ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

ECN Shout Chat
Top Posters(30 Days)
Admin 19
Recent Posts
NFPA stuff
by gfretwell. 03/28/17 08:08 PM
Anyone hiring inspectors?
by HotLine1. 03/27/17 08:03 AM
Old decora style outlets
by Admin. 03/25/17 11:40 AM
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
fuse rejectors
by HotLine1. 03/24/17 07:53 AM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,665 Are you busy
166,575 Re: Forum
160,753 Need opinion
Who's Online Now
2 registered members (gfretwell, SteveFehr), 62 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#66708 - 06/14/06 09:42 PM R, S, T ???  
master66  Offline
Joined: Apr 2002
Posts: 257
Masontown, PA, USA
I bought a new meter today that has rotation indication. I've had them before but never knew what the letters R, S & T stand for. I know the phases by A, B & C.

Work Gear for Electricians and the Trades

#66709 - 06/14/06 09:51 PM Re: R, S, T ???  
Larry Fine  Offline
Joined: Feb 2005
Posts: 693
Richmond, VA

*Read The Manual

Larry Fine
Fine Electric Co.

#66710 - 06/14/06 11:53 PM Re: R, S, T ???  
e57  Offline
Joined: May 2003
Posts: 2,876
ABC = RST just a different set of letters for a sequence, I'll make the assumption that this is a Hotek or Hioki meter? And will also assume that the leads are red-white-blue, instead of black-red-blue?

Japanese made? Nothing wrong with that, I believe it will have the international symbol for clock-wise, of an arrow going 'clock-wise'.....

Mark Heller
"Well - I oughta....." -Jackie Gleason

#66711 - 06/15/06 12:42 AM Re: R, S, T ???  
Trumpy  Offline

Joined: Jul 2002
Posts: 8,211
SI,New Zealand
I believe that RST is a European convention,
they also used to use UVW as well.
I don't know a whole lot about the origins, maybe someone like Pauluk can clarify this?.
[Linked Image]

Let's face it, these days if you're not young, you're old - Red Green grin

#66712 - 06/15/06 02:22 AM Re: R, S, T ???  
e57  Offline
Joined: May 2003
Posts: 2,876
Reminds me of that guy who wired a cord cap XYN, when it was suppossed to be XYZ. [Linked Image]

Mark Heller
"Well - I oughta....." -Jackie Gleason

#66713 - 06/15/06 05:39 AM Re: R, S, T ???  
Texas_Ranger  Offline
Joined: Dec 2001
Posts: 2,392
Vienna, Austria
That's old European designation. I believe the terminals of a motor leading directly to the windings were/are XYZ, the terminals fot the feeder are UVW, and going backwards in the alphabet, the terminals inside receptacles et cetera were named RST. Has been L1, L2 and L3 for some 20 years though, at least in Continental Europe. My school (built in 1975-1980) still has the old designations written everywhere. After all, it still has fuses instead of breakers too...

#66714 - 06/15/06 08:46 AM Re: R, S, T ???  
pauluk  Offline
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Yep, I remember seeing the RST designations on some older European equipment years ago. We never used that scheme in Britain: Everything was either A/B/C, L1/L2/L3, or R/Y/B, the latter being for our standard phase colors: red/yellow/blue.

#66715 - 06/16/06 04:23 PM Re: R, S, T ???  
Fred  Offline
Joined: Apr 2001
Posts: 449
Straughn, IN 47387
Check out an Ideal 61-521 phase rotation meter. Red, yellow and blue phase indicator lights are also marked R, S, T. I never did know what RST stood for.

#66716 - 06/16/06 06:10 PM Re: R, S, T ???  
Scott35  Offline

Broom Pusher and
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Larry Fine:



*Read The Manual

LOL!!! [Linked Image]

I remember it as:

"Read The Fu.... er... Funny,... ya that's it [Linked Image] Manual.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#66717 - 06/16/06 07:30 PM Re: R, S, T ???  
RODALCO  Offline
Joined: Dec 2005
Posts: 854
Titirangi, Akld, New Zealand
R, S, T are the older European indications for 3 Phase equipment.

RST are the 3Ø supply phases.
UVW is start, for star delta motor starting.
XYZ is run for polyphase motors.

Now been superseaded with L1, l2, L3

The product of rotation, excitation and flux produces electricty.

Page 1 of 2 1 2

Member Spotlight
Posts: 208
Joined: February 2013
Show All Member Profiles 

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.023s Queries: 15 (0.005s) Memory: 0.8166 MB (Peak: 0.9921 MB) Zlib enabled. Server Time: 2017-03-29 01:23:23 UTC