Hello, can I ask a random question? I purchased a lot of your streaming courses and I’m slowly working my way through them. Right now I’m taking your advice to rewatch the Fundamentals course before moving on to the NEC Volume 1 course (which is a good idea, there’s so much to take in). Anyway, I’m not sure if I missed this, or if it’s obvious and I’m about to ask a stupid question lol…but let’s say that we have a 480V primary and 120V secondary step down transformer. Ok so I think that I fully understand that grabbing either individual winding will shock me relative to the proportion of distance that I grab across that winding. For instance, as a totally made up hypothetical example let’s say that the primary winding is 48 inches long (and that the starting point is ‘Point A’, and the ending point that is 48 inches away is ‘Point B’)…and let’s say that the secondary winding is 12 inches long (and likewise it’s starting point is ‘Point C’, and it’s ending point that is 12 inches away from that is ‘Point D’). So, point B is where the neutral and the ground rod of the primary winding are bonded…and point D is the equivalent point for the secondary winding. Ok so I understand that if I start grabbing anywhere along the points between A and B, or anywhere between the points between C and D, that I will get shocked with a difference of potential that’s relative to the length of the winding. For instance if I grab point A with my left hand, and then grab the primary winding 12 inches away from point A with my right hand…I will get shocked with 120 volts of potential difference (because I grabbed across 25% of the length of a 480V winding). And if I grab point C of the secondary winding with my left hand, then grab directly in the middle of that winding (6 inches away) I will get shocked with 60V. Etc. And…if I grab point B or point D with both hands, I won’t get shocked at all because it’s the same exact potential. So I think that I’m totally clear on that. But what I’m not sure about is the potential differences ACROSS the primary and secondary windings. If I grab points B and D for instance, is that 0 volts? If I grab exactly halfway between points A and B (24 inches from each end) on the primary, and with my other hand I also grab the center of the secondary winding (6 inches from points C and D) is that 0 volts? Etc? I’m not totally clear about the potential differences that exist ACROSS a primary and secondary winding of the same transformer. I think that everything that I said in the hypothetical situation is true, but I’m not positive, and hopefully you could tell me if I’m understanding it correctly. Thanks!
Good day. Would residental lift stations also require GFCI protection? Cord connected? Hard wired with a disconnect? My interpretation would say yes regardless. Thank you.
![Auxiliary Grounding Electrodes [250.54], NEC 2023, (10min:54sec)](http://i.ytimg.com/vi/4a8Kh5aLCB0/mqdefault.jpg)
![Auxiliary Grounding Electrodes [250.54], NEC 2023, (10min:54sec)](/img/tr.png)
![GFCI Receptacle Protection, Dwelling Units [210.8(A), 2020 NEC Changes]](/img/n.gif)
Thank you for sharing your knowledge
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Hello, can I ask a random question? I purchased a lot of your streaming courses and I’m slowly working my way through them. Right now I’m taking your advice to rewatch the Fundamentals course before moving on to the NEC Volume 1 course (which is a good idea, there’s so much to take in).
Anyway, I’m not sure if I missed this, or if it’s obvious and I’m about to ask a stupid question lol…but let’s say that we have a 480V primary and 120V secondary step down transformer. Ok so I think that I fully understand that grabbing either individual winding will shock me relative to the proportion of distance that I grab across that winding. For instance, as a totally made up hypothetical example let’s say that the primary winding is 48 inches long (and that the starting point is ‘Point A’, and the ending point that is 48 inches away is ‘Point B’)…and let’s say that the secondary winding is 12 inches long (and likewise it’s starting point is ‘Point C’, and it’s ending point that is 12 inches away from that is ‘Point D’). So, point B is where the neutral and the ground rod of the primary winding are bonded…and point D is the equivalent point for the secondary winding.
Ok so I understand that if I start grabbing anywhere along the points between A and B, or anywhere between the points between C and D, that I will get shocked with a difference of potential that’s relative to the length of the winding. For instance if I grab point A with my left hand, and then grab the primary winding 12 inches away from point A with my right hand…I will get shocked with 120 volts of potential difference (because I grabbed across 25% of the length of a 480V winding). And if I grab point C of the secondary winding with my left hand, then grab directly in the middle of that winding (6 inches away) I will get shocked with 60V. Etc. And…if I grab point B or point D with both hands, I won’t get shocked at all because it’s the same exact potential.
So I think that I’m totally clear on that. But what I’m not sure about is the potential differences ACROSS the primary and secondary windings. If I grab points B and D for instance, is that 0 volts? If I grab exactly halfway between points A and B (24 inches from each end) on the primary, and with my other hand I also grab the center of the secondary winding (6 inches from points C and D) is that 0 volts? Etc? I’m not totally clear about the potential differences that exist ACROSS a primary and secondary winding of the same transformer. I think that everything that I said in the hypothetical situation is true, but I’m not positive, and hopefully you could tell me if I’m understanding it correctly. Thanks!
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Hello Mike please do the video on Generator set and it's temporary earthing cable size
None required for systems under 1000V.
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Ho guardato questo video al lavoro e ora anche i miei colleghi stanno ridendo. Un ottimo modo per risollevare l'umore in ufficio🍭
Good day. Would residental lift stations also require GFCI protection? Cord connected? Hard wired with a disconnect? My interpretation would say yes regardless. Thank you.
Yes
Hey Mike, what about pool heaters?
Nope, per the exception to 210.8(F).
Also, the HVAC equipment is hardwired (no plug/outlet)
Not for HVAC equipment, exception was added later.
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My interpretation, would include oudoor pool pumps less than 50A, water pumps, etc.
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Only if the pool pumps are 110V, most are 220V ?
210.8(F) applies to 120V, 240V, and 120?240V circuits. The 150V to ground means any circuit where the voltage to ground does not exceed 150V.
@@MikeHoltNEC it’s been a long time, retired 13 years, I like your channel, like to keep somewhat abreast of the industry. Thanks.
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