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  1. vandal06

    Main Tie Main Closed Transition Re-Transfer

    Scotty, what kind of effort would be involved in increasing the fault bracing ratings of the switchgear and MCCs?
  2. vandal06

    Two job offers - decision - anyone work for a large global company?

    "B" threw up lots of red flags with them being weasel-ly with the job offer. I've had very bad first hand experience with job offers as vague as the one you are getting from "B" - don't fall for it.
  3. vandal06

    IEEE Std. C37.102-2006 tripping 63T same as 87T

    Do people actually specify separate 86 lockouts for each device? I've not seen it.
  4. vandal06

    ETAP Star View TCC kA

    When you run the kA update utility it populates the TCC clipping current field with the maximum fault current that device is subjected to, even if you are not developing a TCC for that worse case fault. This is one of the features I don't like about ETAP.
  5. vandal06

    University of Idaho M.Eng EE (Power Systems)

    Several of my coworkers are in various stages of the program and are happy with it. Myself, I have a BSEE from UIdaho and the quality of the professors (especially Law and Johnson) influenced my decision to go in to the power field. They are really great guys to work with and are always...
  6. vandal06

    Ground Fault Protection Question

    For a ground fault above 640A downstream of the feeders those feeders should operate first. Yes, all three poles will open for a fault even if it only involves one phase to ground, phase-to-phase, etc. Reason being is you don't want to single-phase any 3-phase loads downstream, and judging...
  7. vandal06

    Ground Fault Protection Question

    I'm not familiar with the fault currents available in your plant, I'm sure the engineer who produced the study (in Easypower, it looks like) ran those out. A ground fault of 700 A on the ASD40 AIR COMP would operate the breaker in the instantaneous band. It's hard to see but it's hidden behind...
  8. vandal06

    Cordinating Recloser loop schemes.

    Shot in the dark here, but maybe there is something for you in this SEL app guide. "AG2004-09 Minimize Distribution Outages With High-Speed Automatic Network Reconfiguration Using SEL-651R Advanced Recloser Controls" You can get it off the SEL website...
  9. vandal06

    Calculation result from ETAP, LL & LLG fault is higer 3phase fault

    My mistake, I thought the original poster was also asking about SLG faults.
  10. vandal06

    Calculation result from ETAP, LL & LLG fault is higer 3phase fault

    Scotty, wouldn't the 10A NGRs negate the low Z0 of the turbo-gens contributing to a SLG fault?
  11. vandal06

    GE Relay Unintentonal Settings Change

    Have you discussed this with GE?
  12. vandal06

    Microprocessor controlers in circuit breakers

    I can't offer much detail since I didn't have a heavy hand in it, but I do know several of my colleagues have grumbled about newer MV ABB metal-clad switchgear breakers we've used on projects, specifically problems with interfacing the trip coil monitors with protective relays. So if ABB says...
  13. vandal06

    Ground Fault setting guidelines using 50/5 CT's

    Rockman, for bullet point #1 - is the neutral of the feeder cable brought back separately or is it concentric?
  14. vandal06

    Ground Fault setting guidelines using 50/5 CT's

    I've used settings down to 10A before on a 50:5 CT with success. As mentioned you want to make sure this is above any expected loading imbalance.
  15. vandal06

    Transformer Differential Trips

    I'm glad you are getting a new relay. The event reporting capabilities will be of great value if/when the next trip occurs.
  16. vandal06

    CDEGs MALT and MALZ program

    It's been a long time but I remember using RESAP and MALZ when performing ground grid analyses.
  17. vandal06

    Transformer Differential Trips

    To expand on what David said, the newer relays with event targeting allow you to monitor in real time the operate and restraint quantities. Sometimes if the transformer is loaded lightly enough you won't know of a potential CT mis-wiring until it trips on an external event, like a feeder...
  18. vandal06

    Transformer Differential Trips

    My first thought would be to replace the relay with a unit that has event capturing. Regarding your latest trip, if it was inrush, there is a settings problem. I'm not familiar with the Basler unit but generally most are provided with harmonic blocking to restrain the differential elements on...
  19. vandal06

    Network share organization strategy?

    We use a revision control software package with a file structure similar to the one you posted. The files live on a central server and using the software you can "check out" individual files or even whole directories to perform work on. While checked-out the files/folders are marked as read...
  20. vandal06

    Transformer Inrush - Limited by short circuit availability?

    Healy, the system I'm studying has less fault current available than the 12xFLA at 0.1s for inrush. The transformer is rated at 25MVA, which gives a 12xFLA approximation of 1500A. The available fault current from the system is only 600A. waross, so with that in mind I'm looking at a 1st cycle...

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