Protective Relay Test Set/Equipment 3

[JBlackEE]

I am looking into relay test equipment currently. Does anyone have any advise? I have looked at Omicron and Megger some. I really don't know where to start. What other manufacturers are good? I am looking at testing overcurrent, differential and distance relays (SEL) in substation and transmission stations.

Preferred manufacturer? Likes/dislikes of certain models? Features you really like? I don't want to lug around a bunch of boxes, but I also don't want a suitcase that I need a truck to haul. I'm early enough in my search I can still be that picky...

 

[racobb]

Have you looked at:
Multi-Amp
or
Programma

Alan

 

[racobb]

BTW....not sure who owns/sells the multi amp line these days, if anyone.

Alan

 

[oldfieldguy]

"Megger" has the former AVO line of test equipment. Also try Doble Engineering. I'm particularly fond of their equipment.

You're not going to haul around as much iron as the test sets of twenty years ago, but you're still going to have a pretty good load with the test sets plus a laptop.

Also, be advised that the current generation of solid-state test sets work well with current iterations of solid state microprocessor-based relays, but some sets have serious issues testing the older electromechanical relays you might find still in service in some venues.

Also, if you're fairly new to the game, you might need to know that having the test set is only part of the equation. Most test sets now team up with test automation software. You may need some training to use the software, particularly when you run up against some oddball relay or application.

And lastly, if this doesn't apply to you, then ignore it, but I've seen many a relay "tested" and left with incorrect settings (wrong file uploaded, etc.) or tested properly but the relay or its programming was incorrect for the application. Testing of system protection equipment is a broad field, and some horrible mistakes can be made.

old field guy

 

[MatthewJames]

I use the Megger MPRT which is very versatile but also pretty expensive. Basic relays can be taken care of with an old Multi-Amp "76" set of an SR 51. These rigs are tried and true. My megger has had to be serviced several times in a couple of years. You might be able to find this sort of thing on EBAY.

If you plan on testing complicated elements on SEL's, I think you ought to go with an MPRT or the Doble relay set.

 

[ScottyUK]

Another vote for Programma, although Omicron's gear looked impressive when they demo'd it to us a couple of years ago.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[DTR2011]

I have to say that after using OMICRON for years and then Doble for the past 2 weeks, OMICRON is far superior. Much better software.

If you are in the 5 amp CT market, it is Doble, Megger, OMICRON and SCM. The Programma does not have enough current.

Also don't be fooled by a list of templates, especially when considering digital relays. Every implementation of a digital relay requires a unique test plan that tests the unique settings. When I test a relay I want to be sure that it operates as the protection scheme is designed, not how a template that changes the settings of the relay to facilitate testing does it.

 

[ScottyUK]

Hi smallgreek,

I'n curious - does that remark relate to the Sverker or Freja set? The Sverker has generally been ok so far, but some relays are much more demanding of the test set than others.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[JBlackEE]

Great feedback so far. I have Omicorn and Megger both coming to do a demo.

A little more info on what I will be using it for... It will be 5A CT's. It will be mainly SEL 351, 551, 387, 587 implementing settings that I have created. I like using the I/O's a lot.

 

[marks1080]

I prefer using the Manta 5000 - by Manta Test Systems. It's about $75K or so I think but it's great. Three phase V&I out, lots of inputs/outputs and can be programmed. Shows the R/X diagram when testing distance elements. I find it better than the Megger or Omicron equivalents but they are also good.

It's worth checking out their web site -

http://www.mantatest.com/

 

[davidbeach]

I can understand testing elements on electromechanical relays, or when type testing a new numeric relay, but what, really, is the purpose of element testing of an in-service numeric relay?

As I see it, we need to move away from "relay" testing and begin to do "protection system" testing. On the list of things that can go wrong, failure of the relay to calculate all the elements correctly is about the bottom of the list of what I'm worried about when it comes time to test a protection system.

One significant problem with these test systems is that when all is said and done, what was tested isn't what's in service. I want to see testing done where the relay program is never touched during the testing. Then every type of event the relay program is intended to respond to should be fed into the relay and the entire system checked. Did the breaker open? Did it reclose? If current isn't removed in a timely fashion did a breaker failure trip happen? If fault current starts up again as fast as the breaker closes do you get an SOTF trip? Make the tests, look at the relay event reports, study the relay SER, know what happened and why, but don't change the relay settings. It's bad enough to have to use secondary injection, but at least there are then easy ways of checking that the relay is seeing the actual system currents and voltages (metering in the relay) once the testing is completed.

