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  1. etgbccc2003

    Generators running on oil and gas

    Thanks guys. I've learnt a lot.
  2. etgbccc2003

    Difference Between RFCC and FCC

    Hi guys, Can anyone explain to me the differences of FCC and RFCC? What's the difference in feedstock and typical yields composite of various petroleum products (LPG, gasoline, naphtha, gasoil, etc)? Thanks.
  3. etgbccc2003

    Generators running on oil and gas

    Hi guys, How easy is it for power generators to switch between different feed? Example. Can a generator running on oil today be running on natural gas tomorrow? If yes, is it true that most large power plants have such generators that can switch fuel easily? Thanks.
  4. etgbccc2003

    Transformer Fault Analysis

    Thanks all for your valuable discussion with this topic.
  5. etgbccc2003

    Transformer Fault Analysis

    Also, the transformer is DY1 with NGR at the star point of secondary. There's no signs of damage in the primary linkbox. (Clean and dry) Thanks.
  6. etgbccc2003

    Transformer Fault Analysis

    sorry, As the event was deleted by someone, I couldn't get the ground fault values in time. This is a synchronous motor. Now, we may assume it as a fault at the bushing and assume that the current in the secondary CTs are due to motor contribution. However, what's the significance of the...
  7. etgbccc2003

    Transformer Fault Analysis

    rbulsara Red and yellow bushings porcelain craked. PT cables and fuses burnt. 51G picked up. 87T picked up. The transformer is a captive transformer running only 1 14000HP motor. Motor was running for many days before failure. Transformer windings, CT and PTs were not damaged. Motor meggar...
  8. etgbccc2003

    Transformer Fault Analysis

    stevenal, there isn't any previous failures before. However, I checked some sites saying that typically motor contribution is about 4 times the running current. My motor is running at >900A. Thus, I think the readings at the secondary CT might be only motor contribution and there could only...
  9. etgbccc2003

    Transformer Fault Analysis

    I think the CT saturation is unlikely as the fault current is only 3 times the CT current (1500). Could the current in the CT be due to motor contribution? How do we calculate motor contribution? Thanks.
  10. etgbccc2003

    Transformer Fault Analysis

    The CTs readings are IA = 1710 deg 0 IB = 2180 deg 142 IC = 1642 deg 241 Ia = 4267 deg 89 Ib = 3915 deg 215 Ic = 3586 deg 329 The transformer vector is Dy1 and when measured in GE 745's convention, there's a 180deg phase difference. Thus, it seems like the phase shift during flashover is...
  11. etgbccc2003

    Transformer Fault Analysis

    We have a transformer fault on a 33kV/6kV secondary linkbox of a 15MVA transformer. The event recorder at the differential protection (using GE multilin 745) shows that the secondary CTs shows about 4000A (not the same value for all 3 pahses but about 4000A while the primary CTs shows about...
  12. etgbccc2003

    Please help: Motor Constructionction NEMA Vs IEC

    Dear Sir, In IEC, there's a Ex 'n' and Ex 'e' construction. However, in NEMA, what's the equivalent? If we need to use a motor in class 1 division 2 area with possibility of hydrogen (Group B). How can we specify for a NEMA frame-size motor? Thanks. Regards etgbccc
  13. etgbccc2003

    What's the normal operating temperature of bearings?

    Thanks a lot. I was asking about anti-friction motors.
  14. etgbccc2003

    What's the normal operating temperature of bearings?

    Dear All, I have very little knowledge on bearings and would like to understand the above. Anyone kindly advice? Thanks.

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