Difference Between VOLTAGES - Why We Need Them All
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- เผยแพร่เมื่อ 3 มิ.ย. 2024
- What is the difference between all of these different voltages? Why are they used, what's the purpose behind them, and where do the numbers come from?
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Low Voltage systems (50 volts and below) are typically used for communication and signaling. These are far less dangerous voltages to come into contact with which is why they're not regulated by the National Electrical Code. These are 5, 10, 12, 16, 20, 24 volts for example. A lot of doorbell transformers, LED drivers, power supplies, and dimming controllers use these voltages in either an AC or DC pulse to control the switching on and off of other equipment.
Next is the Medium Voltages that we use as electricians, and this is anything from 100 volts to 250 volts. This is typically what you'll see in homes and small businesses. 120 volts and 240 volts for a single-phase, and 120, 208, and 240 for three-phase. Depending on how a transformer is wound at the service, you'll have 208/120 or 240/120, and in the case of a 3phase 4wire Delta application, you'll have 208/240/120 all in the same service.
Last is the High Voltages that are found in a lot of larger office buildings or places with really powerful equipment like industrial factories and plants. This is the 277-600 volt range, and most commonly you're dealing with voltages at 277/480. Just like 120/208 means that between hot and neutral you have 120 volts, and between two hots you have 240 - in a 277/480 service the voltage between hot and neutral is 277 and the voltage between two phase (hot) conductors is 480 volts. It's just a lot stronger push.
How these numbers come to be is simply how power is generated and transformed, which could have its own video entirely, but you can see in a 120/240 environment that 120 volts are simply half of 240. This means that the incoming 240 volts are being tapped in the center so there are two 120 volt circuits now able to be used within that 240-volt system. When dealing with 3-phase systems, however, we use the square root of 3 or (1.732) in all of our calculations to account for the phase angles of all of the windings and how they're being generated. So if you're wondering how we get numbers like 208, 277 you use 1.732 (because they're three-phase voltages). For example 480 / 1.732 = 277 volts, and 120 x 1.732 = 208 volts.
#voltage #potential #electrical
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I can't say it enough Dustin, but you are a great teacher. My former instructor could not explained this as clear as you did. Great job.
I wante work for you
Aba Kara I want to not work for you
I had an aunt faye. All her stuff was fays stuff.
@@abakara4859 no go find a job somewhere else
0
Thanks for taking the time to reply. When I applied for an apprenticeship (in 1967) you needed a sponsor, or relative in the business. Unfortunately I didn't qualify. Now they are begging for young people to become apprentices. So sad the school counselors for many decades have discouraged students from going into the skilled trades. There is a tremendous shortage of skilled labor today for this very reason. It is an honorable profession and everyone in the business should be proud to be involved.
You’re a natural born teacher. You explained the different voltages very clearly. Thank you!
Being a non electrician it was a little confusing however I've always wondered where these numbers came from. This was an excellent topic to cover. I did learn a lot from it. Saving this video for future reference. Thanks for taking all your personal time to educate us, truly appreciated.
The answer is phase angle, and it requires a lot more explanation than I can put in a YT comment lol.
The main thing is you have a crap electrical system in the USA and had it been designed properly from the outset you wouldn't need all these different voltages.
You only need one voltage, one voltage on the income supply.
That's the phase voltage. A single voltage. Then by virtue of the fact you could supply multiple phases at that voltage, you then end up with a second voltage which is the line voltage which is higher.
That's all you need is a single supply voltage. But you haven't got that.
You've got over 50 different types of receptacles and matching plugs to handle all the different voltages and current ratings. It's a complete and utter mess. Overly complex for no good reason or benefit.
And no one in the government over the decades has had the balls to sort it out.
Delta connected secondary service (customer connections) are no longer offered by most utilities. Some remain in large industrial systems, but are no longer installed.
Three phase 120/208 volt distribution is what’s normally provided to apartment buildings, hotels, and businesses. Larger industrial customers , high rise office buildings etc have 277/480 volt service and have step down transformers to produce 120/208 volt.
Most low voltage three phase motors are rated 208-230/460 meaning they can run on 208 volts, 240 volts or 480 volts.
Single phase motors are generally rated 200-230 volts so operation on either 208 volts or 240 volts is acceptable.
We also, in this canadian province don't use 277/480 that much. Almost always 347/600, or 120/208 . Seen some 277/480 in a few older 60s buildings. But very rare still here.
No deltas either..since the 50s probably.
