Conduit bending

  1. Another method for laying out and forming a 90 degree bend with a hand bender, opposite the push through method, is called what? When using this method the take-up for the bending shoe is no longer a consideration. lab 1-4
    • Reverse method
    • Star method
  2. The arrow method is know as the ________ method and the reverse method is known as the ______ method when creating back to back 90's. lab 1-1
    • push through
    • reverse
  3. When completing a 3 bend back to back with a hand bender the First two bends are done facing which direction and which mark on the shoe? The third and last bend is made similarly how? lab 1-14
    The first two face the same direction with the arrow as your mark and the 3rd and last faces the opposite direction with the star mark.
  4. The distance between bends in a 3 bend saddle is determined by what formula?
    NJATC, Conduit Bending And Fabrication 2007, PP 63
    • D= MxO
    • where M = multiplier
    • O = offset rise
    • Image Upload 2
  5. The three bends in a 3 bend saddle use what marks on the shoe of a hand bender using the standard method? NJATC, Conduit Bending And Fabrication 2007, PP 63

    What must added to the measured distance to the center of the obstruction?

    The center bend is how much greater in degrees than the outside bends?
    • First uses the arrow
    • Second uses the rimnotch or tear drop representing the center of a 45 degree bend.
    • 3rd uses the arrow
    • Image Upload 4

    The shrink for the degree. S=CxO

    double
  6. The reduction in distance that a conduit can run per inch of offset elevation defines what term? NJATC, Conduit Bending And Fabrication 2007, PP 41

    The formula for shrink is what?
    Shrink constant

    • S = C x O
    • Where S = shrink
    • C = shrink constant in inches per inch of offset
    • O = offset rise, in inches
  7. There may be times in explosion proof work when bends may need to be accurate up to what? NJATC, Conduit Bending And Fabrication 2007, PP 36
    1/16th of an inch.
  8. When calculating the distance between bends, at a known angle, the formula used is what? NJATC, Conduit Bending And Fabrication 2007, PP 34
    • D = M x O
    • where D = distance
    • M = distance multiplier (30 deg = 2)
    • O = offset rise, in inches
  9. Define Gain. NJATC, Conduit Bending And Fabrication 2007, PP 23
    The shortcut provided by following the arc of the curve instead of the straight distance.
  10. The NEC says that there shall not be more than how many 90's (quarter bends) between pull points such as conduit bodies or boxes? NJATC, Conduit Bending And Fabrication 2007, PP 4
    4.
  11. Mechanical benders are typically used to bend conduit up to what trade size? NJATC, Conduit Bending And Fabrication 2007, PP 78

    Mechanical benders employ a lever arm and ratcheting mechanism and are also known as what?
    2"

    A chicago bender.
  12. A unigue component on a mechanical bender is the ratcheting mechanism, which includes a ___________. NJATC, Conduit Bending And Fabrication 2007, PP 80

    The pawl release is a safe feature since the handle of the bender does not release nor does the conduit? T or F?
    pawl release

    False: The Pawl release is dangerous since it releases the lever arm and the conduit.
  13. The length of the conduit between pull points is usually limited to how many feet due to fish tape length? NJATC, Conduit Bending And Fabrication 2007, PP 99
    100 feet.
  14. When bending large conduit the S = C x O is not as accurate as desired since the conduit will be too long after the bend is made. What formula is used? NJATC, Conduit Bending And Fabrication 2007, PP 102
    Image Upload 6
  15. When bending large conduit the distance between bends formula that must be used is what? Conduit Bending pp 103
    Image Upload 8
  16. In an electric bender the ________ may be used on all offsets and kicks bent regardless of the angle or the size and type of conduit. NJATC, Conduit Bending And Fabrication 2007, PP 99

    The multiplier method uses what information? NJATC, Conduit Bending And Fabrication 2007, PP 32
    Multiplier method

    • the offset rise, bend agle, distance between bends.
    • Image Upload 10
  17. The developed length for concentric bends is found using what formula? Greenlee, conduit bending handbook, PP 31

    The gain in a length of pipe being bent to a large sweep 90 is determined using what formula? Greenlee, conduit bending handbook, PP 26
    Radius x 1.57

    radius x .43
  18. There are some locations where an offset must be in the horizontal and vertical planes at the same time. This is a statement that best describes what? NJATC, Conduit Bending And Fabrication 2007, PP 42
    A rolling offset.
  19. Describe the right angle triangle used for rolling offsets NJATC, Conduit Bending And Fabrication 2007, PP 43
    Image Upload 12
  20. Regarding parallel bends, positions of the bends in adjacent lengths of conduit must be what to maintain equal spacing between offsets? NJATC, Conduit Bending And Fabrication 2007, PP 47
    • Adjusted.
    • Image Upload 14
  21. The parallel offset constant has the same value as? NJATC, Conduit Bending And Fabrication 2007, PP 48
    The shrink constant.
  22. The amount of adjustment in the layout of the bends in Parallel offsets is determined by the following formula. NJATC, Conduit Bending And Fabrication 2007, PP 48

    Once the adjustment in inches for parallel offsets is known what must be done?
    • A= CxD
    • where C= constant
    • A= adjustment in inches
    • D= distance between adjacent conduit centerline, in inches.

    It must be added or subtracted depending on the direction of the Bends.
  23. What method for offset bends produces offsets using a method if that does not require the electrician to fabricate conduit bends to a specific angle? NJATC, Conduit Bending And Fabrication 2007, PP 50
    Measured rise method for offset bends usually used in hydraulic or mechanical benders.
  24. The key to efficiently bending parallel offsets, especially with conduit of closely different sizes, is to make the parallel offset bends at what point instead of the arrow bench mark? NJATC, Conduit Bending And Fabrication 2007, PP 55
    center of bends. The center of the bends can be found by making a bend on a scrap piece of conduit and permanently transferring the mark to the bender shoe as your new benchmark.
  25. For parallel offsets that are exposed to view, The bends must be adjusted relative to what? NJATC, Conduit Bending And Fabrication 2007, PP 56
    Relative to the first conduit.
  26. A bend used to change direction in a conduit run is what? NJATC, Conduit Bending And Fabrication 2007, PP 56
    Kick.
  27. Parallel offsets can be made with conduits of different sizes by marking and pending at what? NJATC, Conduit Bending And Fabrication 2007, PP 56
    At the center of each bend.
  28. There are four variables when making saddle bends, what are they? NJATC, Conduit Bending And Fabrication 2007, PP 57
    The rise of the obstruction, the width of the obstruction, the distance to the obstruction, and the choice of the bend angles.
  29. A corner offset is a special type of four bend fabrication consisting of what? NJATC, Conduit Bending And Fabrication 2007, PP 57
    Two offsets turned at 90° relative to each other.
  30. Hand benders are manufactured with two styles of handles that bend the conduit to a 45 or a 30 degree angle when the handle is in what position?
    perpendicular to the floor.
  31. When bending rigid with a hand bender, what must be remembered about the type of bender head?
    The bender head should never be an aluminum one but rather an iron alloy head.  Check it with  a magnet.  If it is not ferrous then don’t bend imc or rigid with it since it will distort.
  32. What will dirt or build up on the shoe cause with regards to the pipe?
    It will cause the pipe to kink.
  33. take up is what measurement on a hand bender?
    it is the measurement from the arrow to the back of the ninety.
Author
johnbowens
ID
50961
Card Set
Conduit bending
Description
conduit bending
Updated