Bending parallel offsets
When conduits run side by side and all have to offset together, marking them all alike would pinch them together in one bend and spread them apart in the other. Each conduit gets the same offset, but with its marks moved a little further along than its neighbor’s, so the spacing holds all the way through.
What to measure
- Center-to-center spacing: between neighboring conduits.
- Angle: the same for every conduit.
- Offset height (optional): with it you get the marks; without it, only the shift.
- Conduits (optional): how many are in the bank, to list every conduit’s marks.
- Distance to obstruction (optional): from the conduit ends, which must be lined up square to the run. Finished at obstruction has the last conduit complete its offset there; Starts at obstruction has the first conduit start there. Either way the whole bank clears it.
How to bend it
- Number the conduits starting from the side the offset moves toward: conduit 1 is on the inside of the first bend.
- Bend conduit 1 as an ordinary offset from its marks.
- For each next conduit, move both marks Shift per conduit further from the end (they are listed under Other conduits) and bend the same offset.
- Bend every conduit with the hook facing the same end, and keep the ends lined up when you install them.
Where the numbers come from
Through a bend, the conduit on the outside has further to go, so its bend has to start later for the gap to stay the same. The offset itself is the Offset screen’s, identical for every conduit, and the shift doesn’t depend on the bender.
shift per conduit = spacing × tan(angle/2)- Center-to-center spacing
- 2"
- Angle
- 30°
- Offset height
- 6"
- Conduits
- 3
- Distance to obstruction
- 40"
- Shift per conduit
- 9/16"
- Between bends
- 11 15/16"
- Conduit 1 marks
- 25 13/16" and 37 3/4"
- Conduit 2 marks
- 26 3/8" and 38 5/16"
- Conduit 3 marks
- 26 7/8" and 38 7/8"
If it turns orange or red
Every conduit has the same offset, so they share one color, worked out as on the Offset screen: red if the bends would run into each other, orange if there is too little straight between them for the shoe. Red also shows when a mark would fall before the end of the conduit, which a short distance to the obstruction can cause.