Our meter tests have three goals:
- Prove that the analog-to-digital converters inside the relay are working correctly.
- Prove that we’ve connected it correctly; so we’re not wasting time troubleshooting connections later.
- Prove that the relay’s frequency, phase rotation, CT ratios, and PT Ratios settings are consistent with the system.
Can a simple three-phase test prove all of this? Watch this video to find out.
Do you think an unbalanced three-phase test can meet all of our goals? Watch this video to find out.
This is the test procedure I use to make sure that I’ve met all of our goals.
There are plenty of other ways to meet all of our goals and you can create your own now so you know the strengths and weaknesses of the most common tests.
Open-Delta PTs and GE SR Relays
Watch this video to see how to perform a meter test with wye and open-delta PTs on a GE SR relay.
Modern relays can be set with Open-Delta or Wye PTs. We try some experiments to see what happens when we apply the wrong connections and voltages to both kinds of PT configurations; so you can see what it should look like when they’re right and wrong.
Watch these videos to see how to perform Meter Tests on protective relays from these manufacturers:
Valence Electrical Training Services is not endorsed, sponsored, or affiliated with any company, trademark, or owner of any trademarks presented in these videos. This material is intended for educational and informational purposes only and any use falls under the Fair Use Doctrine of Section 107 of the Copyright Act.
Click Here if You are testing a General Electric / GE / Multilin Relay
Modern relay software can also show phasor diagrams and we look at that procedure in this video.
Click Here if You are testing a Beckwith Electric Relay
Click Here if You are testing a Siemens Relay
Click Here if You are testing an ABB Relay
Click Here if You Want to See More Videos About This Topic
Watch these videos to see how to perform Meter Tests with Test-Sets from these manufacturers:
Valence Electrical Training Services is not endorsed, sponsored, or affiliated with any company, trademark, or owner of any trademarks presented in these videos. This material is intended for educational and informational purposes only and any use falls under the Fair Use Doctrine of Section 107 of the Copyright Act.
Click Here if You Use an Omicron Test-Set
Click Here if You Want to See More Videos About This Topic
Click “Mark Complete” below after watching the video so you can keep track of your progress.
Hi Chris,
Could you expand on the “Perform a Meter Test on GE UR Relays” video @ approx. 3.02 seconds of the video, how all of the voltages were lag (lagging VA) and all of the currents except IC were lagging VA? I thought ( and I learned this from your Phasors webinar) that once you picked a reference signal everything was then relative to that point. However, in the subject video, you said that IC was leading. I am not saying that its wrong, I am just trying to understand how and why.
Thanks,
Shaun
Thanks for your question, and telling me what video and the timestamp. I’m a little tired of hearing my own voice at this point 🙂
You are correct that everything is related to the reference signal, and that all angles lag in both GE angle systems. Once you have a reference, you should always use the words lead or lag when describing any angle reference to prevent confusion. For example:
I can say that the C phase voltage in the GE UR video is 240 degrees. The person I am talking to could interpret that as 240 degrees lag, or 240 degrees lead depending on the angle system they use. Or another way to describe that angle using specific angle systems is:
SEL/Omicron/Math = 120 degrees
GE SR/RTS/Megger = 240 degrees
Manta/Doble = 120 degrees
GE UR = -240 degrees
To describe the same angle in universal terms where we don’t have to use the same angle system, I could say:
The C-Phase voltage lags the reference voltage by 240 degrees. (If my put my finger just above the A phase voltage phasor and watch them rotate, A will cross my finger first,the B phase voltage will cross 120 degrees later (120 degrees lag) and the C phase phasor will cross 120 degrees after B (or 240 degrees lag after A)
I could also describe the C-Phase voltage as leading the reference voltage by 120 degrees. If I put my finger just below 0 degrees and watch the phasors rotate, the B- phase voltage will cross first, the C-phase voltage will cross 120 degrees later, and the A-Phase voltage will cross 120 degrees after C. The B-Phase voltage crossed my finger first, so it leads the A-Phase reference voltage by 240 degrees. The C-Phase voltage came next and it beat the A-phase voltage by 120 degrees, so it leads the A phase voltage by 120 degrees.
I hope that helps
SO IN THE FIRST MODULE U CONNECTED THE RELAY AND CHOSE 3 DIFFERENT CURRENT SMALL BIGGER AND BIGGEST HOWEVER YOU NOTICED THE RELAY WAS NOT READING CORRECTLY. THEN U SAID LET ME MAKE SOME CHANGES TO MY CONNECTIONS AND THEN THE RELAY READ CORRECTLY. YOU NEVER STATE WHAT CHANGES YOU MADE. WHAT DID U DO TO CORRECT THE SITUATION DIS U ROLL THE VOLTAGES DID YOU ROLL A CURRENT……WHAT?
Thanks for the question. Please give me a time-stamp to see what you are referring to.
SO FINALLY IN MY OPINION IF I DO THE STANDARD BALANCED THREE PHASE TEST AND ALL MY VALUES ARE GOOD “AND” I HAVE A 100% POSITIVE SEQUENCE VALUE AND NO NEGATIVE SEQUENCE I AM GOOD RIGHT END OF STORY. GOOD 3 PHASE BALANCE D VALUES ALL LOOK GOOD POWER VARS CURRENT VOLTS ETC. AND ALL POSITIVE SEQUENCE I AM DONE NO.
