Controls engineer here, frequently work in old, 'new' and mixed electrical panels. Also work with imported HVAC and other equipment that internally uses US/Chinese/god-only-knows-what colour schemes for it's power wiring. Mix that in with an assortment of colours used in the control and signal wiring and it can get real fun real quick!
I found that fascinating; thank you. One question that wasn't answered was "why three phases?" Why not four, or six? My assumption is that three gives satisfactory smoothness of power delivery and that the law of diminishing returns makes adding phases redundant. My assumption is probably wrong. I've been wrong before.
Nice vid. Oz uses red, white, blue for line and black for the neutral. Change occurred at the same time as green/yellow was confirmed as earth conductor.
Nice video! However, I think you missed out on mentioning one of the biggest benefits of 3-phase in a residential application; the ability to serve 3 high amp loads with a single 5 core cable. e.g. My Washing machine and tumble dryer used to be served off a single circuit. If they pulled their maximum load simultaneously, they'd trip the fuse. Annoyingly they were connected to a single phase in a 3-phase isolator, leaving the other 2 phases unused. I got a separate socket added and connected to another phase into the isolator, and never had any trips since. The other part of 3-phase that took me a long time to get my head around was that when multiple loads are on, only the "remainder" current is sent down the neutral.
In Germany the colors have also changed several times. In very old installations there was black phase and red PEN. Sometimes gray was used for N and red for PE. The reverse sequence has also been used by laypeople. Or was it an Englishman? Then new colors appeared at the beginning of the 1970s: phases of black, brown, black. Blue for neutral and yellow-green for PE. But it was often difficult to distinguish the black cable next to the brown cable from the black cable next to the blue one. Then came the uniform standard for Europe: brown, black, gray for the phases. Blue for N and yellow-green for PE. It's very difficult when you use all the colors in an old building just the way you like. Often the only solution is to completely rewire.
Switching from black-brown-black to brown-black-gray back and forth is really a pain, but replacing all wires isn't even possible if you don't want to rebuild the whole house. At least the old wires with the red PEN are getting rare and should always be replaced.
Guess we here in the states are kind of lucky as far as conductor colors. They have been pretty much static for decades. Single phase here is most always residential, we never have 3 phase in the ground or on the poles in residential areas. We have 120/240Vac at 60Hz with the colors being Black for L1, Red for L2, and White for Neutral. Green and sometimes bare is ground/ Earth. Commercial/ Industrial is 120/208Vac with Blue being added in for L3. We also have higher voltage for commercial 277/480Vac. Our colors change to allow for differentiation since the two coexist in commercial. Brown for L1, Orange for L2, Yellow for L3, and Gray for the Neutral. We step the 480Vac down to 208Vac for convenience outlets. Etc. Some services are 480 delta with no neutral, but most are Wye. At the research facility where I work as an Electrician, we have allot of European equipment installed so there is more than a passing familiarity with your standards required. We have alot of crossover in devices used for our equipment.
Many electricians improperly divide phases to integrated stove: cooking surface uses two phases and oven uses one phase. But cooking surface uses brown, black, blue and yellow-green wires; oven uses brown, blue and yellow-green wires - as result many electricians connect brown wire from oven to brown wire from line cable and leave grey wire without any connection, which causes circuit breaker to trip because brown wire carrying oven with cooking surface and grey wire is unloaded. It is useful to explain why brown wire from oven should be connected to grey wire from line cable in next video.
The EU was very much led by the UK in many fields of harmonisation, medicines, healthcare equipment as well as electrical standards and we were sorely and sadly missed post Brexit.
The CE marks that we used from the EU were a nightmare, because the 4 digit code could crossover. the biggest problem was in medical products. The CE code was also the accrediting organisation, not the product. We accepted CE-0086 for safety protective products, so we had to be careful. The most amusing one was condoms, where imported products were using the same CE as balloons, where a one in ten failure rate was acceptable. Endless jokes ensued about CE-0086. If you were a builder, you had the same code (safety) on your condom, your boots and your hard hat. Most people knew which one was which, but one site sent out a memo that condoms where not acceptable to wear as hard hats.