@@tripplefives1402 ✅ also allows more flexibility..
Not true in my area ...
@@tays8306 lots of delta in Canada. I have worked on many wye start delta run motors.
@@millwrightrick1
Depends on province. There is a few hanging around. But all the new installations we do are almost always 347/600v wye
I have seen a 762 volt system in an oilfield before. Phase to neutral was 480 but line to line was 762. This was a rare system that I am sure is obsolete by now.....Great video by the way!
Dustin... I've been an electrician for just about 20yrs and I'm glad to learn something new or be reminded of how things works. I've watched several of your videos and have certainly learned things. Anyone who tells me that I should know everything about the trade as a master electrician is just ignorant. Yes I'm a master electrician but I literally only get involved with low voltage work when I do side work. There's lots of things that I've simply never worked on or seen. That's how I found ur channel... Looking up something I was troubleshooting that I had never worked. I work on the utility side now and have since learned that under 2,400 volts is considered low voltage, medium voltage is 2,400v to 69,000v, and high voltage is anything above that (transmission). For years I referred to 50v or less as low voltage, 120/240 as medium, and 277/480 - 600v as high voltage. I've never worked with 600v systems and I never knew that there was such a thing as 347/600v. I appreciate your knowledge and explanations and refer people to ur channel including my own son who has started in the trade. Thanks.
Justin, you are the best , I’m so glad I found your channel…
OMG. In 14 minutes, You have explained what I had to learn on my own 50 years ago. It took me a whole lot longer than 14 minutes. And there was no such thing as 5v and 12v lighting controls, etc. Thank You !!
Automotive lighting control is 12v...
@@unhingedwilly7415 , that's true, but 12 v auto wiring for lights is not normally used in residences, commercial, nor industrial projects.
@@bruceb3786 actually, there is 12v lighting controls and systems. some smaller lights use 12vac (under-counter lights, garden lights, some track lights). it is rare to see 5vac but there can be 8vac for older doorbells
PLC CONTROLS ARE 12 V. & 24 V.and Fiberoptic here where I work
AND MOST FIELD DEVICES ARE 120
ALL MOTORS WE GOT ARE 480V.
AND SOME 4160 VOLTS ,
BUT PLC'S ARE 12 V. & 24 V.
An Fiberoptic from control room to mcc where PLC CONTROLS are located .
Awesome bro, I’m a maintenance technician who does a lot of electrical related stuff; whether it be lighting repairs, or new installations, or repairs and replacements on motors and machinery. I went to a vocational school to learn electrical and it’s cool to be be able to come to your vids and be able to refresh a bit
One way of avoiding frying your appliances or motors is to check the voltage using your multimeter before you hardwire in or plug in your new device. Absolutely great video though.
I run into the center ground delta all the time in my area (northern PA) I work in a lot of hospitals, schools, and restaurants where we have to be aware of that wild leg but I have never seen it marked even though it really should be. Also I love your channel, I am HVAC/R tech and due to my job (I fix restaurant equipment and HVAC) I find myself needed to know a lot more about electrical than your average HVAC tech and your channel has helped a lot.
Thank you for this video, I love this style content and how you explain things is fairly easy to understand. I’m almost into my second year in the apprenticeship and you have explained so much about transformers and systems that I haven’t understood for my previous time. Thanks man, I really appreciate this video.
Great channel. Practical bits - well explained - very clear. I wish more of us (engineers) had the practical sense of electronics. There's not enough mixing of the theoretical people with the practical get-it-done people these days. That mixing would benefit both groups.
You get a lot of practical and theoretical in construction. It just happens after the contracts are signed. What I don’t get is, somehow someway, the engineer of record is never wrong. 😂
I used to be an aircraft electrician in the Navy. Now I'm a Locomotive electrician. Locomotives generate 1200 volts (dc) at 2400 amps (for 4400 hp). Paranoia is a healthy thing I always tell the Noobs...
Screw the lightning strike, you should have powered the DeLorean with this!
dont be such a wuss. its only a few amps
@@eddiew2325 2400 hundred of them . How 'bout you touch it first, I'll go second...hahaha
@@eddiew2325 you'd get fried into a new dimention bud LOL
Good points. It's not the bolts that kill you. It's the Amps. A Static discharge that shocks a person in their home, can be 100,000 volts. Luckily, it's very low amps. One half of an amp can kill.
