Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: powercam
  • Content: Threads
  • Order by date
  1. powercam

    current transformers

    hi, the use of class x, p, t CT's for unit protection is what is normally recommended, were we can specify what knee point is wanted etc... what are the implications when we use class 5P or 10P ct's for unit protection. will the ct's satuarate more easily? are these types normally used for unit...
  2. powercam

    protection drawings standards

    hi i want to find out if there is a specific standard when it comes to duplicate protection. when wiring two differnet protection relays for a transmission bay, should the tripping circuit for the trip coils be seperated. i know that in my experience when we have 2 distance relays they are...
  3. powercam

    distance schemes

    hi people can a single distance relay be used to provide permissive under-reach or over-reach protection? from what i understand there must be 2 same relays across either end of the line to use POTT or PUTT. we have a 7sa512 and a REL521 on one end and then ONLY a REL 521 on the remote end, but...
  4. powercam

    earthing connections

    hi again, can the earth grid from a windfarm be connected to the substation earthgrid (10 km away ) via the cable earth sheaths? the fault current at the substation is 10kA, will the cable heat when a earthfault occurs? will the earth sheath handle 10 kA? the cable from the customer's windfarm...
  5. powercam

    islanding

    hi people.. i have two 110kv line bays at a loop station and this is in turn connected to a transformer that also feeds into our grid. the protection for the line bays is required to trip the transformer. i asked why the transformer needs to be tripped for a lin fault and the answer i got was...
  6. powercam

    voltage transformers being earthed

    hi ppl 2 questions 1.why is the white phase of a voltage transformer normally earthed? 2.I have a delta system. W-phase grounded, when I measure between phases I get 110V. What u are actually measuring is the voltage across a voltage coil. If I measure between the A-B = 110V, B-C = 110Vand...
  7. powercam

    batteries

    hi need to know if any utilities out there are using ni-cad batteries for substations that are 110kv and above. just to get a number ...i need to order batteries for all our subs but i am worried as to wheter this is tried and tested before, as i dont want to get caught out with problems later...
  8. powercam

    step and touch potential

    hi ppl. can step and touch be measured or tested. Also after the earth grid in contructed can we measure its resistance?
  9. powercam

    zero sequence impedance

    hi ... what is zero seq impeadance? were does it come from?

Part and Inventory Search