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Recent content by FEinTX

  1. FEinTX

    Electric Motor Use after 15 yrs Storage

    Not sure if it matters, but there's some more information about the motors in the Owner's Manual that I should have included: Traction Motor - 2400 rpm, Permanent Magnet, 2-pole Mower Motors - 3000 rpm, Permanent Magnet, 2- pole There are three 12V batteries in series, so these would be...
  2. FEinTX

    Electric Motor Use after 15 yrs Storage

    Question - Do I need to do anything special before applying power to electric motors that have not run since 1985? I am restoring my father's John Deere Electric 90 electric riding lawn mower which was built in 1972 and has been parked in a storage shed a LONG time. It ran up to that time, but...
  3. FEinTX

    Arc Flash Hazard? Yes or No?

    Breaker on the #4 tap is: ABB S4L 3 Pole Unit
  4. FEinTX

    Arc Flash Hazard? Yes or No?

    Yes, wind turbines. The pad-mount transformer is rated at 1850 KVA. High side is 34.5 KV with cable up to 1250 kcmil going to a 345 KV substation. Low side is 600 V with four DLO (Diesel Locomotive) cables (DLO262, I believe). So a fault at a turbine is fed not only from the substation, but...
  5. FEinTX

    Arc Flash Hazard? Yes or No?

    Figured out the attachment process... Here it is. -FEinTXhttp://files.engineering.com/getfile.aspx?folder=657cb6e1-1acd-453c-ab52-e3ac77c32f3f&file=20091117230726615.pdf
  6. FEinTX

    Arc Flash Hazard? Yes or No?

    Stevenal, Each leg of the #4 tap (this is 3-phase) is just 28" in length. See attached drawing. (If there are 2, use the 2nd one). FEinTX
  7. FEinTX

    Arc Flash Hazard? Yes or No?

    Thanks for all the great input! Yes, there are actually 2 issues that I'm looking for help with: (1) Will the smaller CB actually see 47 KA coming across the #4 wire? If so, what happens? Will it not open? Will it explode? (2) The arc flash incident energy for the line-side of the...
  8. FEinTX

    Arc Flash Hazard? Yes or No?

    According to our arc flash study, we have a maximum of 47,000 A available 3-phase fault current coming into a 600 V cabinet via some really big copper buswork and wires. It connects to a main circuit breaker which is rated at 50,000 A. However, there are also three 4 AWG wires that tap off the...
  9. FEinTX

    Door Blowing Open when PMT Fails

    Dave, The pics were of a new unit--just showing how the mechanism is designed. The failed units just have the rods bent back a couple inches though. If interested, I could post a pic of the bushing failure. These are a lot more interesting, but not really the topic I was chasing...
  10. FEinTX

    Door Blowing Open when PMT Fails

    Rbulsara - I do not have a picture of a blown out door, but nothing very dramatic. Often, no damage at all. Worst one was bowed and had to be sent back for repairs. We have had 6 failures (installed base is 180) where the bushing arced to the retainer plate (GND) on the high side, and yes...
  11. FEinTX

    Door Blowing Open when PMT Fails

    2nd Pichttp://files.engineering.com/getfile.aspx?folder=1a6aa762-9b75-474e-ba6a-c64d77771960&file=DSCF0630.jpg
  12. FEinTX

    Door Blowing Open when PMT Fails

    DPC, One difference between this and a 480V switchboard, PMT's are typically not behind security fences, or in mechanical rooms, or off-limits in some other way. There are smaller, lower voltage PMT's sitting in people's front yards as part of underground distribution systems. I've often seen...
  13. FEinTX

    Door Blowing Open when PMT Fails

    Question - Is it normal for a Pad-Mount Transformer to have doors blow open when there is an internal arc flash? Background + Equipment = 1.85 MVA transformer at 34.5 KV at a wind farm + Initial Electrical Failures - Elbow failure or Bushing failure + Typical Fault current 6-20 KA + Door...
  14. FEinTX

    Capacitor Bank Testing Question

    Hello, We are receiving a new substation at a wind farm equipped with capacitor banks. At a previous job, they used Joslyn zero voltage switches to engage the cap banks and during final testing a digital O-scope was used to confirm the timing was correct. 2 of the 6 switches had to be...
  15. FEinTX

    Trefoil Cable Configuration Question

    We are building a 34.5 KV collection system for a windfarm, and almost all the 3-phase cable is configured in trefoil. Occasionally, the installers make a mistake and in the middle of a circuit, one cable will jump through the other two. For example, you might have 1000' where the orientation...

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