Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

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

Search results for query: *

  1. wfowfo

    Losses in HV Transmission: How Far Can Power (Reasonably) Get Sent?

    I know this might be largely off topic, but I heard someone once discuss the "dangers" of extrememly long transmission lines when you began approaching the 1/4 wave length of the 60 hz frequency that would make the line essentially a 60 hz radio antenna. I don't have the expertise to comment.
  2. wfowfo

    Grounded vs ungrounded capacitor banks

    I should have been clearer in my question. As magoo2 states, the 97% PF is aimed at the transmission lines. In the ERCOT Deregulated market, this responsibility has been dumped onto the distribution utilities. The cap banks I was referring to are on 12.5Kv and 24.9 Kv grounded wye distribution...
  3. wfowfo

    Grounded vs ungrounded capacitor banks

    We are under the gun to conform with the new NERC power Factor requirements of 97%. This will involve the installation a many new cap banks. My problem is that we use the Cannon Technologies AMR system and have blocking units in the neutral of each bank to prevent the signal from being shunted...
  4. wfowfo

    Distribution Capacitor Bank

    Is it possible that you already have a capacitor bank on this lightly loaded line and one fuse is blown on it? The theory about a rolled phase might explain the bad Kvars, but your Kw would be equally out of wack.
  5. wfowfo

    Broad band over powerline

    They are talking full blown internet. The metering part is to encompass 15 minute interval data and real time pricing.
  6. wfowfo

    Broad band over powerline

    The Texas Public Utility Commision has recently approved a Smart Metering initiative that least two companies are trying to accommodate via BPL. My knowledge of the technology is limited, but I understand it involves a significant number of coupling capacitors to get the high frequency signal...
  7. wfowfo

    Transformer Impedance Mismatch in 3-Phase Transformer Bank

    Waross Quote: "Some time past, it was pointed out to me on this forum that the voltage drop of a transformer under normal loading was determined by the regulation, not the impedance." Do you happen to remember the thread this was discussed in? If not, would anyone care to summarize a brief...
  8. wfowfo

    What causes a 9th harmonic on the power line?

    We have two PLC AMR systems, but neither are close to this frequency. We can see the problem in the substation (although, strangely enough, there is no significant 3rd harmonic). The problem worsens the closer you get to the end of the line (some 5 miles away) at one particular phone company...
  9. wfowfo

    Effect of Lagging Power Factor

    The new NERC requirements are calling for Utilities to maintain 97% power factors at the substation power bank with penalties for those who don't comply. Even if you don't pay a penalty now, you will very shortly as the utilities cannot afford to eat the penalties.
  10. wfowfo

    Reclosers coordination

    Would the rest of your coordination allow you to go to a "C" curve on the down stream device? Equally sloppy (but I've used it when nothing else would work) is to go 1 & 3 on the downstream unit and 2 & 2 on the upstream.
  11. wfowfo

    What causes a 9th harmonic on the power line?

    My utility is trying to help the local phone company find the source of a 9th harmonic which is causing noise on their system. The area is almost exclusively rural load with two exceptions; a lot of pipelines in the area (cathodic protection) and one large pipeline pump (1200 Hp). We've ruled...
  12. wfowfo

    Transformer

    What kind of results did you get on the bushings?
  13. wfowfo

    Transformer Spill Containment

    Some states require it based on the gallons of oil at the facility.
  14. wfowfo

    Low confiability of transmision line

    Could contamination of the insulators be a problem? We have a serious buzzard problem where the roosting birds on the crossarm defecate all over the bells. We've mounted bird quards and have lessened the problem considerably.
  15. wfowfo

    Common causes of faults in power stations

    I don't have a table, but the the majority of our substation faults are animal related with snakes being the worst and birds second.
  16. wfowfo

    Utility distribution feeder reclosing timing

    We used to use longer reset times when we had to coordinate with induyction disc transformer relaying. We're getting away from that now. What I want to know is; what "reset" time do you use after a successful reclose for the 79 circuits to go back to a "normal" mode?
  17. wfowfo

    Sizing primary & secondary XFMR protection

    Out of curiousity, was the 12.5/4.16 Kv transformer a wye/wye or delta/wye?
  18. wfowfo

    Rescloser Settings

    You didn't say specifically what your application was, but since you said "recloser", I assume you are using it in a situation where you have transient faults (i.e.,a utility). We set ours to reset automatically upon successful reclose. If the device goes to lockout, the targets remain...
  19. wfowfo

    Solar Panel Power?

    Quote by Itsmoked: "By far the best way to save money on your energy bill is to turn things off!!" Although most people don't consider it an option, this is by far the best advice on the subject
  20. wfowfo

    High temperature compsite core transmission wire

    Our utility is under pressure from the State governing board to upgrade one of our transmission lines due to "contingency congestion restraints". Because of budgetary constraints, we would like to explore the use of the new "composite core" type conductors that would allow us to increase...
Back
Top