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The X/R ratio of an air core reactor at this voltage, and 600 amp rating is about 60.Of course it can be higher.. Reference "A Practical Guide to Short-Circuit Calculations" by Conrad St. Pierre... chapter 5 pg 110 and page A-189. Jack

Mr. ScottyUK, Thanks for the question. And it is nice to know someone reads and pays attention. I myself can trace my linage to England in the 1600's. So here's a special to you. I did not make a mistake on the statiscal life and yes it is ~ 400 years. IEEE has made an analysis of the...

Mr. Bill, I should have been more specific about when the maximum force occurs---and thank you for noting I was not clear on that specific point. Actually there were several points which needed additional explation. Concerning when the maximum force occurs. The maximum force occurs when the...

Dan, Good for you. I will answer your question tomorrow or by Tuesday .What is the voltage of the caps and the voltage of the system and are these series reactors for a filter bank? If these caps are in series with a reactor what is the voltage rise on the cap bank? How are the caps grounded and...

Hey fellows, Here is the scoop. You say the transformer is loaded to 16.625 MVA. Here's the question. Is that the 24 hour RMS average?? If not, then that is not the loading!! Calculate the 24 hours RMS value and I'd bet my soul that it is less that 16.625. And who cares about starting a...

My lord. What are the enginners out there doing? Here are the fundamentals for calculating the energy losses, and efficiency of a transformer as a function of load, power factor, and X/R values. Please help me to understand why these question are being asked?? 1.Get the transformer test...

Well, this is a great question and let's start with the fundamentals. The question is where is the greatest force depends on the bus configuration. Surely this makes sense. For example a bus that is confiruged is a horizontal plane like ABC does not create the same force as a bus that has a...

SEFAILI, Unfortunately you are in way over your technical capabilities. Get some help!!There are more items to consider thant just the transformer differential settings.I'll bet you did not ask for the transformer technical data sheets or the technical information on the protection relays,the...

Mr.Rockman7892, I agree with wareagle-sounds like we both have been there befor. Do you honestly believe that serious electrical transients are coming form the system into your VFD units and causing problems??? There must be at least two transformers, (typical but it may be one) between you and...

The transformer connections were listed by group numbers and these number referred to the phase displacements. These were: Group 1(1)-zero degrees, clock hour number 0. Group 11(2)- 180 degrees displacement, clock hour number 6. Group 111(3)- minus 30 degrees disp., clock hour 1. Group 1V(4)-...

For jnims- I just want you know that was an excellent response. You get a star for me! great job.

I am going to answer this question on the basis that the items your interest relates to is Transient Stability of Power Systems where these terms are frequently encountered. If this is not what you had in mind it should still be useful since you have a system with local generation. This is from...

Part I continued Generator Rotor Ground Faults I note that I titled the initial post Generator Ground Faults and of course it should have been Generator Rotor Ground Faults since nothing in the material referred to any other winding except the rotor. When practical, it is standard practice to...

Sorry I hit the send button twice-one is edited and one is not

Generator Ground Faults- Part I I will have to write this in two parts since I will be leaving to take my son to his Lacrosse game before I can finish what I want to say. I assume the question is from someone outside the U.S. where the common termininology is to use earth faults rather than...

Generator Ground Faults- Part I I will have to write this in two parts since I will be leaving to take my son to his Lacrosse game before I can finish what I want to say. I assume the question is from someone outside the U.S. where the common termininology is to use earth faults rather than...

This is quick. The purpose of the bypass switch is to be able to start the motor should the electronic package fail.The larger the motor and the higher the voltage generally results in an important motor. Also the electronics in systems above 480 volts are not as reliable and you may need to...

Some additional information on lightning. Magnitude of Direct Strokes Recorded on Transmission Lines. Here is some additional information concerning ligntning strokes to transmission lines within the U.S. 1% of the strokes = or> than 111,000 amperes 5% of the strokes= or > than 63,000...

I suspect you have a classic case of the generator(s) having a third harmonic voltage content. You did not mention the ground connection of the damaged transformers and I will assume it was also solidly grounded. Is this true? Let' examine some typical situations with round rotor and salient...

Some comments on Polarization Index. Background Electronic Polarization When atoms are placed in an electric field, the electrons are displaced toward the anode (positive) from their unstressed positions, and the nucleus is displaced toward the cathode (negative). Due to the much higher mass...