Very well done!! Ive been an industrial engineer for the past 20++ years and always had a hard time explaining these concepts of how a transformer is tapped properly. That's why we are in such demand.
@13:40 I could never wrap my head around this until I took trigonometry in collage, then it all clicked.
How the amplitudes of each voltage sign wave is relative to one another throughout the A/C cycle just clicked in my mined.
Love this channel.
i like that you showed the corner grounded delta because it is a situation where a phase conductor can be a grounded conductor without being a "neutral"
Brad Lanier the grounded conductor is only a kludge to equalize manufacturing inequalities due to age or manufacturing mismatches in the coil windings and/or power delivery errors. In situations of utopian perfection, the potential would already be neutral or at least no current would flow through the grounded conductor.
I'm in high school and been watching your videos and they are excellent. They have gotten me interested in becoming an electrician.
Do you think you could do a video about switchboards or switchgear. What they are for, all the different components on them and what they do, and showing us one in real life. I've seen them whenever I pass by some buildings but I don't know anything about them. Thanks! Keep up the great work.
You might be interested in becoming a Lineman as well.
@@yolo_burrito Thank you very much, sir. Will do!
Definitely get ahold of your local IBEW if you wanna get in the trade.
Been an electrician for almost 5 years that’s the only way I’ve heard it explained that I understand
Real talk!
Wow
I thought he meant he's asked for an explaination and everyone told him they were an elwctrician for 5 years and that was the explaination.
@Walkr he might have been a helper on a romex crew for four years. Not much to understand wiring houses.
@Walkr why? There's multiple different types of electricians most residential and even most commercial electricians don't know anything about industrial. And vice-versa. Also we're in a new era of people who think because they do some electrical work they're a electrician and they don't even know how to use a code book and thats the problem.
48V is also a common low voltage in the IT world as it's the voltage used for PoE equipment.
Good explanation on how the voltages are derived. Was hoping for a bit more of a history lesson as to why the various service voltages and configurations were chosen and have fallen out of favor.
Makes sense. I always wondered how PoE stuff worked with such a low signal 😂
I know some Cisco stuff puts out 56v and with the voltage drop you get 48v at the end device.
Well done on your computations! I enjoyed learning the separation between voltages on single and three phase! Keep up the good work!
This is the best tutorial I have ever seen on this subject. Great job Dustin!
The Canadian medium voltage standard of 600/347V is becoming more and more popular in U.S. industrial facilities instead of 480/277V as it saves 20% of the wiring cost.
Thank you, I appreciate the time and the technical side of your explanation!! I hope more individuals your age continue to do well for all of us that are close to retiring! You are amazing!!
Btw my journeyman taught me all of these calculations a while ago and I thought I had a decent understanding of it but once you explained I feel like I get it way better now. Appreciate you Dustin.
The 208 high leg is engraved in my mind now. Few months back i was landing wires for 120v plug inside generator enclosure. Picked the first unused 20 amp breaker i came across, might have been in a hurry. Sent 208v and cooked a $600 battery maintainer. I’ll never forget again. On a different note can you do some videos on why you would use dc versus ac in some applications like motors, controls, etc? Love the videos man your a great teacher!
I do very little electrical nowadays but still watch the vids! This is one I'll need to watch again. THANKS!
I do a lot of low / mains rated projects, so thought I'd chuck some interesting insight into the common voltages here in the UK...
The ones I've come into regular tend to be:
Low voltage:
3.3, 10, 12, 143.7, 18, 20, 24, 36, 48, 96, 110 (both AC and DC)
Our line voltage is 240v 50Hz AC, and there are other line voltages that do pop up pretty commonly... Namely;
415 and 600v, which do pop up in industrial applications but not for residential or small-scale commercial supplies.
I went to community college for two years ,and My respect for you bro ,you know what you teaching,
I know that these videos take a lot of time and effort on your end Dustin, but being an apprentice,these videos you do help a lot understanding electrical. Thank you for taking the time to put these together! It would be awesome if you can do a voltage drop video and understand the NEC and like ampacity and things like that.
I am not an electrician , But I manage a computer datacenter and the areas you covered has helped me understand our facilities and power panels . Thank you for sharing.
Good video. Alot of professors can't explain it as clearly and simple as you. Great job!
When in doubt, get your meter out!
JAMES! Since the 70's ... zippp...
Oh yeah! I even have an old analog Simpson like I learned on way back in the 80's. Lol
@@bowmanbk1 d'oh!
Yep more accurate than the finger test.
Couldn’t be said enough!!!!!
