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2014-02-05 23:36:39

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  1. what is the industry standard for determining polarity by KVA rating and primary voltage
    200KVA and smaller with a primary rating of 8660V and below will be rated additive. all others transformers will be subtractive
  2. when facing a transformer with additive polarity, where is the X1 bushing in relation to the X2 bushing
    X1 is on right
  3. why is the nameplate considered the most important part of a transformer
    it provides technical information to the lineworker that can be used to safely install the transformer
  4. name 7 important items of information found on the nameplate of a transformer
    weight; primary voltage; secondary voltage; impedance; serial number; schematics; KVA rating
  5. what radiates heat from the transformer case into the atmosphere
    the circulation of insulating oil by heat is called convection
  6. how does the secondary coil become energized when the primary coil of a transformer is energized
    the process of induction
  7. transformers are referred to as
    machines with no moving parts
  8. name the three main internal components of a transformer
    core; windings; insulating fluid
  9. what four letters are used to designate the ends of the secondary windings of a typical overhead transformer providing 120v/240v
  10. when facing an overhead transformer where would you find the H1 bushing
    left side
  11. what protective devices does a CSP transformer have
    primary current limiting fuse; secondary bushing circuit breaker
  12. what is the order of secondary bushings on an additive transformer or an subtractive transformer
    • additive: X3, X2, X1
    • subtractive: X1,X2, X3
  13. when facing an overhead transformer where are the H1 and H2 bushings always located, weather conventional or CSP
    H1 left, H2 right
  14. what are two instances when you would operate the pressure relief valve on a transformer
    pop the top, pull the bayonet fuse on an underground transformer
  15. what do we call the X2 bushing on a transformer
  16. three types of underground transformers
    pad mount; vault; submersibles
  17. what is the primary bushings on a underground transformer labeled
    H1A, H1B
  18. what does the bayonet fuse de energize on an underground transformer
    secondary bushing
  19. when banking transformers together, what is the total rating of the bank
    equal to the sum of the individual transformer KVA rating
  20. what does the core of a transformer consist of
    thin lamination of grain oriented silicon steel rolled into layers with a coated with insulating material
  21. primary and secondary windings operated how; wire size
    primary induces voltage on the secondary, consists of smaller wire; secondary windings delivers the output voltage to the consumer consists of larger wire than primary windings
  22. acronym for paralleling transformers
    Alley Cat Bad Dog
  23. what type of oil is used in transformers
  24. when will the internal pressure release valve vent
    when the internal pressure reaches 10lbs
  25. what material is used for the windings of a transformer and why
    copper; low resistance and superb conductivity
  26. wires that connect externally and transmit power from the secondary bushing to the load
    Hot legs, X1 and X2
  27. a transformer has only one primary bushing, how do you connect the transformer
    phase to ground (WYE)
  28. which type of transformer is said to be the most versatile
    phase to phase or phase to neutral
  29. what is a WYE secondary voltage
  30. looking at the secondary windings as you are facing the transformer, how are they labeled
  31. why do we parallel secondarys
    to maximize KVA
  32. phase to ground connection is considered