Thanks for reaching out with a question. The rest of the videos in this lesson show that no, you’re not done.
IN THE METERING VIDEO ON GE UR RELAYS YOUR INITIAL SETUP ON THE TEST SET HAD THE A B C PHASORS AT 0, -120 AND -240 RESPECTIVELY AND THE RELAY READ THEM THE SAME SO WHAT IS WRONG HERE. 0 IS WHERE A SHOULD BE, -120 IS WHERE B SHOULD BE AND -240 IS WHERE C SHOULD BE………NO
Thanks for reaching out, but I don’t understand the question. Please use time-stamps to help me find what you are looking for. The Manta initially displayed the positive angle system, which is different than the negative angle system the Ge UR relay uses. The Manta allowed me to use the GE UR angle system, and I changed it to show how you could compare apples to apples with a Manta. You can get more information about the different angle systems used in the relay testing world in Course 1-2: Phasor Diagrams for Relay Testers (4 NETA CTDs) .
IVE BEEN HAVING TROUBLE ALL CLASS SEEING THE SMALL PRINTS AND DIAGRAMS, TERMINAL NUMBERS ETC. ETC. I NEED A ZOOM TYPE FEATURE THAT ALLOWS ME TO SEE WHAT YOU ARE DOING OR WHAT TERMINAL NUMBERS ARE. IS THERE ANY SETTINGS CHANGE I CAN MAKE OR SOMETING OR A MAGNIFIER GLASS I CAN USE PLEASE
Vimeo is managing the video quality based on your internet connection. You can change the video quality settings for each video as shown in the HOW TO NAVIGATE THROUGH COURSES video on the help page https://valence.relaytraining.com/help/. However, if you increase the video quality with a poor internet connection, the video will likely stutter.
OK CURRENT CONFIGURATION FOR BECKWITH RELAYS EXAMPLE 1 FOLLOWING FLOW OF CURRENT FROM GROUND TO GENERATOR TO LOAD. OK UNDERSTOOD. IM PUZZLED WHY THE CT POLARITY WOULD BE TOWARD THE GENERATOR THIS IS COUNTER INTUITIVE TO ME. FURTHERMORE THE SECONDARY CURRENTS EXIT THE NON POLARITY SIDE OF THE CT STRAIGHT TO GROUND FOR ALL THREE PHASES . IT IS COUNTERINTUITIVE AND CONFUSING AS HELL TO RUN Ia, Ib, AND Ic TO GROUND AND OR THE POLARITY INPUT ON THE RELAY. ADDITIONALLY THE STATEMENT THAT WE WILL NOT CONCERN OURSELVES WITH THE CT POLARITIES JUST THE FLOW OF CURRENT IS ATERRIBLE STAEMENT, PLEASE!. YOU MUST CONSIDER BOTH. SO IN THE FIRST CT EXAMPLE WHY DRAW IT THAT WAY WITH THE CT POLARITY IN THE WRONG DIRECTION AND SOMEONE IS SUPPOSED TO LOOK AT THAT LOUSY CONFUSING DIAGRAM AND TOIL OVER WHERE TH GROUND CONNECTION IN THE CT SECONDRY CIRCUIT REALLY IS, WHERE ITS SHOWN OR ON THE POLARITY SIDE. TERRIBLE IN MY OPINION, PATHETIC AND SOMEONE SHOULD CALL IT OUT ON BECKWITH THATS JUST PLAIN LOUSY, CONFUCING AND UNNECESSARY.
I completely disagree. The Beckwith image shows customers that they don’t need to dig into their switchgear to physically change the CT to meet some arbitrary drawing’s polarity marks.
This is hands-on, 100%, the best drawing that shows how the polarity marks we use in North America to describe CT connections; and the Starpoint descriptions used in European-style relays, mean absolutley nothing once the CT polarity test is performed and shown to match the drawing.
The reason you find it confusing is that you are fixated on the polarity marks. The only thing that matters is:
1 – The current flows into the correct terminal number
2 – There is a return path back to the CT
3 – There is only one ground on the CT circuits.
Everything else is noise… as shown on the Beckwith drawing.
Megger SMRT or Megger MPRT
Thanks for the comment, but I don’t understand your …question??
Hi Chris, while doing phase sequence check with single phase injection or unbalanced 3 phase injection, how would you deal with relays that has low residual current setting, negative seq current protection or unbalanced current protection set in the relay. In my part of the world, zero seq current pickup is quite commonly set at 20-30% of the rated current.
The relay should be isolated from the power system when you are performing a meter test, so I just let it trip. If the outputs are hard-wired to the trip circuit and the circuit breaker is open, I just let it trip because the thing it’s tripping is already open.
Dear Chris, thanks for the reply. I was confused with the fact that measurement of the “power system” would continue even after the trip signal is issued as long as there’s input signal from the CTs and VTs. My question arises from being stuck with a live power system where the CTs & VTs are installed at the protected object. Thanks for waking me up.