Love the content, this video was good can you do a demonstration with wire colors and physical materials , would love to see this broken down barney style, thanks
"Thank you so much for this video! It really helped me understand the voltage system in North America. In Europe, it's much simpler - we only have 220 volts single-phase and a 3-phase system with 400 volts."
The 208/240 explanation came very handy for me at this precise moment. Thank you!
Now I am glad tho be an electrician in Europe where we have 230V(/400V) system everywhere. Small houses and huge industrial companies run on the same system
Some countries still have 230V three phase system. In France it's almost extinct, only found in some old factories with private transformer, but in Belgium and maybe other countries both 230 and 400V systems still coexists. Depending on the cities or the street you can have 1 or the 2 systems.
I was told it's a real pain in the ass for music festivals or concerts tours. Electricians often have to rewire the panels depending on the voltage
@@lionnelc13 Norway have a lot of 230V IT/TT (Delta configuration) , but greenfield construction is with 400V TN (Y configuration).
A lot of old houses or small apartment only have one of the phases into the building, so unless you have a Renault Zoe, you won't notice it.
@
Simon Schertler yes, i'm glad that i'm an electrician in Germany with the 230V (/ 400V) system. only the plugs schould be the same across europe (the world. i think, the poland has the best plug: germen plug whit a ground pin).
@ Thank God for switch mode power supplies, and variable frequency drives.
In Amsterdam are parts with the old system with 2 fases, each 127 VAC. Making the 220 VAC between those fases. 127 x sqr(3) = 220 VAC
Now many countries in europe have 230 VAC and maby in the future 240 VAC. More voltage, so we can deliver more power through the same wires. The current determents the wire gauge, so to get more power (P=UxI) we're getting higher voltages.
Same for the higher voltages, 380 VAC come from 220 x sqr(3) and the newer 400 VAC comes from 230 x sqr(3).
4:40 That explained the 208/240 and also why some 3 phase have neutrals. Thanks!
Neutrals for anything with lights as a rule of thumb I always understood
Very well spoken video. Love that I made a comment asking this exact thing and he made a video on it 😁👍🏻 thanks, clears things up for a guy.
I love this Channel I’m constantly learning you my friend are a great teacher 👍🏾
Powerful lesson, I got a charge out of it.
I see watt you did there
There were times that even you looked confused trying to explain
A good thing that the UK is much simpler
The consumer side of the transformer it star, doesn't matter what application
L-N is 240V, L-L is 415, yep, it's that simple
For a treet, they drop a live and neutral in rotation to each house, house 1 gets L1, house 2 gets L2, house 3 gets L3, house 4 gets L1 etc.
3 phase is generally only used in commercial properties, they only need one 3 phase supply, and can take single phase supplies from that 3 phase, usually splitting loads to keep the phases balanced (a large room may have 3 sets of lights, one on each phase)
Motors can be wired as star or delta, or even use star/delta start/run
Because we are all 240/415, our cables can be smaller, this saves on copper.
Great explanation! Thank you for sharing!
I’ve been a general electrician for 18 years now, you are doing a very good job with these videos!
Great job Dustin !!! My first experience with 277 was with a metal fish tape into a florescent light fixture., doubled over as the current went across my chest. #@%^&I* it hurt like HELL !!!
Mine was also a fluorescent light fixture. One of those "designer" ones hidden in a little alcove. Push in connector attached to the ballast disconnect plug came out and touched me, that was nicely grounded to the fixture chassis. Lit me up real good. arm hurt for a couple days for sure. thankfully didn't fall off the ladder because my buddy was holding it for me. Was comfortable with doing light fixture repairs hot before but, won't do that style again if it's 277
Most 3ph motors in the factory I worked at were 550. Had one wacky machine that had , I think, 308v motors. Machine had its own transformer in the control cabinet.
nailed it. 15 years in the biz and your helping me keep sharp.
As an electrician I commonly wire motors 120 , 230, 240, 277, 300, 480, 600, 1200, 1460 and up. Some are 200 amps some are as much as 5000 amps.
I wire and manage transformers that step up or step down in the ranges mentioned above as well as voltages of 5kv,11kv,22kv, 33kv, 45kv, 120kv ....
Low voltage
Intermediate voltage
HIGH VOLTAGE .
