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Electronics => Beginners => Topic started by: Simon123 on March 28, 2014, 01:24:14 pm

Title: R S T,L1 L2 L3, U V W
Post by: Simon123 on March 28, 2014, 01:24:14 pm
Hello!

I want to know, what RST in three phase system means?
Is it short for some words or something?

Thanks!
Title: Re: R S T,L1 L2 L3, U V W
Post by: madires on March 28, 2014, 01:50:09 pm
R-S-T is an old German naming convention for L1-L2-L3. It's not any abbreviation, just three consecutive letters. On some 3-phase motors you might also find U-V-W and X-Y-Z for the coils.
Title: Re: R S T,L1 L2 L3, U V W
Post by: Simon123 on March 28, 2014, 02:02:12 pm
Thanks madires.
Title: Re: R S T,L1 L2 L3, U V W
Post by: deth502 on March 28, 2014, 08:37:17 pm
yup, just arbitrary consecutive letters, just like naming them A-B-C
Title: Re: R S T,L1 L2 L3, U V W
Post by: Rory on March 28, 2014, 10:24:38 pm
Did you even bother doing a Google search before asking here?
Title: Re: R S T,L1 L2 L3, U V W
Post by: kingoftaurus on March 29, 2014, 02:01:32 am
Sometimes a human response is better.
Title: Re: R S T,L1 L2 L3, U V W
Post by: Kryoclasm on March 29, 2014, 04:16:55 am
R S T L N E      I'll take V W and a U Pat.




T _ R E E    _ _ _ S E    _ _ T _ R.
Title: Re: R S T,L1 L2 L3, U V W
Post by: kingoftaurus on March 29, 2014, 06:44:31 am
Quote from: Kryoclasm on March 29, 2014, 04:16:55 am
R S T L N E      I'll take V W and a U Pat.




T _ R E E    _ _ _ S E    _ _ T _ R.

I'd like to solve "Three Phase Motor"
Title: Re: R S T,L1 L2 L3, U V W
Post by: AKM on November 05, 2020, 07:55:53 pm
It means Reference (phase), secondary (phase) and tetriary (phase) in French.
Title: Re: R S T,L1 L2 L3, U V W
Post by: nightfire on November 05, 2020, 09:50:23 pm
Also in old systems (pre-1975) to be found is some old color coding: Yellow (L1), Green (L2) and Violet (L3), sometimes still used in high voltage installments.
In those old systems black and/or grey was the PE...
Title: Re: R S T,L1 L2 L3, U V W
Post by: Electro Fan on November 05, 2020, 10:17:50 pm
Quote from: AKM on November 05, 2020, 07:55:53 pm
It means Reference (phase), secondary (phase) and tetriary (phase) in French.

Is there a reference link for this definition? Thx
Title: Re: R S T,L1 L2 L3, U V W
Post by: Kjelt on November 05, 2020, 10:42:24 pm
Not sure about this but I recall and checked that one of the first inventors of AC current, Galileo Ferraris named the primary vector R, in his 1888 paper, probably after Rotazioni (Rotation).
Since I can not read Italian perhaps one of our Italian forum members would be kind enough to check.

If it was just a sequence of random characters they could have started with A,B,C  :)

http://ieeemilestones.ethw.org/images/a/a0/1-Galileo_Ferraris_Rotating-field--Rotazioni_Elettrodinamiche.pdf (http://ieeemilestones.ethw.org/images/a/a0/1-Galileo_Ferraris_Rotating-field--Rotazioni_Elettrodinamiche.pdf)


Edit: Or perhaps R is the standard mathematical name for a Rotation vector, a Euclidean vector whose direction is that of the axis of a rotation and magnitude is the angle of the rotation.
Perhaps someone can confirm this ?