# Phase Sequence Labeling



## splatz (May 23, 2015)

ABC or 123 

Reverse would be CBA or 321 

312 is the same as 123 - two follows one, three follows two, one follows three 
CAB is the same as ABC - likewise


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## Southeast Power (Jan 18, 2009)

We mark gear or enclosures with ABC CW or ABC CCW. 

We bought these for the guys, Much safer than having to remove dead fronts to connect to hot lugs:

Extech Non-Contact Phase Sequence Tester - PRT200


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## CoolWill (Jan 5, 2019)

Abc - cba


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## varmit (Apr 19, 2009)

CW = ABC, BCA, CAB
CCW - ACB, BAC, CBA

For CCW I normally do CBA.


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## 460 Delta (May 9, 2018)

Southeast Power said:


> We mark gear or enclosures with ABC CW or ABC CCW.
> 
> We bought these for the guys, Much safer than having to remove dead fronts to connect to hot lugs:
> 
> Extech Non-Contact Phase Sequence Tester - PRT200


Nice looking piece of gear, what is the price on a meter like that? I use a Knopp K-3 myself, it seems pretty bulletproof.


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## paulengr (Oct 8, 2017)

Standard rotation is a screwy thing. Even with protective relays some show it one way and some the other. Some engineers do a one of diagram the way math majors do it where "3 oclock" is 0 degrees and rotation is counterclockwise and others do it like a clock face with 0 at the top going clockwise. So one engineers ABC is another's CBA. Phase rotation meters are sometimes one way, sometimes the other. It's all relative and you just have to recognize which one you have when it matters.

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## Southeast Power (Jan 18, 2009)

460 Delta said:


> Nice looking piece of gear, what is the price on a meter like that? I use a Knopp K-3 myself, it seems pretty bulletproof.


I bought this larger sized one for about $150, they have a smaller one for 1/2 the price. Both on Amazon. 
I didn't know such a thing existed until the FPL lineman we were working with pulled one out. I ordered one the next day.


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## HertzHound (Jan 22, 2019)

Southeast Power said:


> We mark gear or enclosures with ABC CW or ABC CCW.
> 
> We bought these for the guys, Much safer than having to remove dead fronts to connect to hot lugs:
> 
> Extech Non-Contact Phase Sequence Tester - PRT200


I like that. Non contact. 

A few weeks ago most of the company had to sit through 8 hrs of arc flash safety training. They had a guy on video going through his story of his incident. He was using a phase rotation meter. They never really said what he did wrong. The guys here thought he had the Ideal that also checks motors when they aren’t hooked up. Maybe he hooked up the leads to the motor side of the tester and not the power side?

On a side note he was from Florida and hooking up a temporary generator to a store. Over 1,000amps from what I remember. They didn’t say the company. He was in a coma for weeks.


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## HertzHound (Jan 22, 2019)

460 Delta said:


> Nice looking piece of gear, what is the price on a meter like that? I use a Knopp K-3 myself, it seems pretty bulletproof.


I use the K-3 also. I bought it after an incident of changing a service on the sunny side of a building. Apparently my co-worker couldn’t see what lights were really lit. Especially when they Change when hooking up the last lead. Never have that problem with the K-3.


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## micromind (Aug 11, 2007)

I go with ABC or CBA. Less confusing that way.


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## Southeast Power (Jan 18, 2009)

HertzHound said:


> I like that. Non contact.
> 
> A few weeks ago most of the company had to sit through 8 hrs of arc flash safety training. They had a guy on video going through his story of his incident. He was using a phase rotation meter. They never really said what he did wrong. The guys here thought he had the Ideal that also checks motors when they aren’t hooked up. Maybe he hooked up the leads to the motor side of the tester and not the power side?
> 
> On a side note he was from Florida and hooking up a temporary generator to a store. Over 1,000amps from what I remember. They didn’t say the company. He was in a coma for weeks.


I saw that too. 
He did pull out the motor checker and it blew apart and burned him.
Seems as though he has an ongoing case, states he wasn’t properly trained.

Interesting, both the motor checker and the phase rotation meter come in the same bag if you buy the greenlee model. I’m sure they have a dozen different merchandised setups.

I wrote “not this one” on my motor checker. Sure enough, I grabbed it and connected it to check rotation. Snap,Crackle, Pop it went. No explosion. I walked it to the nearest trash can. Never again,


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## Bird dog (Oct 27, 2015)

I was on a job years ago that we had to repull feeders. We checked phase rotation in each panel initially & wrote it in the panel. When we reterminated, we followed the phase sequence.


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## paulengr (Oct 8, 2017)

Southeast Power said:


> I saw that too.
> 
> He did pull out the motor checker and it blew apart and burned him.
> 
> ...


I remember those. Just checked. They're discontinued. The manual says don't use the motor one in several places but everybody blew one out eventually. Bad design. It was CAT III 600 V on the live line one and even the new one is only CE rated. That means third party testing is optional. CE is not a recognized Listing mark in the US for good reason. Everything about the Greenlee testers (old and new) screams do not use. This is like an issue around 2001 in North Carolina and this is pretty much before Category ratings on a meter was a thing. The electricians wired up a 2400:480 delta delta transformer backwards. When they powered it up the first time everything seemed OK at first and surprisingly the 600 V insulation on the secondary side held. Then when one electrician tried to test output voltage is when they found the mistake. The meter ignited into an arc and the only thing to stop it was the primary side fuses which as usual for medium voltage were set very high.


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## JoeDirté (Jun 30, 2019)

Cba/abc


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## Jarp Habib (May 18, 2014)

Rotation is so messed up here, I've got to note L1-L2-L3 CW or CCW along with which phase is at which line terminal.

For example, at our primary ATS

Normal Line: Brown Orange Yellow
Generator Line: Purple Orange Brown
Load: Brown Yellow Orange

All tested L1-L2-L3 CCW. ABC or CBA isn't enough info, because which is your A phase now?? :vs_sob:


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## John R (Aug 20, 2019)

*John R retired electrician from Fed Gov*



Southeast Power said:


> We mark gear or enclosures with ABC CW or ABC CCW.
> 
> We bought these for the guys, Much safer than having to remove dead fronts to connect to hot lugs:
> 
> ...


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