I am a seasoned electrician of 34 yrs and I enjoy how Dustin puts things in layman’s terms which is a gift and not easy to do! He did however forget to mention if your not a licensed electrician to stay away from higher voltages like 208, 277 and 480 volts. They all can kill you quite easily. Especially 480! Nasty! Don’t play around please if you aren’t a professional...keep up the great work Dustin!
Not bad man. Pretty good description on delta. There’s more into why there’s 208 but than we’re getting into engineering and graphs.
he could have just described it as vector math and leave it at that. for someone that might not know, it might have helped. other than that, very good description
I am not sure why this video popped up for me to watch since I primarily watch art and philosophy videos on TH-cam , but yay! I accidentally started doing electrical design 20 years ago for an MEP engineering firm and ran across my first 240v, high-leg delta system in an old building a couple of months ago. My PE gave me a quick explanation and told me to avoid putting any 120v circuits on the B phase. Your video totally cleared it up for me! Since I learned design by doing and without a formal education, I find these weird little gaps in my knowledge. I definitely plan to check out more of your videos. Thanks for doing these!
Good video. I work as an EE in the construction industry in NYC and we deal with 277/480, 120/208V only. Have never designed a 120/240V system yet thats what I have in my house. In terms of what this video is for, great explanations. The science behind it gets a bit complicated but good layman's explanation.
a wye transformer allows you to transmit high voltages with very little current, whereas the delta virtually does the opposite [allows high current]. such is why transmission lines ie high voltage use wye transformers. typical uses for delta transformers are for industrial uses, but again, they themselves are fed with wye transmission lines. Some deltas have a grounded lead in which they most definately require a ground fault detector/protection.
the possibilities are numerous ie wye-delta, wye-wye, delta-wye, delta-delta. each transformer has their own uses, step up, step down, isolation etc.
because i couldn't/wasnt able to adequately explain myself...please check out this guys vids for some relatively easy understanding[easy for me anyways] of what i'd already learned going through my 3 levels[in-school learning] as an apprentice.
th-cam.com/video/rEiukQLCVao/w-d-xo.html
the way "you" explained deriving something like 120/208 or 277/480 is "almost" factually wrong. i say almost because while it could be done your way, and in a few industrial settings it is, that is not how anyone ought to be doing it nowadays[safety reasons etc]. if you want one service and two different 'systems' of voltages, you'd keep your wye sourced power as your main and feed a secondary wye-delta transformer if you need high current and different voltage from your standard 120/208y main service.
K Hills bro, what are you rambling on about? Nothing he said in the video was incorrect. He wasn’t telling anyone how to “do” something. He was just explaining how the voltage numbers work out for different types of transformers.
i didnt want to bring it up, but "you" brought it out, ..:
i understand what he's talking about and trying to explain. but he couldnt have done it any worse than you calling out that "he" didnt do anything wrong. your obviously not versed or couldnt be, in the the electric arts lol..[sry for the pun]. i would not have shown or taught voltages "that" way[his way] because i know better and have a better understanding.
when i said i didnt want to bring this up, i meant this guy teaching it er..."elec u" etc doesnt have a very good understanding of how shit works. ie transformers. i wasnt trying to literally call him out, but i did leave a link to a guy's vid who knows fuck more than this guy.
lmao, sry, im being a bitcx. my grief is not with you, its with elec u. ive done calculations and such way back when and i remember my lectures etc when i was doing my level 2 and 3, and it annoys the hell out of me when i see :yes this could work; but it is almost never done and i could think and draw diagrams to more easily explain this crap.
mostly because i dont want people thinking they can just "tap-off" a 3 phase delta transformer no problem...lmfao!!
You have no idea what you are talking about. I am an electrical engineer. I design systems using a delta-delta and delt-wye every day. Why in the hell do you think a wye transformer allows you to transmit high voltages with very little current, but a delta doesn't? Have you ever taken an engineering power systems course? You are COMPLETELY wrong when you said, "a wye transformer allows you to transmit high voltages with very little current, whereas the delta virtually does the opposite [allows high current]. such is why transmission lines ie high voltage use wye transformers." Where in the hell did you learn this? Did you create this in your head or did some other dumb-ass tell you this?
Good Job explaining. As an electrician most of this was just taught and taken as fact. It wasn’t until much later at a Russell Electric School that the odd voltages were actually explained. In single phase the two legs are 180 degrees apart (sign wave) three phase are actually 120 degrees apart so the differential between legs will never be the sum of the different legs to neutral since one leg reaches the top of the voltage curve while either of the other legs at that instant has less potential related to neutral. That explains where we get 208 v 277 on 480 Volt systems and 2400 on 4160 volt systems.