If the relay settings are changed, there is no way of knowing if the protection system functions as intended once the testing is completed.

 

[DTR2011]

Hi All-

#1 - The Programma Freja has 3x15 A currents or 1x45A. Not enough for many 50 elements, or close in fault simulations.

#2 - I would look for a test set that can deliver 6 currents as this is necessary to test a digital differential relay (assume delta / wye) - else you have to change the settings of the relay, which defeats the purpose of the test.

#3 - Routine tests of some kind are required by NERC. I don't believe NERC specifies exactly how these are to be done, but I do believe it is in the future that the settings can not be changed.

#4 - For commissioning / acceptance tests, it is best to explore the relay a bit in order to get a feel for how the elements work / interact. I have found countless errors during commissioning where the intended logic was not programmed properly, settings errors, etc.

#5 - Nearly all test sets offer the ability to play back a COMTRADE file. The source can be EMTP/ATP and I believe some coordination software. This is really the best way to test and most important, no settings are changed. As David said, play the fault and see what the relay does. It is also very efficient, as each fault is quick, thus a realistic series of tests can be performed in the time it takes to do element testing.

Again, relying on canned test templates really serves no purpose, as these mostly require remapping the relay logic.

Carefully designed (user created) templates that provide all the normal AC signals at appropriate magnitude / phase and frequency can be designed for pick up / timing and logic. No setting changes required. A good sequencer and ramping test module will provide this. Multiple I/O on the test set for simulating inputs to the relay and measuring the outputs are required.

BTW - For what it is, the Programma SVERKER is a great manual test set for single phase relays and general commissioning work.

 

[marks1080]

I notice no one else has mentioned the Manta. Has anyone else used their equipment?

 

[JBlackEE]

davidbeach:
When testing, we have everything run through test switches. This way we are testing the entire panel to ensure correct wiring as well as operation. We also test all trip signals to breakers. We don't want to trip the breaker a ton of times, so we test any outputs associated with trip and close to the breaker and then open the test switch and assure all necessary signals are going to the test switch. I never mess with the programming on the relay during commission testing. We will also trigger or send signals back on alarms from the transformer.

 

[marks1080]

My experience is that it is during commissioning when you find errors in programming/settings. I have had to change relay programming/settings before during commissioning, of course after taking the appropriate change control measures. The engineers responsible for creating the settings sit in a cushy office at head office so it's up to field people to fix their mistakes.

 

[davidbeach]

The engineers responsible for creating the settings sit in a cushy office at head office so it's up to field people to fix their mistakes.

That is an attitude that never gets anything fixed. There has to be a complete feed back loop so that the engineers doing the settings know what doesn't work in the field and can revise the settings to both "work" and accomplish the intended functions of the original program. I don't believe that the test personnel should be changing things willy-nilly in the field, but rather that the whole team should work together to solve the problem.

 

[marks1080]

I said what I said with no attitude at all. More often than not incorrect settings get released. It is the fields responsibility (as laid out in our job description) to catch these. Also, I did mention 'change control' which does imply that there is communication between both groups on this. I am also a field engineer, not a maintenance or test technician. It is my responsibility to question and test everything that I put into service. If anything the head office engineers depend on people like me to ratify their work. I also do not believe I implied that I would ever change protection settings 'willy-nilly'.

 

[marks1080]

Also, it should be mentioned that testing numerical relays is very important. Do not always assume that they will work as some excel sheet tells you they should. Aside from other reasons mentioned here you need to be aware that these relays can be loaded with multiple settings groups. Say what you will about knowing what settings group should or shouldn't be loaded at anyone time but the things I've seen would make me want to test and test and test again.

Bottom line: Test all your relays. Fully. Completely.

 

[catserveng]

I'll second the Manta, it's been very good and we do a lot of SEL relays, we use the RTS Software, I don't do much relay testing, but I do use the Manta to verify installations and bench check relays and devices, like the fact I don't need a laptop to perform most of the functions.

I also liked the smaller Omicron 156 when I traveled a lot, was handy and very portable and did everything I asked of it. Had some short coming our relay test guys didn't like but I never got the details.

Mike L.

Mike L

 

[slavag]

Hi,
Im with davidbeach:
As I see it, we need to move away from "relay" testing and begin to do "protection system" testing.

STAR David.

Best Regards.
Slava.