrical First of all, thank you very much for taking the time to respond. I agree with what you said, the device is protecting against short circuits or ground faults, where the overcurrents are in the kA range. The settings established in the standard allow for differentiation between current during startup and faults due to short circuits or ground faults. However, personally, I still believe that these maximum settings are quite high. One last question: you mentioned that it is complex to provide protection against overload and short circuit with a single device, but for example, motor circuit breakers (such as the Schneider GV3P80) are designed for magnetic tripping between 14 to 16 times the motor's rated current (FLC). This would provide good discrimination during startup, which is typically between 6 to 8 times the motor's nominal current (FLC) in a direct start. Of course, there will be special cases where this would not be sufficient, but in most cases, it should be applicable, right?
@@jefersonsanchezjerez7000 In most cases, the values in the NEC table work fine. But the NEC also recognizes that they will not always work, so the NEC gives the allowances in 430.52(C)(1)(b). Note that 430.52(B) always applies, so if the numbers in 430.52(C)(1)(b) don't work you would have to use a different protection method.
Nice build up to 430.6 - overcoming inertia
Thank you!
See you in Bay City once again!!
Looking forward to it!
At minute 38, I believe 1hp 115 v motor according to .248 is 16 amps. is this correct. you have 8.0 amps. This is true at 1hp @ 260 volts I believe.
Yep. See the pinned comment. It was caught too late by someone like yourself that had keener eyes than I do. Well caught!
🔥
I disagree with the too high of a value motor amps when connecting 2, 4 or 6 pole plain jane Nema frame motors that in my 50 years as a commercial electrician covered over 99% of installtions. Of the thousands of motors that I have replaced, moved, installed or PM'ed never came across a single motor that was within 10% of the NEC ampere. Just went 125% of the motor FLA & if a long run would calculate voltage drop and would increase wire size if needed. We had AHU'S that had two 60 to 125 HP motors where both supply motors ran 24/7 but seldom over 50% of full speed and on VFD'S. I could run over 1200 amps of AHU motors from a 800 amp distribution panel for 50 years snd never trip out the 800 amp breaker because of constant reduced speeds feed from VFD'S. Only time a supply motor ran close to full speed was when other motor was down for PM or rare replacement.
Hi all! Why most of the electrical designer I know is using 175% NOT 250% to size breaker for a single motor?
47:26😂
This is probably the stupidest question, but would generators be under the same constraints?
if you pulse DC power, you will get more out than in