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  1. 86ed

    Switchgear Replacement Planning

    If an EPC will be performing this turnkey work for you then you should be asking the EPC what contingency plans they have in place. If I were you, I'd be more interested in the contractual agreements regarding liquidates damages if the EPC is unable to execute the work in the allotted time...
  2. 86ed

    remote synchronization

    Odlanor, Can you send a single diagram of your power plant? Typically BSDG sets are connected to a MV (4.16kV, 6.6kV, etc.) within your power plant. In my experience I have seen BSDGs synchornized accross the MV incoming breaker which is connected to the grid via a UAT-->GSU transformer--PTs...
  3. 86ed

    Solar Storms

    mgtrp, Specail CTs and relays?? Do you mind sharing the wiring schematics/settings of how these will be implemented? Just curious and want to learn about these types of protection schemes. I worked in a utlity that is pretty far south so I haven't had the opportunity to see something like...
  4. 86ed

    Solar Storms

    It seems like geomagnetic storm damage to transformer assets is not a very big deal to utlities--at least as it pertains to equipment protection schemes. These HILF(high impact low frequency) events only justify (finacially) having the necessary operations response and grid management...
  5. 86ed

    Solar Storms

    This is a really interesting question. Does anybody know of a utility that actually implements GIC protection schemes like the ones in the attached .pdf? Where I work, I have never seen a customer specification for a GSU transformer requiring anything to protect against...
  6. 86ed

    E-Stop Push-Button Implementation ???

    Hello Everyone, I wanted to get some direction or possible opinions regarding the electrical implementation of “E-Stop” push-buttons used in process related systems (for example a pump that is performing process “X” which is being driven by a medium voltage motor fed from a MV controller). In...
  7. 86ed

    64REF CT implementation

    I have experienced this same issue in the past. Our GSU neutral bushing CT polarity was reversed. Double check all CT wiring if possible perform all CT polarity testing and finally double checking the CT starpoint direction settings in your relay.
  8. 86ed

    Why AC Power Distribution in Data Centers

    It's not a matter of DC vs. AC distribution. It's the generation of your power source. Do you expect to have the Data Center equipped with its own dedicated DC generation systems that would continuously feed the loads as well as the back up DC battery banks? No. This would be highly...
  9. 86ed

    Sudden Pressure Blocking for Through-faults

    I've seen this application SUGGESTED in a few relay manuals. Sudden pressure trip coming in via relay BIs and then blocking this trip using through fault detection within the relay. I've never actually seen this applied and I wouldn't recommend it. Will the transformer be experiencing a high...
  10. 86ed

    SPDT switching time for Sudden Pressure Relay

    stevenal, is correct. I was looking for the contact transfer time. However, I contacted Qualitrol and they said the two curves actually represent an operating region rather than the make vs. break actuating time curves. In the end…according to Qualitrol…2 cycles is the transfer time from...
  11. 86ed

    SPDT switching time for Sudden Pressure Relay

    Has anyone performed any testing on a Qualitrol 900 to determine the switching time for the Form-C? In other words, the time (ms) from breaking to making. Also, would this action be a function of the fault magnitude in terms of psi/sec? Not sure of the mechanics behind this contact actuating...
  12. 86ed

    Detecting underground cable theft

    These thieves sound pretty ballsy…..f.y.i some cities are beefing up scrap metal laws to prevent this sort of thing from happening. It sounds like the only solution to this problem is your field crew’s response time to an outage--try to catch them in the act.. Maybe, look into a fault location...
  13. 86ed

    Detecting underground cable theft

    Are these loose cable reels in a substation or actual energized cable (voltage? application?) and/or grounding cables? We're going to need a lot more information than what you have provided.
  14. 86ed

    profibus Control

    Both is possible. It all depends on the hardware/software capabilities of the DCS you are planning on using. However, it would probably be more elegant to stick with a single protocol for your protection & control system--if possible.
  15. 86ed

    profibus Control

    Hard wired start/stop commands is still and will continue to be the preferred method for breaker control. My company has started experimenting with IEC 61850 commands from our plant DCS to various IEDs. We would implement start/stop motor commands via IEC61850 before ever using/considering...
  16. 86ed

    Tie Breaker Closing Make Before Break

    rockman7892 Try looking into this system: http://www.energy.siemens.com/hq/en/power-distribution/highspeed-busbar-transfer-system/standard-solutions.htm I've seen this system in service and it is fairly elegant.
  17. 86ed

    Current Transformer Question

    20 years "operating"!! That's pretty funny.
  18. 86ed

    Replacement of OLTC

    Your question is too broad. What portion of the OLTC is being replaced? Any internal equipment replacement should involve the transformer vendor if possible.
  19. 86ed

    Relay Test Plans for Doble F6150 test set

    armysparky, Not to be negative and/or underestimate your abilities, but those aren't relays that a "real novice" should be testing. It sounds like these relays are going to be protecting some rather expensive equipment $$$ !! If I was the owner/customer of that plant, I would not allow a...
  20. 86ed

    Smart Grid

    BigInch…FYI… Some utilities actually have financial incentives for allowing the installation of load management systems in residential homes. LMS transceivers are provided by the utility and are installed in homes to enable the distribution dispatchers to reduce overall load at peak times by...
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