If you don’t teach, you should. Your videos and your presentation are tremendous. I’ve dealt with DC my whole life in AG equipment and found your videos because I was curious about AC and home service. The way you explain and show things is as good or better than any class I ever took on DC.
Great explanation. Thanks again Dustin!
The 600Y/347 system is mainly used in Canada.
Jolyon Welsh we’re starting to get rid of 347... too many accidents
@@trezzer53 still very popular here in Canada. A lot of new jobs in Canada are still be specified as 347
c31979839 typically 347 is now used in underground parking lighting, luckily now lighting is 120v supply w 0-10v dimming systems which makes it a lot safer
@@Nick-bh1fy 347 volts is naturally a byproduct of the 600 volt Wye or star system. One almost only uses it out of convenience. There are times when you might have a 347 volt source nearby. And you would have to all the way on the other side of the building to find a suitable 120 volt source. It is typically used for industrial and commercial lighting in Canada.
We have 600,480, 347, and 277 all in the same shop.
And 10,000V input from the lines.
New to the electrical game watched most but not all your videos really enjoy the authenticity you bring wish more people would be teachers of the craft instead of worrying about what their gonna earn from it
#toeachoneteachone
Ohhhhhh boy...you just can't leave out the earnings! What with the overtime, the weekends, the holidays! Time and a half, the double time, the TRIPLE time! The call outs, the storms, the wind-sheild TIME!! And everyone's pal: UNCLE SAM will be riding shotgun...for heavens, * DONT LEAVE OUT WHAT YOU'LL BE EARNING!! 😘😜🙄
Excellent video. I took a code class taught by an inspector a while back and you did as good of a job explaining this, maybe better!
Thank you! Sometimes it gets a little confusing depending on what a person runs into. Helps clarify many questions.
-48VDC is extremely common in telco systems
And PoE (power over ethernet), and a lot of small-ish solar setups. (off-grid, RV, etc.)
52VDC in the newer systems?
With the 3 phase 4 wire delta system, the NEC requires you to write or put a warning label on the panel in question " Caution, B phase is 208 volts to neutral.".
Not the only label tho correct. High leg wild leg can be used too correct
Love your videos when i get around to watching them, thank you so much!
Excellent explanation. It all makes sense. Thank you so much.
Nice explanation!!!
I've herd it explained a million diffrent ways and this was the clearest so far...mike holt would be proud😁
Only one thing I need to know about electricity:
I ran across a high leg on a residential service upgrade. It was confusing because it was a house 🤔. Here I come to find back in the day it used to be a shoe repair shop with living quarters upstairs for the shopkeeper 😂. They actually ran 3 phase into neighborhoods for these small mom and pop shops! There were 2 separate services, single phase for the upstairs and 3 phase for the shop. And it was all still fuses! It was pretty scary looking actually 😂Luckily I checked the voltages before I hooked the service up LOL.
Great videos, thanks for breaking this all down for us
16V/24V also used in many thermostats for furnaces, etc.
NetworKing often converted from transformers with dual-input 240/120VAC primaries.
You should do a video specifically on high leg Delta
Wow - what a great explanation. Even as someone who has had to work around 3-phase equipment, I never understood this.
Good job Dustin. Great presentation
American electrical supplies are nuts, glad that in Europe we have a unified system .
220 to 250 depending on where you are, corner grounded delta are also present
You have 230/400 and 400/690
Europe isn't simpler, it's just different
Clear as mud😁 Brings me back to my lineman school days. God I hated math.
I think we can all agree math is definitely not fun, however please dont use one of The Lord Jesus' titles in vain.
@@kylelikeskjvbible that’s actually his sons name not one of his titles but I see your point.
That was a fantastic video, thank you! It really made things click for once!
In Serbia we use standard EU system. It is actually German standard and it is very neat and reliable. Street transformer is always in wye configuration. Central point is grounded and that is neutral comming from transformer. Between phases you get 400-420V, and between neutral and each phase 230-240v. It is safe. Nobody here is electrocuted, and every household has 3 phase system. It is very practic especially who has a workshop or other business requiring strong motors for woodcutting, or other appliences including electric heating that is allowed to consume 24kW of power per house. Every pole transformer here is rated for 250KVA, 400KVA, 630KVA and 1000KVA. I havent seen stronger than 1000. Great video, keep on going!
