Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep 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: *

  1. ASimmons23

    351-7 formula

    SEL 351S Manual, Page 3.59, talks about the power elements in the relay. I would start there and see if that helps you setup your logic and wordbits.
  2. ASimmons23

    MCC powering transformer aux

    Absolutely, as the other posters have said. The MCC is the structure for feeding local loads. I have always fed lighting transformers, battery chargers, UPS bypass transformers etc. from 480V MCC's. Just put in a correctly sized molded case circuit breaker, size the cable properly and you're set.
  3. ASimmons23

    Inrush limiting of across the line starts. Flywheel, etc??

    We use capacitor banks when starting large (14000HP+) motors in order to keep system voltage above 80% nominal. Injecting VARS to the system could decrease the "sag" the PC is seeing when the motors are starting.
  4. ASimmons23

    Fall-of-Potential vs. Clamp-on Ground Testing

    Thanks for the response zog, the other hurdle after deciding to use the clamp-on ground test is to make sure a thorough procedure is written/in place and the contractor understands how to properly conduct the test. For thise interested, I just received an email from an AEMC Instruments...
  5. ASimmons23

    Line Transfer Trip Criteria

    I am using 311L's for primary line differential protection (POTT) for 230kV, 69kV and 13.8kV transmission as well as a 351S for backup diff. scheme (DCB). For high speed transfer tripping, the 311L's with F.O. communications is the way to go.
  6. ASimmons23

    Fall-of-Potential vs. Clamp-on Ground Testing

    Thanks, those are the same conclusions I have come to. I was hoping I had missed a white paper (other than the one I referenced, which is put out by the same company selling the meter) or IEEE reference as it would be much easier to sell to the client who does not like deviating from the spec...
  7. ASimmons23

    Fall-of-Potential vs. Clamp-on Ground Testing

    Reference thread: thread238-231298 Good morning all, I wanted to get everyone's experience/opinion on using a clamp on meter instead of the traditional fall-of-potential test for ground testing. One of the general contractors is asking for a waiver to our current specs which state a...
  8. ASimmons23

    Overcoming Obstacles and....-Some Thoughts

    I find its much easier to get a job done when the politics/formalities are reduced in the workplace. I have the luxury of working with a small group schoolmates and other friendly people on a multi billion dollar construction job. Things get stressful and arguments ensue at times, but we can...
  9. ASimmons23

    Thinking about pursuing an M.B.A. and want to seek help from employer

    frv (Structural) 16 Aug 10 13:35 In my line of work, it's not common for employers to pay for education not directly related to the industry. You don't work for an EPC do you? ;)
  10. ASimmons23

    Would you go back to get an MBA, if you already MS?

    Greg you are absolutely right. Even if management is not in your career plan, engineers can really learn alot from an MBA program. One example that comes to mind is being able to speak to Management, using their language, in order to get what you want. An engineer's job is to design equipment...
  11. ASimmons23

    PE (Electrical Power Exam) Oct. 2010

    Batman, I found that the NCEES practice exam book (I believe it has a distribution station on the front) is VERY similar to the actual test as far as types of questions and difficulty. It would be very beneficial if you could work all 80 problems in that test as well as be able to navigate the...
  12. ASimmons23

    400V Supply on 460 V motor

    How about starting time? Anyone see an issue with a prolonged start? I'm thinking about protective devices tripping out to do starting current being applied longer than normal. (maybe not applicable on a 400V system...)
  13. ASimmons23

    Overload tripping

    Shozza, The relay isn't operating at 12-18 amps, the motor is drawing that much current. The capacitor is charged off the control voltage at the relay.
  14. ASimmons23

    Fault Analysis Help

    The three phase CT's are connected in a wye configuration with the residual current element (51N) on the neutral leg of this connection. It's not a calculation but more of a measurement and will pick up any phase current imbalance. I agree with JGHRIST that the imbalance most likely came from...
  15. ASimmons23

    NFPA 70E archflash

    We also use maintenance switches on each switchgear lineup which arms the 50 Elements of the main relays before any work is done on the gear. I highly recommend this solution opposed to not using an instantaneous element in situations where the inst. element interferes with downstream coordination.
  16. ASimmons23

    Enclosure Bonding

    Thanks for all your help, I think you are right, its a judgement call and field has decided to go ahead and bond the doors to the enclosure. Better to be safe than sorry.
  17. ASimmons23

    Enclosure Bonding

    That is the conclusion I came to as well, but if there are no devices mounted in the door (only the back panel of the enclosure) does the door need to be bonded anyway?
  18. ASimmons23

    Enclosure Bonding

    Quick question about bonding of enclosures: I have several control panels and junction boxes being installed in the field and while the enclosures are grounded to the system ground loop, the doors are not bonded to the enclosure. Does this pose a shock hazard? Also, is there any Code...
  19. ASimmons23

    A good place to find short-term (1-2 years) contracting jobs?

    I've had alot of interviews/calls from a headhunting agency, think energy group. You might google them and sign up to receive alerts about job postings. Many of the jobs are contracting positions that require travel. Like others have said, if you don't have alot of experience contracting jobs...
  20. ASimmons23

    Motor Enclosure Type FCXSD

    Actually, they is a plethora of equipment with that rating; switches, pushbuttons, circuit breakers, enclosures, motors, lights... A TEFC motor is considered good for a Group B (at least to the OSHA requirements I am working off of) because it is totally enclosed from the atmosphere thus...

Part and Inventory Search

Back
Top