ES week 3

  1. List 5 distribution system characteristics
    shorter poles, poles are closer together (not longer than 50 miles), more equipment on poles, lines typically have aluminum conductors, structures are about 300 feet apart
  2. what is the primary objective of a distribution line
    is to receive electric power from the transmission system and distribute it to customer at voltage levels that can be utilized by the various types of customers
  3. what are the functions of a distribution line
    needs to function in a manner that results in the power being delivered safely with acceptable quality and reliability. Must have equipment to measure energy consumed by customers. Deliver power with a minimum of line loss.
  4. list the characteristics of a WYE designed system
    four wire, three phase with a neutral conductor, 2 voltage readings phase to phase and phase to ground
  5. what are the characteristics of a Delta system
    3 wire with no neutral, one voltage reading phase to phase
  6. main or feeder lines always begin at the _________ substation
  7. _______ lines branch of the main (feeder) lines
  8. Main lines have ______ conductors than tap lines
  9. tap lines can be _ _ or _ phases
    1, 2, 3
  10. system voltage is measured from
    phase to phase
  11. line voltage is measured from
    phase to ground
  12. what is a phase
    energized conductor
  13. what is primary
    high voltage portion of a distribution line
  14. what is secondary
    low voltage runs from pole to pole or padmount to pedestal
  15. what are services
    low voltage, runs from pole to customer
  16. what is the high voltage range for the primary distribution system
    2000v - 34500v
  17. what is the voltage range for services in the distribution system
    0 to 600 volts
  18. what is the acceptable voltage range at the customer's meter, obligated by utilities to provide
    114v - 126v or give or take 5%
  19. name four types (classification) of customers found in the electric utility industry
    residential, commercial, industrial, agricultural
  20. what two types of customers make up the bulk of customer base
    residential commercial
  21. phase to phase voltage =
    1.732 times phase to ground voltage
  22. phase to ground voltage =
    phase to phase divided by 1.732
  23. what is always three phase, starts at the station and radiates to the end of the line or tie to another circuit
    feeder maines
  24. star system
  25. tap two phases and the neutral to serve light three phase loads
    2 phase or v phase
  26. what 5 kinds of items would impact reliability
    size and type of structure, size and type of conductor, route of power line, location of protective equipment, overhead or underground
  27. 4 charateristics of tap lines
    can be one two or three phase or v phase, branch of feeder lines, smaller wire than feeder lines, can be looped fed from both directions
  28. what makes up a circuit
    main lines and tap lines
  29. primary overhead voltages
    2000v, to 34500v
  30. secondary overhead voltages, runs where
    0 to 600v, pole to pole
  31. overhead service voltages, runs where
    0 to 600 volts, runs from secondary pole to meter
  32. 2 parts of primary overhead
    surge arrestor, cut out
  33. 5 parts of secondary overhead
    transformer, secondary bus wires, 3 spool rack, open wire secondary, secondary pole
  34. 3 parts overhead service
    service drop, weather head, meter panel
  35. underground primary voltage range
    high voltage 2000v - 34500v
  36. underground secondary voltage, runs where
    0 to 600v runs to pad mount or pedestal or secondary box
  37. underground services voltage, runs where
    o to 600v secondary box or pedestal to customer meter
  38. 7 parts of underground primary
    cut out, surge arrestor, pot head, destination tags, primary conduit, load break elbow, pad mount transformer
  39. P.O.T. head
    primary outdoor termination
  40. 3 parts secondary underground
    secondary pedestal j box, secondary flood seals, secondary triplex
  41. 2 parts underground service
    customer meter, triplex service drop
  42. what is another function of the distribution system
    is to deliver power with a minimum of loss of power
  43. the number of customers on a circuit is determined by
    the density of the area, the type of customers, and the capability of the circuit.
  44. utilities are obligated to provide voltage at the meter in an
    acceptable range so that customer's equipment will run efficiently and not be damaged.
  45. with the transmission system, there is no neutral so one ____ to _____ voltage is used
    phase to phase
  46. common voltage levels in the united states are
    • 7200/12470
    • 7620/13200
    • 12000/20800
    • 14400/24500
    • 19900/34500
  47. how much more expensive is underground to install than overhead
    4 times
Card Set
ES week 3
NLC ES week 3