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 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: *

  1. dewone

    Electrical Cable Bend Radius

    The cable manufacture will give the min bend rad for the cable in the cut sheets. This varies per cable type, insulation, and thickness. I'd use the manufactures spec. If ABS has a more stringent spec use that. Again you will need to know cable material, and gauge if it has one.
  2. dewone

    MV(20kV) Vacuum circuit breaker and surge arrester

    I've seen them on the breaker, and on the load side in the cells.
  3. dewone

    breaker trip on ground fault

    How do you know the GF tripped you. On the first version of SST there are no indicators, on the second design there are indicators. Makes that an easy call. Is the SST a four wire, or the 3 wire.
  4. dewone

    Transformer Yoke and Frame

    The yoke connection can also be a high resistance grounding point, a neutral or four wire connection point, or simply grounded direct: low resistance ground. Depends on how your using the transformer.
  5. dewone

    High Voltage Connections for Dummies

    Hope this helps you figure the how. When you apply your stress cone or the build up of insulation. You first gap the cable by peeling the layers back down to the conductor. So from the end of the conductor where you crimp on the connection back, you peel so many inches of insulation to the semi...
  6. dewone

    TESTING of 1250kVA TRANSFORMER

    If it was properly stored. Oil sample, megger, turns ratio, and test any devices on the unit ie. pressure vacuum, oil level, temp gauge fan start, alarm, trip... Should give you a good indication of weather to energize. Had it been just shoved aside. The above plus Doble testing.
  7. dewone

    transformer mothball- keep in place for a few months

    Be sure to place a nitrogen blanket on the unit. Also keeps out moisture with out a heat source. For an extended period of out of service. Drain oil, and blanket with nitrogen. SphincterBoy has the other precaution covered ground all bushings.
  8. dewone

    Oil analysis results

    Maybe try a Fault metal test ASTM D-3635icp, and a Corrosive Sulfur test ASTM D-1275. Agree with the above retest DB on your own just to compare. Is this a conservitor type trans or sealed with a top air space.
  9. dewone

    Cleaning High Voltage Lightning Arresters

    For the tuff dirt. I use collinite No 240 with a scotch brite pad, then buff with clean rag to a sparkleing waxed finish. You can reach Collinite at 315-732-2282 (Happen to have can on my desk now)!
  10. dewone

    TRANSFOMRER TEMPERATURE READING VS TEMPERATURE RISE

    In most cases the alarm contacts are set @ 75C and shut off at 85C
  11. dewone

    Noisy Tranformer - Bad core laminations?

    Well alot good info has been discussed and without an electrical solution I suggest. Placing rubber under the transformer mounts to reduce the noise transfer to the floor that will help reduce the total amount of noise in the room.
  12. dewone

    Big motor starting

    Can the motor be Wye, Delta connected. Six leads in the condulet.
  13. dewone

    Utility distribution feeder reclosing timing

    Typical reclose times are like 7-10 seconds after trip. 3 Shots then lockout. Schemes I've seen anyway.
  14. dewone

    Acceptable Leakage current value at dielectric Withstand test

    Contact the cable manufacture for the amount of time per lengh, test voltage, and allowable leakage current.
  15. dewone

    Performing "retorque" of bolted electrical bus connections

    Checking the torque with a torque wrench should not yeild the tensil of the bolt any greater than the original torquewas set to by the manufacture. It should be re-torqued to the same value. You are only ensuring it hasn't vibrated loose. I can understand where someone over torqued a bolt and it...
  16. dewone

    Ka Rating on breakers

    I see so thats where they re-rate the breaker at a high Ka. 15 Kv ussually has around 7 3/8" gap or contact seperation. 5 Kv is around 5 3/4. Yet the 7.2 Kv is at the 7 3/8". Thank you, Dave DeWitt
  17. dewone

    Ka Rating on breakers

    Ever notice that the 7.2 KV breakers and the 15 KV breakers are the same except the nominal voltage is lowered and the Ka rating increased. Been wondering why it gets a higher Ka value?
  18. dewone

    Voltage Sensing Device Interlock

    Yes we do have these in the US. The equipment isn't US made but I have a customer with a simular set up in their High yard. 69 KV Siemens gear. Check with Siemens for info.
  19. dewone

    Info Needed on a Westinghouse OCB

    What doe's the nameplate have on it. In some cases the interuption rate is in the type, model, or style #. ie GE FK-255-500 = 500 MVA Interuption.
  20. dewone

    Current limiting breaker with si

    LionelHuzt Yes VK is Medium Voltage. The breaker times I stated earlier are for metal clad. Most instantaious curves even in molded case, insulted case are still around 0.01 to 0.05 sec's Have to admit that I haven't seen the curves for the Siemens CED6 yet.

Part and Inventory Search

Back
Top