277 hurts a lot more
In philly we had a "two phase" system fora long time. There are still some two phase buildings around. to supply them from a three phase supply you use a transformer connection called a "Scott- T". You can also cheat a bit and run two phase motors off of the delta with the center tapped winding and getting 240/208 two phase. The phases on two phase are 90 degrees away from each other
I had an old instructor he said they called those open bank sytems. The way the xformer gets it voltage like delta and wye open bank was those
@@kennethdunklin278 The two-phase transformers weren't delta or wye. The phases were at 90 degrees and not 120 degrees. They were more like X or T connected. I know it's all strange unless you worked on the old Philadelphia systems and buildings. It was really a crappy system that Philadelphia adopted in the beginning of utility power and we were stuck with it for like 50 years or more.
"In the early days of electrical engineering, it was easier to analyze and design two-phase systems where the phases were completely separated.[4] It was not until the invention of the method of symmetrical components in 1918 that polyphase power systems had a convenient mathematical tool for describing unbalanced load cases."
en.wikipedia.org/wiki/Two-phase_electric_power
upload.wikimedia.org/wikipedia/commons/thumb/a/af/Scott-T.JPG/400px-Scott-T.JPG
I'm also pretty sure it's covered well in "American Electrician's Handbook" www.amazon.com/American-Electricians-Handbook-Sixteenth-ebook/dp/B00COKLSVO and in "Electrical Machines Drives and Power Systems" www.alibris.com/search/books/isbn/9780130824608?qwork=1985923
@@cindytepper8878 Do you know if loads were separated like power and lighting to balance loads or more like just stab them in and turn em on? Im sure like now days unbalance loads need a return but we havent always been on a grounded system. Early days I was taught used to be ungrounded.
@@cindytepper8878 Ok it is a different system than open bank and I see how they get the 90 degrees too. Literally a "T" thats cool. I could see it being assumed as a Wye or Star but its definitely not. Hell yea, thank you for sharing this.
@@kennethdunklin278 Here is one of the crazy transformer connections that was most common in Philly. It was 5 wire, 4 hots and a grounded neutral
qph.fs.quoracdn.net/main-qimg-061bc48b1f8cece814845f7359c0f25a
It was highly inefficient in it's use of conductor material. I'm having a hard time remembering how you got the load balanced on the primary 3 phase supply side of the transformer. It's been a long time since I've been involved in any 2 phase systems. I think the last one was an emergency generator for the Philly Youth Study Center (kid prison) and I remembering it being a nightmare. That had to be at least 20 years ago. I'm trying to remember the details
The high leg is so important to explain to apprentices and experienced electricians alike. I was completely unaware of it until one of the guys at my work described it to me when we were doing work in an old building. I am aware of at least one case where an apprentice turned professional overnight and decided to take on side work during his studies. He ruined a $3,000 commercial refrigerator running a dedicated receptacle feed and connecting it to the high leg.
I learn something new today. Thank you.
If you draw two 120V lines in two phase (180 degrees from each other), then visually measure peak to peak it will equal 240V. I think if you draw out a three phase (120 degrees) and visually measure across the peaks the most you can get is 208V. It helps to see why it is 208V because the peaks of each phase never fully line up like two phase does. That's why you can't get the full 240V in a three phase. I didn't know about the square root of 3 trick to find that number quickly. Nice tip!
You can get the full 240V three phase in a deta configuration, and the best of both worlds (kind of) with a center tap on one of the transformers to give 120/240V single phase just like you'd find in your home, the winding furthest away from the center tap is the ghastly 208V stinger leg, you are not permitted to use the stinger leg to neutral for running single phase 208V loads.
This is the exact reason why. Sqrt3 is useful for math and it comes from the RootMeanSquare (RMS) way of measuring AC voltage
If u see a panel with every 3rd breaker available. Good chance that’s ur high legs. Double check ur voltage
Not spare 120
All this 3phase stuff makes sense if u understand physics. And vectors
What's your vector, victor? Huh? Over. Huh?
Hahahahahah ....understand physics... you speak like a peasant
Good stuff, as an instructor you make it easier to understand. I looked through your uploads and did not see any on 240v. I am specifically interested in ; add a 240 to a sub panel for welder, the difference in wiring to sub vs main panel, why the white/ common is not used, and what happens if it is wired to the wrong buss... I have a couple of electrician books and have asked a few folks that supposedly are certified, but have gotten a little conflicting information and now I am majorly curious...