@@zaxmaxlax here is a full explanation, 3 phase systems are used as you can split loads across all 3 phases, use 3 phase motors which have less of a failure rate compared to single phase motors which uses a starter capacitor which fails. You can use 3 phase solar inverters to feed back 3 phases. You can find that 3 phase versions of items such as air conditioners will last longer as there is less components in use compared to single phase. Finally, 3 phase is just more versatile.
I remember hearing (years ago) that DC down a wire would cause electromigration on the wire and cause it to fail, but this wouldn't happen with AC, and that was one reason for using AC. That may be a load of rubbish - what do you think? If power is shared between countries via a DC link then I assume it is a load of rubbish! Also, it might be worth commenting that it's the magnitude of the current that causes loss in the cable, so if you can transmit the power at a much higher voltage, and thus at a much lower current, you significantly reduce the loss in the cable. I think that is the main benefit to transmitting at 10's of kilovolts - again, I'd love your thoughts on this. Cheers :)
It is a thing even in AC, if you see very old installations like 30+ yo, its only the phases that are corroded. That green stuff that comes from copper.
DNOs call the new colours by the old colours. Brown is red, white/yellow is black and so on. These habits have been passed down from the old boys down to the new lads and lasses
I didn't know that _we_ were responsible for the colour harmonisation. I'll add that to my argument book when someone moans about Europe. That said, my autistic brain likes colour and the older colours are growing on me for the sole reason of them looking nicer.
I wish I'd had you teaching Electrical Principles at college back in the mid-1990s - this is much more digestible!
Thanks for the fantastic comment 👍🏻
Controls engineer here, frequently work in old, 'new' and mixed electrical panels. Also work with imported HVAC and other equipment that internally uses US/Chinese/god-only-knows-what colour schemes for it's power wiring. Mix that in with an assortment of colours used in the control and signal wiring and it can get real fun real quick!
I found that fascinating; thank you.
One question that wasn't answered was "why three phases?" Why not four, or six? My assumption is that three gives satisfactory smoothness of power delivery and that the law of diminishing returns makes adding phases redundant.
My assumption is probably wrong. I've been wrong before.
And I was always told it was balanced.
Nice vid. Oz uses red, white, blue for line and black for the neutral. Change occurred at the same time as green/yellow was confirmed as earth conductor.
Nice video! However, I think you missed out on mentioning one of the biggest benefits of 3-phase in a residential application; the ability to serve 3 high amp loads with a single 5 core cable. e.g. My Washing machine and tumble dryer used to be served off a single circuit. If they pulled their maximum load simultaneously, they'd trip the fuse. Annoyingly they were connected to a single phase in a 3-phase isolator, leaving the other 2 phases unused. I got a separate socket added and connected to another phase into the isolator, and never had any trips since.
The other part of 3-phase that took me a long time to get my head around was that when multiple loads are on, only the "remainder" current is sent down the neutral.
An advantage of the old colours is that they were easier to distinguish in poor lighting.
In Germany the colors have also changed several times. In very old installations there was black phase and red PEN. Sometimes gray was used for N and red for PE. The reverse sequence has also been used by laypeople.
Or was it an Englishman?
Then new colors appeared at the beginning of the 1970s: phases of black, brown, black. Blue for neutral and yellow-green for PE. But it was often difficult to distinguish the black cable next to the brown cable from the black cable next to the blue one.
Then came the uniform standard for Europe: brown, black, gray for the phases. Blue for N and yellow-green for PE.
It's very difficult when you use all the colors in an old building just the way you like. Often the only solution is to completely rewire.
Switching from black-brown-black to brown-black-gray back and forth is really a pain, but replacing all wires isn't even possible if you don't want to rebuild the whole house.
At least the old wires with the red PEN are getting rare and should always be replaced.
