Circuit Breaker Testing

[brian john]

Several issues.

We only do a couple of acceptance projects a year.
In 23-24 years I have only been called on it 6-10 times (rough estimate) and in most of those cases we were accepted.
I was NETA at one point (with a previous contractor).
I have worked with several NETA techs and was NOT all that impressed (also worked with some EXCELLENT techs). Being NETA certified proves nothing to me.
It cost money, FOR WHAT? In my case?
When I was a kid some of my friends were Scouts, I went Back packing and canoeing all the time and never had to were a funky outfit.

Never been an organizational type of guy.

BUT what the future holds, who knows if we decide it is a benefit we may join.

 

[mayanees]

TTR (Very important)

Zog,

I typically don't recommend TTR unless a transformer has been moved, or faulted in some way.
Do you agree with that approach?
What is your recommendation for frequency of TTR testing on dry-type and larger oil-filled transformers?

John M

 

[zog]

Zog,

I typically don't recommend TTR unless a transformer has been moved, or faulted in some way.
Do you agree with that approach?
What is your recommendation for frequency of TTR testing on dry-type and larger oil-filled transformers?

John M

No, TTR is an important test and should be done every time the transformer is tested. It only takes a few more minutes when doing all of the other tests so why not? Takes a little longer on oil filled because you test each tap setting.

 

[mayanees]

Thanks for all the responses guys, theres a lot of good information. I'm gonna spend some time on the NETA website and look into many of the tests that others have listed.

I suggest becoming an affiliate member for (I think) $75/year. You'll get a quarterly publication that's full of Electrical Testing topics that make for interesting EE reading. You'll also get discounts on NETA documents with the affiliate membership.

John M

 

[mull982]

, you can download the frequency of maintnence tests free at the NETA website www.netaworld.org

I downloaded this document. Very helpful. Where it differentiates mechanicl vs electrical testing I assume that the electrical testing are the obvious electrical tests and mechanical tests are all non-electrical tests such as operating breakers etc. What would a mechanicl test be for a electronic relay or transformer or cable where mechanical tests aren't so obvious.

,
Insulation resitance, including DAR and PI. 3 sets for each, H-LG, L-HG, and HL-G.
Winding resistance
Test all bolted connections with DLRO
TTR (Very important)

I'm assuming a TTR test is important to verify correct H-L ratios and therefore ensure correct voltage ratio at secondary.

Do you know where I can find more information on a DAR test which I am assuming is a Dielectric Absorbtion Ratio test?

I'm not sure what you mean whith the H-LG etc above. Are these how the high and low sides should be tested to ground for insulation tests?

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