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  • Users: devilskm
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  1. devilskm

    CT Ratio for Generator 51V Protection

    Please find the below link http://cid-0a0494be47f56008.photos.live.com/browse.aspx/Public There are two files, one which shows that the relay range limit is 5A. The second file is for Generator Curve. Please tell me that when we talk about setting the pick up at 150% -200%, is it after...
  2. devilskm

    CT Ratio for Generator 51V Protection

    I cannot set my relay at 150 to 200% of FLA because the max. set point for my relay is 5, which corresponds to 2000A. So I cannot go beyond that. What should I do?
  3. devilskm

    CT Ratio for Generator 51V Protection

    You mean that when I set the relay curve, I shall reduce the system nominal voltage for the curve less then the normal operating voltage?
  4. devilskm

    CT Ratio for Generator 51V Protection

    Emergency Diesel Generator 1000kVA, 0.38kV, FLA 1519Amps, CT Ratio 2000/5. As per IEEE C37.102, the pick-up for 51V shall be 150% of the generator FLA. In my case, the 150% of 1519 is 2279Amperes. Now this value is much higher the the CT installed. When I do the setting, I cannot set the pick-up...
  5. devilskm

    I am confused

    Thanks Scotty, I am working on your advise. So, which value of I shall be taken for ANSI function 51, 3P fault at that point or SLG fault at that point?
  6. devilskm

    I am confused

    The equation for calculating the time delay for NI type curve of any relay is T = AD / ((I/Ipu )^B – 1) And we know that for NI, we have A=0.14 and B= 0.02. Suppose I am using this curve for any Electrical Load having FLA of 100A. Setting the pick-up at 120% of FLA, Ipick-up will be 120A. From...
  7. devilskm

    Time Dial Setting

    How Important it is to do the relay settings manually before going for coordination on the software? Secondly, In one of the document, I have, they recommend the type of curve for the equipments, e.g for Transformer they recommend Very inverse Curve. Does it really depends on the type of...
  8. devilskm

    Relay Communication

    No school, but during my graduation, this was not the part of my curriculum.
  9. devilskm

    Relay Communication

    Any good reference about the Communication protocols for modern relays. I heard about RS232 and RS485. I need some literature about their applications, advantages and disadvantages.
  10. devilskm

    Time Dial Setting

    I am using VAMP-40 for Chiller feeder. The point which I want to make here, for chiller relay curve, the Time Dial is 3. The Low Voltage (380V) Switchgear for the chiller is fed by a Transformer (13.8kV/380V). For Pri and Sec side of this transformer, I am using VAMP-230. Since chiller is the...
  11. devilskm

    need some information

    Yes it is possible. Make sure all the generators have same terminal voltage, phase sequence, phase angle and frequency. You can use some small PLC to control all the generators as per your requirement.
  12. devilskm

    Time Dial Setting

    Greetings In the attached image I have set the time dial as 3 for the chiller relay curve. In Order to keep the Transformer curve (Transformer which is feeding this chiller), I have kept the time dial above the Chiller's. But the problem is that the settings I got from utility, the time dial is...

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