Guess we here in the states are kind of lucky as far as conductor colors. They have been pretty much static for decades. Single phase here is most always residential, we never have 3 phase in the ground or on the poles in residential areas. We have 120/240Vac at 60Hz with the colors being Black for L1, Red for L2, and White for Neutral. Green and sometimes bare is ground/ Earth. Commercial/ Industrial is 120/208Vac with Blue being added in for L3. We also have higher voltage for commercial 277/480Vac. Our colors change to allow for differentiation since the two coexist in commercial. Brown for L1, Orange for L2, Yellow for L3, and Gray for the Neutral. We step the 480Vac down to 208Vac for convenience outlets. Etc. Some services are 480 delta with no neutral, but most are Wye. At the research facility where I work as an Electrician, we have allot of European equipment installed so there is more than a passing familiarity with your standards required. We have alot of crossover in devices used for our equipment.
Excellent video. Really good subject matter. Helpfull. Here is a merit.
Very good !
Thanks
Love this content
Thank you! 😃
Many electricians improperly divide phases to integrated stove: cooking surface uses two phases and oven uses one phase. But cooking surface uses brown, black, blue and yellow-green wires; oven uses brown, blue and yellow-green wires - as result many electricians connect brown wire from oven to brown wire from line cable and leave grey wire without any connection, which causes circuit breaker to trip because brown wire carrying oven with cooking surface and grey wire is unloaded.
It is useful to explain why brown wire from oven should be connected to grey wire from line cable in next video.
Great information. Not an electchicken but this was very helpful. Thank you.
The EU was very much led by the UK in many fields of harmonisation, medicines, healthcare equipment as well as electrical standards and we were sorely and sadly missed post Brexit.
The CE marks that we used from the EU were a nightmare, because the 4 digit code could crossover. the biggest problem was in medical products. The CE code was also the accrediting organisation, not the product.
We accepted CE-0086 for safety protective products, so we had to be careful.
The most amusing one was condoms, where imported products were using the same CE as balloons, where a one in ten failure rate was acceptable.
Endless jokes ensued about CE-0086. If you were a builder, you had the same code (safety) on your condom, your boots and your hard hat. Most people knew which one was which, but one site sent out a memo that condoms where not acceptable to wear as hard hats.
The reason for three phase is that it minimises the amount of copper needed to carry the power.
Thanks for commenting. 😊
Nope. The reason is because everything that produces AC electricity(except solar) relies on a 3 phase motor.
@@zaxmaxlax here is a full explanation, 3 phase systems are used as you can split loads across all 3 phases, use 3 phase motors which have less of a failure rate compared to single phase motors which uses a starter capacitor which fails.
You can use 3 phase solar inverters to feed back 3 phases.
You can find that 3 phase versions of items such as air conditioners will last longer as there is less components in use compared to single phase.
Finally, 3 phase is just more versatile.
I remember hearing (years ago) that DC down a wire would cause electromigration on the wire and cause it to fail, but this wouldn't happen with AC, and that was one reason for using AC. That may be a load of rubbish - what do you think? If power is shared between countries via a DC link then I assume it is a load of rubbish!
Also, it might be worth commenting that it's the magnitude of the current that causes loss in the cable, so if you can transmit the power at a much higher voltage, and thus at a much lower current, you significantly reduce the loss in the cable. I think that is the main benefit to transmitting at 10's of kilovolts - again, I'd love your thoughts on this. Cheers :)
It is a thing even in AC, if you see very old installations like 30+ yo, its only the phases that are corroded. That green stuff that comes from copper.
13:38 why my calculator gives a different result 23000 divided by 400 multiple by x3 =172.5
DNOs call the new colours by the old colours. Brown is red, white/yellow is black and so on. These habits have been passed down from the old boys down to the new lads and lasses
Germany have a long time 3 phase.
I didn't know that _we_ were responsible for the colour harmonisation. I'll add that to my argument book when someone moans about Europe. That said, my autistic brain likes colour and the older colours are growing on me for the sole reason of them looking nicer.
So glad I finished my scientific principles exam 2 hours ago… 😂
Good job!👍🏻
Are the brits finally getting 3 phase supply on regular homes? 😂