Thanks All. I also made an interesting observation recently.
I was looking at a relay file of SR750 from GE and I noticed that ground element was disabled. After I did my research I found that SR750 has two CT ground inputs G3 H3 and G10 and H10.
Neutral elements in the relay file calculates...
Thanks Raghun
I guess you caught a nerve here that when currents are high residual scheme is the way to go and that is why I was seeing more and more residual schemes in the past on the primary side but could never got to see the actual explanation.
Your last comment
" speaking, the CT...
Hi gentleman,
I have done it many times but need a bit of scientific explanation to the approach I have taken.
I have a feeder entering a 2 MVA 13.8 kV transformer stepping it down to 4.16 kV Secondary which is resistance grounded with ground fault limited to 10 A NGR.
I need to have a...
Looks like they were not part of the enclosure because it was a retrofit and before that it had a oil circuit breaker in that enclosure.
But what ideas can be there to avoid some thing like this.
Is anti condensation heaters are the way to go. Could you kindly suggest some brand names that...
Hi All,
I have two completely unrelated questions and would appreciate your input. Ist topic is D20RTU and Second topic is AEG Vacuum type 38 kV outside metal class enclosed moisture isssue.
Q#1 A) What would be the purpose of a test relay in old
Datrac GE RTU ?
B) My setup has...
Hi,
I am sure you have seen it and done it all. I am not used to electromechanical relays and had my first encounter with them recently. I have a GE PJC32 relay
http://www.gedigitalenergy.com/app/ViewFiles.aspx?prod=pjc&type=3
It is a instantenous relay with a curve charc. Customer has a...
Rbulsara,
Please correct me, if I am wrong.
#1 In case of a med. voltage(13.8 or 4.16 kV) or low voltage, 3 Phase, 4 wire system, if I want to use a zero seq. CT, then the wires passing through CT will be ( Three Phases & Neutral and shield rerouted back through CT). Will imbalance operate...
Hi...
Thanks for your earlier valuable suggestions. A new entry into my work is to estimate cost involved in retrofiting medium voltage 13.8 kV oil breakers with vacuum breakers. Could you kindly advise me where I can find construction cost estimates for utility environment.
Thanks
Hi Jghrist,
In one of the last posts, you had commented
"Keep in mind that if you have R-Y-B East to West for a DYn1 transformer facing North and R-Y-B East to West for a DYn1 transformer facing South, you will have a 60° phase difference in the secondaries and you won't be able to get the...
Thanks davidbeach. Great advise.
In case of GE UR relays, their manual take you directly to Enervista Settings one by one and explain you the meaning of each settings and a brief example the way it should be.
I will be working with SEL 451 but There are four manuals for SEL 451 on website...
Hi All,
I just started a new position at a intermediate level in a electric utility. To my surprise the environment is completely different than I expected, it is probably more
cold hearted than a consulting environment but that is besides the point now I just have to deal with it for a better...
Could you please advise, where I can find some good reference on Phase displacment test. I want to find out if the Primary is leading or lagging the secondary,
Thanks
Hi,
I am supposed to work on a substation battery charger schematic and am working on getting some basic conceptual info.
In this system, when station service transformer supply is avilable, the recifier will supply the DC panel but as soon as the AC supply will be off, the batteries will...
Hi
I noticed in this post that a metering class cannot be used for protection. What problems could possibly either way if the CT's are replaced in applications.
Thanks