Get a copy of the latest NEC
Not being an electrician, but working with this stuff because of it was there. These explainations make it easier even after the fact . Commercial mall voltages and such. The high leg in 208, we called the stinger leg.
One thing I will say is you were demonstrating 277/480 on a delta connection rather than a wye.
Love the configurations, and the beard...keep it up bro...
Great Primer ! Helpful Thanks
Randomly I got your video, trust me I'm really stunned by the way u explain, now I got the concepts clearly since years struggling out of confusions
For those interested, the main reason power companies supply a 3 phase with 208 volt high leg is because they can bring good quality 3 phase power to a remote location(e.g. farm) using only two high voltage phases called V phase. Saves a LOT of money. As rural areas build up with new construction,both residential subdivisions and industry, it becomes more economically feasible for the power company to supply full three phase power. For that reason High Leg installations are slowly disappearing across the country but many still exist, so be careful out there.
Can you do a video on panels with high legs and how to place your Breakers in them for 208v and what's the high like for
It’s simple. On that system, every third position on the buss bar will be 208V to neutral/ground. The rest will be 120V to neutral/ground. Just use your multi-meter if you’re not sure. High leg is for equipment that requires or can use 208V.
@@RB-xv4si thank you
Only place I ever seen run on it was some of the equipment in older Dairy Queens
Bobcat Sterling I’ve never come across it in my life. Just heard it talked about all the time.
The high leg is supposed to be the red phase (B phase in USA and A phase in Canada - don't worry.) And, you are only allowed to use it in a three pole or two pole breaker, and never with a single pole breaker. There is a lot more math behind it, much more than a text comment with a sale to explain. (Look up open delta on Wikipedia and that my explain more, though I've not actually looked there for this info, as I learned this in my apprenticeship school.)
Very well described!
The only thing left out was phase angle relationship. I understand that's where the √ 3 comes from, but I'm not sure everyone else does.
An aside: While it has nothing to do with utility service, there is also 120/240 180° split phase with center neutral as produced by a generator.
Very good information! You are a very good instructor and explain things well.
24 v Heating and air-conditioning systems thermostats
That's the first thing that came to mind. (not just to the thermostat, but to control relays/contactors, too.)
You forgot my favorite low voltage: -48v. Yes, I have a favorite low voltage.
Where is -48v used typically? Never seen it.
@@jaythompson5102 All over telecommunications I believe. Power over Ethernet being where most people see it, but anything in a telecom rack has a good chance of running off it. Someone correct me if I'm wrong, I used to work at the phone company, but I wrangled bits, not amps.
Sean Reifschneider yep, I work with carrier cell equipment and -48 is still everywhere. ATT being the first to use it and still do.
Most industrial controls are 24VDC. Mainly because per nfpa70e its finger safe
Yes, telecommunication systems typically run on -48v to -52 dc. If you take a dc voltmeter and measure between the two wires on a land line coming from the phone company, you should see -52v dc.
Excellent explanation. Thank you. Very easy to follow the math.
Great explanation Dustin. Thanks.
Can you explain three phase 240 a bit better?
3 phase 240 is a delta low side, your not going to see it much at least in my area. They do it so they can center tap one side and get you 120v single phase. Most low voltage three phase you will see will be 208v, which is a wye configured transformer.
@@josephkordinak1591 thank you. I'm in the business of installing battery chargers and have ran into 240 3ph once in the last year but 208 a handful of times. Thank you for the explanation
Some power companies avoid a "wild leg" situation by only using the wye-delta bank for three phase. A separate (fourth) transformer is used to supply single phase.
I work in Utilities, we don't install a fourth transformer to provide a customer 3 phase and a single phase service. A bank with 3 transformers, we change the internal windings to achieve the desired voltages. For example, transformer 1 is (25KVA) in parallel, transformer 2 is in series (50KVA) and transformer 3 is in parallel (25KVA) giving the desired voltages of 120V/208V/240V. The size of the transformer for one is doubled to accommodate the additional single phase load.
I really like how you explain everything in a simple way. Thank you !
My question is. What is the wire color rule that I Have to follow in order to wire a plug connector from my 3 phase charger. I need to plug this to the wall and I have 3phase 240vac with a high leg 208vac
Thank you !!
I enjoy watching your videos. I find a different view or reference always helps improve the big picture. I think another point of reference to cover, or you may already have it somewhere, would be how the sine waves work. Oh and maybe point out just how important it is in ordering xformers, to qualify a Delta or Y. (personal experience)